CN103074058B - Low-toxicity heat-sensitive quantum dot material and preparation method thereof - Google Patents

Abstract

The invention discloses a low-toxicity heat-sensitive quantum dot material and a preparation method thereof, and belongs to the technical field of semiconductor nanomaterial preparation. The preparation method comprises the steps as follows: by taking a Cu-doped InP quantum dot as a core, coating with a semiconductor ZnS isolation layer at first for isolating an inner material layer from an outer material layer, then coating with a semiconductor InP nanocrystal shell layer, and finally coating an outermost layer with a ZnS protection layer to form a Cu@InP/ZnS/CdSe/ZnS quantum dot. The quantum dot is highly sensitive to temperature, emits green light at normal temperature, red light at the temperature of 200 DEG C and different levels of yellow light at the intermediate temperature, and is stable in property, uniform in size and good in dispersity, and particles after the quantum dot is coated with the shell layer are in a perfect spherical shape; and as the quantum dot material prepared with the method is a non-cadmium semiconductor material, the quantum dot material has the advantage of low toxicity, accords with the green chemical synthesis concept, and is environment-friendly and strong in applicability.

Description

A kind of Low-toxicity heat-sensitive quantum dot material and preparation method thereof

Technical field

The invention belongs to semiconductor nano material preparing technical field, relate to a kind of Low-toxicity heat-sensitive quantum dot material and synthetic method thereof, this quanta point material is responsive to temperature altitude, under being embodied in condition of different temperatures, material can send out the light of different colours, and material itself and preparation process low toxic and environment-friendly thereof.

Background technology

After semiconductor material is decreased to certain critical size (1 ~ 20 nanometer) mutually gradually from body, the fluctuation of its current carrier becomes remarkable, motion is by limited, cause the increase of kinetic energy, corresponding electronic structure becomes the discontinuous of accurate division from the consecutive level structure of body, and this phenomenon is called quantum size effect.More common semi-conductor nano particles and quantum dot mainly contain II-VI, III-V and group IV-VI.The quantum dot of these kinds all very observes quantum size effect, and its character presents regular change with size, and such as absorption and emission wavelength change with dimensional change.Therefore, semiconductor-quantum-point has very important application in fields such as illumination, indicating meter, laser apparatus and biological fluorescent labellings.

Colloidal Quantum Dots research work the earliest can trace back to nineteen eighty-two, the preparation of Brus group reported first water soluble semiconductor quantum dot and optical property.Since then, some groups have carried out the preparation of different types of semiconductor-quantum-point and the work of character research in succession.Usually the colloidal nanoparticles that we know is the quantum dot of point, rod or nucleocapsid structure, and these are all the single quantum dot systems grown on a kind of particle basis.

At colloidal semiconductor nm regime, some research teams have been had to be devoted to prepare composite quantum dot system.In research in early days, the most significant once trial is the CdS-HgS-CdS(MewsA. that Mews etc. proposed in 1994; Eychmueller, A.; Weller, H.J.Phys.Chem.1994,98,934-4) system, the method that they are exchanged by surface ion successfully achieves the HgS inserting single or multiple lift between two-layer CdS, and on absorption spectrum, observed obvious red shift, but absorption spectrum is not enough to judge that every one deck quantum dot system independently can both show the electronics or optical property that we wish to obtain, in addition, composite particles system shows single wider and weak emission peak when being stimulated.Due to synthetic technology at that time and imperfection, although the proposition of this model is highly significant, in bibliographical information about particle and synthetic effect coated layer by layer poor.

Peng group was in 2005 afterwards, adopted the method for ionic adsorption to grow certain thickness ZnS between two-layer CdSe, by regulating the thickness of ZnS sealing coat, realizing inside and outside two-layer quantum dot system and whether being associated in nature.Experiment shows, this ionic adsorption growing technology accurately can control each individual layer particle growth level, thus regulate and control overall shell thickness preferably, so just achieve and be prepared in the semi-conductor nano particles that given nanoparticle core extension grows differing materials continuously.At CdSe-ZnS-CdSe system (David, B.; Bridgette B.; Peng X.J.Am.Chem.Soc.2005,127,10889-10897) in, ZnS shell thickness can grow into five layers from one deck, and ZnS is thinner as one to time two-layer, does not observe absorption and the emission peak of outer CdSe.After ZnS sealing coat reaches three to four layers, progressively there is outer stronger CdSe emission peak, the peak position of internal layer CdSe can not be affected simultaneously.In summary, Peng group, using the ZnS of greater band gap as insolated layer materials, by changing ZnS shell thickness, can obtain the composite nanoparticle with dual emission peak position.People studied the colloidal semiconductor nanoparticle of Mn doping afterwards, as Zn _1-xmn _xse/ZnCdSe system (Chih-Hao, H.; Anna, W.; Haw, Y.Acs Nano.2011,5 (12), 9511-9522), there is dual emission peak equally, and these transmittings have very strong temperature dependency.When changing temperature, two kinds of emission peaks can alternately occur.This material by means of only conversion growth conditions and controllable Two peak emission temperature range has very large potentiality to be exploited on optics temperature control sensor.

But, because the research of people in this field is mainly conceived to the discovery of model theory structure and novel material, and do not pay close attention to the susceptibility of thermo-sensitive material itself and the problem such as whether alternating temperature color obvious, so, real realize application before also have a lot of problems demand to solve.Wherein, topmost is exactly that the change of the glow color that temperature change brings is clear and definite not, and temperature and color do not have clear and definite corresponding relation, and between alternating temperature chromatic zones, span is less, only can by red to yellow.

In addition as to mention in above-mentioned background material, forefathers contain this toxic element of cadmium mostly for the research of the composite nanoparticle of this dual wavelength luminescence, well-known cadmium and compound thereof have the toxicity be bound to arouse fear, cadmium can produce respiratory tract to stimulate, chemical pneumonitis can be caused, cadmic compound is not easily by intestinal absorption, but can through breathing by body absorption, lodge in liver or kidney works the mischief, especially with the most obvious to kidney damage, show as uriniferous tubules and reclaim dysfunction, also can cause osteoporosis and soften, serious causes death.

Summary of the invention

The technical problem to be solved in the present invention is, overcomes the deficiency that background technology exists, provide a kind of color along with temperature variation clear and definite, transition interval can change to yellow from green and change to redness again, and reusable hypotoxicity is containing the Thermosensitive quantum dot material of cadmium.

Technical problem of the present invention solves by following technical scheme:

A kind of Low-toxicity heat-sensitive quantum dot material; its structure has InP quantum dot core, ZnS sealing coat, the nanocrystalline shell of InP and ZnS protective layer; the InP quantum dot of the Cu doping of described InP quantum dot core to be Fluorescent peal be 650nm ~ 800nm; Cu doping is Cu:P=1:5 ~ 20 in molar ratio, and the nanocrystalline shell of described InP is 2 ~ 4 layers of InP.

The preferred Cu:P=1:10 in molar ratio of described Cu doping; Described ZnS sealing coat is 3 ~ 6 layers of ZnS, preferably 4 layers, and described ZnS protective layer is 1 ~ 4 layer of ZnS, preferably 2 layers.

A preparation method for Low-toxicity heat-sensitive quantum dot material, has Cu to adulterate the coated technological process of coated and ZnS protective layer of coated, the nanocrystalline shell of InP of the preparation of InP quantum dot core solution, ZnS sealing coat;

The preparation process of described InP quantum dot core solution, first join in octadecylene by indium acetate and TETRADECONIC ACID, be warming up to 80 ~ 120 DEG C, wherein the mol ratio of indium acetate and TETRADECONIC ACID is 1:3.5, and the consumption of octadecylene is that every molar acetate indium uses 25 liters; Be warming up to 188 DEG C under nitrogen protection, injection octylame and concentration are the octadecylene solution of 3-(trimethyl silicon based) phosphorus of 0.2mol/L, and the octylame wherein injected and the mol ratio of indium acetate are 12:1, and the phosphorus of injection and the mol ratio of indium acetate are 1:2; Be cooled to 178 DEG C, keep cooling to 60 ~ 100 DEG C again in 30 minutes, implantation concentration is the octadecylene solution of the TETRADECONIC ACID copper of 0.005 ~ 0.02mol/L wherein, the consumption of TETRADECONIC ACID copper is Cu:P=1:5 ~ 20 in molar ratio, be warming up to 150 DEG C to keep 20 ~ 40 minutes, obtain Cu doping InP quantum dot (being designated as Cu@InP) core solution;

The coated process of described ZnS sealing coat is, first the InP quantum dot core solution that adulterated by Cu maintains 120 ~ 160 DEG C, feed intake by shell component, first inject the cation precursor solution of the zinc of one deck consumption, be warming up to 220 ~ 260 DEG C of reactions 30 ~ 45 minutes, reinject the anionic pre-cursors solution of sulphur of one deck consumption, reacts 30 ~ 45 minutes; After this keep 220 ~ 260 DEG C, the cation precursor solution of the zinc of alter least-squares one deck consumption and the anionic pre-cursors solution of sulphur are also each to react 30 ~ 45 minutes, altogether carries out 3 ~ 6 times, forms the ZnS sealing coat of 3 ~ 6 layers; Then reaction system is down to room temperature, adding volume ratio is that the chloroform of 1:10 and the mixed solvent of ethanol make quantum dot precipitate, then centrifugation, Cu doping InP nanocrystals quantum dots (being designated as Cu@InP/ZnS) that the ZnS obtaining purifying is coated;

The coated process of the nanocrystalline shell of described InP is, the InP nanocrystals quantum dots that adulterated by Cu coated for the ZnS of purification is distributed in octadecylene; The consumption of octadecylene is that the coated Cu of the every mmole ZnS InP nanocrystals quantum dots that adulterates uses 1 ~ 2 liter; Be warming up to 60 ~ 100 DEG C, vacuumize and be warming up to 120 ~ 160 DEG C more under nitrogen protection, feed intake by shell component, first add the anionic pre-cursors solution that one deck calculates the phosphorus of consumption, be warming up to 180 DEG C of reactions 30 ~ 45 minutes, the cation precursor solution reaction of the indium of the one deck that reinjects calculating consumption 30 ~ 45 minutes; After this 180 DEG C are kept, the anionic pre-cursors solution of the phosphorus of alter least-squares one deck consumption and the cation precursor solution of indium are also each to react 30 ~ 45 minutes, altogether carry out 2 ~ 3 times, form the nanocrystalline shell of InP of 2 ~ 3 layers, the Cu obtaining first coated ZnS coated InP again adulterates InP nanocrystals quantum dots (being designated as Cu@InP/ZnS/InP);

The coated process of described ZnS protective layer is, first the InP nanocrystals quantum dots solution that adulterated by the Cu of first coated ZnS coated InP again maintains 120 ~ 160 DEG C, feed intake by shell component, first inject the cation precursor solution that one deck calculates the zinc of consumption, be warming up to 220 ~ 260 DEG C of reactions 30 ~ 45 minutes, the anionic pre-cursors solution reaction of the sulphur that reinjects 30 ~ 45 minutes; After this keep 220 ~ 260 DEG C, the cation precursor solution of the zinc of alter least-squares one deck consumption and the anionic pre-cursors solution of sulphur are also each to react 30 ~ 45 minutes, altogether carries out 2 ~ 3 times, forms the ZnS protective layer of 1 ~ 4 layer; By final reaction system cool to room temperature, adding volume ratio is that the chloroform of 1:10 and the mixed solvent of ethanol make quantum dot precipitate, then centrifugation, obtains the Low-toxicity heat-sensitive quantum dot material (being designated as Cu@InP/ZnS/InP/ZnS) of purifying.

All coated process in the present invention, when coated every one deck, feeding intake the calculating of consumption by shell component can reference Chem.Mater.2010, and 22,1439.

Described Cu adulterates in the preparation process of InP quantum dot core solution, and the consumption of TETRADECONIC ACID copper is preferably Cu:P=1:10 in molar ratio.

The coated process of described ZnS sealing coat preferably carries out 4 times altogether, and the coated process of described ZnS protective layer preferably carries out 2 times altogether.

The octadecylene solution of the cation precursor solution of described zinc to be concentration the be Zinic stearas of 0.5 ~ 1mol/L; The cation precursor solution of described indium is, every mole of TETRADECONIC ACID indium is dissolved in the solution obtained in 0.48 liter of tributylphosphine and 0.52 liter of octadecylene mixed solvent; The octadecylene solution of the anionic pre-cursors solution of described sulphur to be concentration the be elemental sulfur of 0.5 ~ 1mol/L; The anionic pre-cursors solution of described phosphorus is, every mole of 3-(trimethyl silicon based) phosphorus is dissolved in the solution obtained in the mixed solvent of 0.45 liter of octylame and 0.55 liter of octadecylene.

The present invention is based on the nuclear shell structure quantum point of energy band engineering the Theory Construction differing materials composition, middle layer ZnS material effectively can completely cut off the electronic processes of inside and outside layer material, makes its each luminous and nothing interferes with each other.

Thermo-sensitive material prepared by the present invention belongs to hydrophobic material, and surface ligand is mainly chain alkyl carboxylic acid.

Can obtain solid powder sample after thermo-sensitive material purification drying prepared by the present invention, under solid state, glow color also can vary with temperature and change.

Thermosensitive type quanta point material prepared by the present invention, stable in properties, placing six months still can with temperature discoloring.

Thermosensitive quantum dot material prepared by the present invention, the coated of every layer of material all can precise thickness control, and the coated rear particle of shell is in perfect spherical, and size uniformity, monodispersity is good.

The present invention is not containing toxic heavy metals such as ubiquitous cadmium, mercury in semiconductor material, and relative environmental protection, potential applicability is strong.

To sum up, the Thermosensitive quantum dot material and preparation method thereof of a kind of nucleocapsid structure of the present invention has following beneficial effect:

1, the material of preparation is to temperature sensitive, and color variation with temperature is clear and definite.

2, the material color change interval of preparation is wide, and along with temperature changes to 200 DEG C from normal temperature, material color can taper to redness from green, middle experience yellow in various degree.

3, the material settling out of preparation, can reuse.

4, the material prepared in the solid state color also varies with temperature and changes.

5, preparation method accurately can control the coated thickness of every layer of material, and the coated rear particle of shell is in perfect spherical, and size uniformity, monodispersity is good

6, the material prepared and preparation process are strictly without cadmium, without mercury, and have hypotoxic advantage, meet the synthesis theory of Green Chemistry, environmentally friendly, potential applicability is stronger.

Accompanying drawing explanation

Fig. 1 is the Thermosensitive quantum dot material spectrogram at different temperatures of the nucleocapsid structure obtained by the order of embodiments of the invention 2,5,7,9,11,13,14.

Fig. 2 is the transmission electron microscope photo of the InP quantum dot particles that embodiment 2 obtains, and particle dia is about 2nm.

Fig. 3 is the transmission electron microscope photo of the quantum dot of the Cu@InP/ZnS structure obtained by the sequential system of embodiment 2,5,7, and particle dia is about 4.5nm.

Fig. 4 is the Cu@InP/ZnS/InP/ZnS structure quantum point transmission electron microscope photo obtained by the sequential system of embodiment 2,5,7,9,11,13, and particle dia is about 8nm.

Fig. 5 is the structural representation of a kind of Low-toxicity heat-sensitive quantum dot material of the present invention.

Embodiment

Prepare various anions and canons precursor injection liquid: the precursor injection liquid of preparation Zn, In, S, P, get the Zinic stearas of 10 mmoles and the octadecylene mixing of 20 milliliters, vacuumize logical nitrogen and be heated to 200 DEG C of dissolvings, obtain the precursor injection liquid of 0.5mol/L; Get the Zinic stearas of 10 mmoles and the octadecylene mixing of 10 milliliters, vacuumize logical nitrogen and be heated to 200 DEG C of dissolvings, obtain the precursor injection liquid of 1mol/L; Get 10 mmole TETRADECONIC ACID indiums, 4.8 liters of tributylphosphines and 5.2 liters of octadecylene mixing, vacuumize logical nitrogen and be heated to 250 DEG C of dissolvings, obtain the In precursor injection liquid of 1mol/L; Get sulphur powder and 20 milliliters of octadecylene mixing of 10 mmoles, vacuumize logical nitrogen and be heated to 140 DEG C of dissolvings, the S precursor injection liquid of obtained 0.5mol/L; Get sulphur powder and 10 milliliters of octadecylene mixing of 10 mmoles, vacuumize logical nitrogen and be heated to 140 DEG C of dissolvings, the S precursor injection liquid of obtained 1mol/L; Get 3-(trimethyl silicon based) phosphorus of 10 mmoles, mix with the octylame of 4.5 liters and the octadecylene of 5.5 liters, vacuumize logical nitrogen and be heated to 50 DEG C of dissolvings, obtain the P precursor injection liquid of 1mol/L.The doping liquid of preparation 0.005mol/LCu, gets 0.05 mmole TETRADECONIC ACID copper and mixes with 10 milliliters of octadecylenes, vacuumize logical nitrogen and heat 70 DEG C of dissolvings; The doping liquid of preparation 0.01mol/LCu, gets 0.1 mmole TETRADECONIC ACID copper and mixes with 10 milliliters of octadecylenes, vacuumize logical nitrogen and heat 70 DEG C of dissolvings; The doping liquid of preparation 0.02mol/LCu, gets 0.2 mmole TETRADECONIC ACID copper and mixes with 10 milliliters of octadecylenes, vacuumize logical nitrogen and heat 70 DEG C of dissolvings; In addition, the octadecylene solution of 3-(trimethyl silicon based) phosphorus of 0.2mol/L also will be prepared in glove box.

Four parts are below divided to illustrate the embodiment of each step of the non-cadmium Thermosensitive quantum dot material of preparation.

First part: preparation InP quantum dot core solution (embodiment 1 ~ 3)

Embodiment 1:

First; preparation InP quantum dot: the TETRADECONIC ACID of getting 0.2 mmole indium acetate and 0.7 mmole joins in 5 milliliters of octadecylenes; be warming up to 80 DEG C; after vacuumizing; be warming up to 188 DEG C under nitrogen protection, injecting 0.5 ml concn is the octadecylene solution of 0.2mol/L3-(trimethyl silicon based) phosphorus and the octylame of 1.2 mmoles, Temperature fall to 178 DEG C after injecting; keep temperature 178 DEG C reaction can obtain InP quantum dot in 30 minutes, the InP lateral size of dots obtained is about 2nm.

Then, carry out Cu doping: the InP quantum dot prepared directly is cooled to 60 DEG C, in system, instill total amount be 1 ml concn is the octadecylene solution of the TETRADECONIC ACID copper of 0.005mmol/L, be warming up to 150 DEG C again, keep temperature within 20 minutes, can obtain the InP quantum dot core solution of Cu doping, mixing Cu amount is Cu:P=1:20 in molar ratio.

Embodiment 2:

First; preparation InP quantum dot: the TETRADECONIC ACID of getting 0.2 mmole indium acetate and 0.7 mmole joins in 5 milliliters of octadecylenes; be warming up to 100 DEG C; after vacuumizing; be warming up to 188 DEG C under nitrogen protection, injecting 0.5 ml concn is the octadecylene solution of 0.2mol/L3-(trimethyl silicon based) phosphine and the octylame of 1.2 mmoles, Temperature fall to 178 DEG C after injecting; keep temperature 178 DEG C reaction can obtain InP quantum dot in 30 minutes, the InP lateral size of dots obtained is about 2nm.

Then, carry out Cu doping: the InP quantum dot prepared directly is cooled to 80 DEG C, in system, instill total amount be 1 ml concn is the octadecylene solution of the TETRADECONIC ACID copper of 0.01mmol/L, be warming up to 150 DEG C again, keep temperature within 30 minutes, can obtain the InP quantum dot core solution of Cu doping, mixing Cu amount is Cu:P=1:10 in molar ratio.

Embodiment 3:

First; preparation InP quantum dot: the TETRADECONIC ACID of getting 0.2 mmole indium acetate and 0.7 mmole joins in 5 milliliters of octadecylenes; be warming up to 120 DEG C; after vacuumizing; be warming up to 188 DEG C under nitrogen protection, injecting 0.5 ml concn is the octadecylene solution of 0.2mol/L3-(trimethyl silicon based) phosphine and the octylame of 1.2 mmoles, Temperature fall to 178 DEG C after injecting; keep temperature 178 DEG C reaction can obtain InP quantum dot in 30 minutes, the InP lateral size of dots obtained is about 2nm.

Then, carry out Cu doping: the InP quantum dot prepared directly is cooled to 100 DEG C, in system, instill total amount be 1 ml concn is the octadecylene solution of the TETRADECONIC ACID copper of 0.02mmol/L, be warming up to 150 DEG C again, keep temperature within 40 minutes, can obtain the InP quantum dot core solution of Cu doping, mixing Cu amount is Cu:P=1:5 in molar ratio.

Second section: coated ZnS sealing coat and purification (embodiment 4 ~ 7)

Embodiment 4:

The InP quantum dot core solution of Cu doping embodiment 1 ~ 3 any embodiment prepared is maintained to 120 DEG C, the coated consumption required for core solution is calculated according to charging capacity, the concentration injecting one deck consumption is the cation precursor solution of the Zn of 0.5mol/L, temperature of reaction is risen to 220 DEG C of growth quantum point shells 45 minutes, the concentration of one deck consumption of reinjecting is the anionic pre-cursors solution of the S of 0.5mol/L, same reaction 45 minutes.After this, keep 220 DEG C of alter least-squares, two kinds of precursor solutions and respectively react 45 minutes, coated 3 layers altogether.The precursor injection liquid consumption of Zn, S is: be followed successively by third layer by first: 0.24 milliliter, 0.4 milliliter, 0.58 milliliter.

Embodiment 5:

The InP quantum dot core solution of Cu doping embodiment 1 ~ 3 any embodiment prepared is maintained to 140 DEG C, the coated consumption required for core solution is calculated according to charging capacity, the concentration injecting one deck consumption is the cation precursor solution of the Zn of 0.5mol/L, temperature of reaction is risen to 240 DEG C of growth quantum point shells 40 minutes, the concentration of one deck consumption of reinjecting is the anionic pre-cursors solution of the S of 0.5mol/L, same reaction 40 minutes.After this, keep 240 DEG C of alter least-squares, two kinds of precursor solutions and respectively react 40 minutes, coated 4 layers altogether.The precursor injection liquid consumption of Zn, S is: be followed successively by by the first to the four layer: 0.24 milliliter, 0.4 milliliter, 0.58 milliliter, 0.8 milliliter.

Embodiment 6:

The InP quantum dot core solution of Cu doping embodiment 1 ~ 3 any embodiment prepared is maintained to 160 DEG C, the coated consumption required for core solution is calculated according to charging capacity, the concentration injecting one deck consumption is the cation precursor solution of the Zn of 0.5mol/L, temperature of reaction is risen to 260 DEG C of growth quantum point shells 30 minutes, the concentration of one deck consumption of reinjecting is the anionic pre-cursors solution of the S of 0.5mol/L, same reaction 30 minutes.After this, keep 260 DEG C of alter least-squares, two kinds of precursor solutions and respectively react 30 minutes, coated 6 layers altogether.The precursor injection liquid consumption of Zn, S is: be followed successively by layer 6 by first: 0.24 milliliter, 0.4 milliliter, 0.58 milliliter, 0.8 milliliter, 1 milliliter, 1.3 milliliters.

Embodiment 7:

Structure embodiment 4 ~ 6 prepared is that the quantum dot solution temperature of Cu@InP/ZnS is down to room temperature, the mixed solvent adding 1 milliliter of chloroform and 10 milliliters of ethanol makes quantum dot precipitate, then use the rotating speed centrifugation 20 minutes of per minute 4000 turns, obtain the Cu@InP/ZnS quantum dot of purifying.

Part III: the nanocrystalline shell of coated InP (embodiment 8 ~ 9)

Embodiment 8:

The method of the quantum dot embodiment 7 of nucleocapsid structure embodiment 4 ~ 6 any embodiment prepared again to be distributed to after purifying in the octadecylene of 5 milliliters and to put into three-necked flask, be warmed up to 60 DEG C, vacuumize logical nitrogen three times repeatedly, be warming up to 120 DEG C, the concentration adding one deck calculated amount is the anionic pre-cursors solution of the P of 1mol/L, be warming up to 180 DEG C of growth shells 45 minutes, concentration of reinjecting is the cation precursor solution of the In of 1mol/L, same growth 45 minutes, after this 180 DEG C of alter least-squares the moon are kept, cation precursor solution also respectively keeps 45 minutes, coated 2 layers of InP material altogether, obtain the quantum dot that structure is Cu@InP/ZnS/InP.The consumption of positive and negative ion precursor solution is: be followed successively by the second layer by first: 0.53 milliliter, 0.68 milliliter.

Embodiment 9:

The method of the quantum dot embodiment 7 of nucleocapsid structure embodiment 4 ~ 6 any embodiment prepared again to be distributed to after purifying in the octadecylene of 5 milliliters and to put into three-necked flask, be warmed up to 100 DEG C, vacuumize logical nitrogen three times repeatedly, be warming up to 160 DEG C, working concentration is the In of 1mol/L, the precursor injection liquid of P, add the anionic pre-cursors solution of the P of one deck calculated amount, be warming up to 200 DEG C of growth shells 30 minutes, concentration of reinjecting is the cation precursor solution of the In of 1mol/L, same growth 30 minutes, after this 200 DEG C of alter least-squares the moon are kept, cation precursor solution also respectively keeps 30 minutes, , coated 3 layers of InP material altogether, obtain the quantum dot that structure is Cu@InP/ZnS/InP.The consumption of positive and negative ion precursor solution is: be followed successively by third layer by first: 0.53 milliliter, 0.68 milliliter, 0.85 milliliter.

Part IV: coated ZnS protective layer and purification (embodiment 10 ~ 13)

Embodiment 10:

On the quantum dot basis of the nucleocapsid structure of embodiment 8 or 9 preparation, coated 1 layer of ZnS material is to play stabilization again, the quantum dot solution of nucleocapsid structure embodiment 8 or 9 prepared maintains 120 DEG C, the concentration adding one deck calculated amount is the cation precursor solution of the Zn of 1mol/L, be warming up to 220 DEG C of growth shells 45 minutes, the concentration of one deck calculated amount of reinjecting is the anionic pre-cursors solution of the S of 1mol/L, same growth 45 minutes, obtains the temperature-sensitive quantum dot solution that structure is Cu@InP/ZnS/InP/ZnS.The consumption of positive and negative ion precursor solution is: 1 milliliter.

Embodiment 11:

On the quantum dot basis of the nucleocapsid structure of embodiment 8 or 9 preparation, coated 2 layers of ZnS material are to play stabilization again, working concentration is the Zn of 1mol/L, the precursor injection liquid of S, the quantum dot solution of nucleocapsid structure embodiment 8 or 9 prepared maintains 140 DEG C, add the cation precursor solution of the Zn of one deck calculated amount, be warming up to 260 DEG C of growth shells 30 minutes, the anionic pre-cursors solution of the S of one deck calculated amount of reinjecting, same growth 30 minutes, after this 260 DEG C of alter least-squares sun are kept, anionic pre-cursors solution also respectively keeps 30 minutes, coated 2 layers of InP material altogether, obtain the temperature-sensitive quantum dot solution that structure is Cu@InP/ZnS/InP/ZnS.The consumption of positive and negative ion precursor solution is: be followed successively by the second layer by first: 1 milliliter, 1.2 milliliters.

Embodiment 12:

On the quantum dot basis of the nucleocapsid structure of embodiment 8 or 9 preparation, coated 4 layers of ZnS material are to play stabilization again, working concentration is the Zn of 1mol/L, the precursor injection liquid of S, the quantum dot solution of nucleocapsid structure embodiment 8 or 9 prepared maintains 140 DEG C, add the cation precursor solution of the Zn of one deck calculated amount, be warming up to 260 DEG C of growth shells 30 minutes, the anionic pre-cursors solution of the S of one deck calculated amount of reinjecting, same growth 30 minutes, after this 260 DEG C of alter least-squares sun are kept, anionic pre-cursors solution also respectively keeps 30 minutes, coated 4 layers of InP material altogether, obtain the temperature-sensitive quantum dot solution that structure is Cu@InP/ZnS/InP/ZnS.The consumption of positive and negative ion precursor solution is: be followed successively by by the first to the four layer: 1 milliliter, 1.2 milliliters, 1.4 milliliters, 1.7 milliliters.

Embodiment 13:

It is the temperature-sensitive quantum dot solution cool to room temperature of Cu@InP/ZnS/InP/ZnS by structure prepared by embodiment 10 ~ 12 any embodiment, the mixed solvent adding 1 milliliter of chloroform and 10 milliliters of ethanol makes quantum dot precipitate, then use the rotating speed centrifugation 20 minutes of per minute 4000 turns, the structure namely obtaining purifying is the Low-toxicity heat-sensitive quantum dot material of Cu@InP/ZnS/InP/ZnS.

Embodiment 14:

Embodiment 13 being precipitated the structure obtained is that the Thermosensitive quantum dot material solid sample of Cu@InP/ZnS/InP/ZnS is dried in vacuum drying oven, finally obtain solid powder sample, carry out alternating temperature fluorometric investigation, obtain spectrum as shown in Figure 1,20 DEG C time, the fluorescence quantum efficiency of the nanocrystalline shell of the InP due to green light is far above the fluorescence quantum efficiency of the nuclear matter Cu@InP glowed, and therefore material monolithic is in green; Because the nanocrystalline shell of InP is heat-labile, along with temperature raises, green glow is cancellation gradually, 200 DEG C time, the complete cancellation of green glow, and nuclear matter Cu@InP is heat-staple, along with temperature raises, ruddiness almost keeps original efficiency, therefore, when temperature is to about 200 DEG C, material monolithic just shows ruddiness, completely when medium temperature, green glow decrease in efficiency but completely cancellation, material monolithic presents gold-tinted in various degree.

Claims (7)

1. a Low-toxicity heat-sensitive quantum dot material, its structure has InP quantum dot core, ZnS sealing coat, the nanocrystalline shell of InP and ZnS protective layer, the InP quantum dot of the Cu doping of described InP quantum dot core to be Fluorescent peal be 650nm ~ 800nm, Cu doping is Cu:P=1:5 ~ 20 in molar ratio, and the nanocrystalline shell of described InP is 2 ~ 4 layers of InP; Described ZnS sealing coat is 3 ~ 6 layers of ZnS, and described ZnS protective layer is 1 ~ 4 layer of ZnS.

2. a kind of Low-toxicity heat-sensitive quantum dot material according to claim 1, is characterized in that, described Cu doping is Cu:P=1:10 in molar ratio.

3. a kind of Low-toxicity heat-sensitive quantum dot material according to claim 1, is characterized in that, described ZnS separation layer thickness is 4 layers of ZnS, and described ZnS protective layer thickness is 2 layers of ZnS.

4. a preparation method for the Low-toxicity heat-sensitive quantum dot material of claim 1, has Cu to adulterate the coated technological process of coated and ZnS protective layer of coated, the nanocrystalline shell of InP of the preparation of InP quantum dot core solution, ZnS sealing coat;

The preparation process of described InP quantum dot core solution, first join in octadecylene by indium acetate and TETRADECONIC ACID, be warming up to 80 ~ 120 DEG C, wherein the mol ratio of indium acetate and TETRADECONIC ACID is 1:3.5, and the consumption of octadecylene is that every molar acetate indium uses 25 liters; Be warming up to 188 DEG C under nitrogen protection, injection octylame and concentration are the octadecylene solution of 3-(trimethyl silicon based) phosphorus of 0.2mol/L, and the octylame wherein injected and the mol ratio of indium acetate are 12:1, and the phosphorus of injection and the mol ratio of indium acetate are 1:2; Be cooled to 178 DEG C, keep cooling to 60 ~ 100 DEG C again in 30 minutes, implantation concentration is the octadecylene solution of the TETRADECONIC ACID copper of 0.005 ~ 0.02mol/L wherein, the consumption of TETRADECONIC ACID copper is Cu:P=1:5 ~ 20 in molar ratio, be warming up to 150 DEG C to keep 20 ~ 40 minutes, obtain Cu doping InP quantum dot core solution;

The coated process of described ZnS sealing coat is, first the InP quantum dot core solution that adulterated by Cu maintains 120 ~ 160 DEG C, feed intake by shell component, first inject the cation precursor solution of the zinc of one deck consumption, be warming up to 220 ~ 260 DEG C of reactions 30 ~ 45 minutes, reinject the anionic pre-cursors solution of sulphur of one deck consumption, reaction 30 ~ 45 minute; After this keep 220 ~ 260 DEG C, the cation precursor solution of the zinc of alter least-squares one deck consumption and the anionic pre-cursors solution of sulphur are also each to react 30 ~ 45 minutes, altogether carries out 3 ~ 6 times, forms the ZnS sealing coat of 3 ~ 6 layers; Then reaction system is down to room temperature, adding volume ratio is that the chloroform of 1:10 and the mixed solvent of ethanol make quantum dot precipitate, then centrifugation, the Cu doping InP nanocrystals quantum dots that the ZnS obtaining purifying is coated;

The coated process of the nanocrystalline shell of described InP is, the InP nanocrystals quantum dots that adulterated by Cu coated for the ZnS of purification is distributed in octadecylene; The consumption of octadecylene is that the coated Cu of the every mmole ZnS InP nanocrystals quantum dots that adulterates uses 1 ~ 2 liter; Be warming up to 60 ~ 100 DEG C; vacuumize and be warming up to 120 ~ 160 DEG C more under nitrogen protection, feed intake by shell component, first add the anionic pre-cursors solution that one deck calculates the phosphorus of consumption; be warming up to 180 DEG C of reactions 30 ~ 45 minutes, the one deck that reinjects calculates the cation precursor solution reaction of the indium of consumption 30 ~ 45 minutes; After this 180 DEG C are kept, the anionic pre-cursors solution of the phosphorus of alter least-squares one deck consumption and the cation precursor solution of indium are also each to react 30 ~ 45 minutes, altogether carry out 2 ~ 3 times, form the nanocrystalline shell of InP of 2 ~ 3 layers, the Cu obtaining first coated ZnS coated InP again adulterates InP nanocrystals quantum dots;

The coated process of described ZnS protective layer is, first the InP nanocrystals quantum dots solution that adulterated by the Cu of first coated ZnS coated InP again maintains 120 ~ 160 DEG C, feed intake by shell component, first inject the cation precursor solution that one deck calculates the zinc of consumption, be warming up to 220 ~ 260 DEG C of reactions 30 ~ 45 minutes, the anionic pre-cursors solution reaction of the sulphur that reinjects 30 ~ 45 minutes; After this keep 220 ~ 260 DEG C, the cation precursor solution of the zinc of alter least-squares one deck consumption and the anionic pre-cursors solution of sulphur are also each to react 30 ~ 45 minutes, altogether carries out 2 ~ 3 times, forms the ZnS protective layer of 1 ~ 4 layer; By final reaction system cool to room temperature, adding volume ratio is that the chloroform of 1:10 and the mixed solvent of ethanol make quantum dot precipitate, then centrifugation, obtains the Low-toxicity heat-sensitive quantum dot material of purifying.

5. the preparation method of a kind of Low-toxicity heat-sensitive quantum dot material according to claim 4, is characterized in that, described Cu adulterate InP quantum dot core solution preparation process in the consumption of TETRADECONIC ACID copper be Cu:P=1:10 in molar ratio.

6. the preparation method of a kind of Low-toxicity heat-sensitive quantum dot material according to claim 4 or 5, is characterized in that, the coated process of described ZnS sealing coat carries out 4 times altogether, and the coated process of described ZnS protective layer carries out 2 times altogether.

7. the preparation method of a kind of Low-toxicity heat-sensitive quantum dot material according to claim 4, is characterized in that, the octadecylene solution of the cation precursor solution of described zinc to be concentration the be Zinic stearas of 0.5 ~ 1mol/L; The cation precursor solution of described indium is, every mole of TETRADECONIC ACID indium is dissolved in the solution obtained in 0.48 liter of tributylphosphine and 0.52 liter of octadecylene mixed solvent; The octadecylene solution of the anionic pre-cursors solution of described sulphur to be concentration the be elemental sulfur of 0.5 ~ 1mol/L; The anionic pre-cursors solution of described phosphorus is, every mole of 3-(trimethyl silicon based) phosphorus is dissolved in the solution obtained in the mixed solvent of 0.45 liter of octylame and 0.55 liter of octadecylene.