CN102942209A - Method for preparing one-dimensional nanostructure zinc oxides through changing tin doping ratio - Google Patents

Abstract

The invention relates to a method for preparing various one-dimensional nanostructure zinc oxides through changing the tin doping ratio. The method adopts zinc oxide, stannic oxide and carbon powder as reaction sources, a carbothermic reduction method is adopted, Si (100) which is plated with an Au membrane is taken as a substrate, a tin-doped one-dimensional ZnO nanostructure is prepared through chemical vapor deposition, and moreover, various-shape one-dimensional nanostructure zinc oxides are prepared through changing the tin doping ratio. The method has a simple process, and the shape changing process of the ZnO nanostructure along with the change of the tin doping ratio, which is changed from an initial nanowire array into a dendritic nanowire with surface granular deposition and is then developed into a nanoribbon, is systematically researched.

Description

Change the method that the tin dope ratio prepares one dimension Nano structure zinc oxide

Technical field

The present invention relates to a kind of preparation method of one dimension Nano structure zinc oxide, particularly a kind of the employing changes the method that the tin dope ratio prepares the one dimension Nano structure zinc oxide of different morphologies.

Background technology

ZnO has a wide range of applications in ultra-violet light-emitting device, photoelectric commutator, sensor various fields as II-IV semi-conductor important, multifunction.Therefore, reported in a large number in recent years the ZnO nano-structure of some low-dimensionals, such as nano particle, nano wire, nanotube, nano belt, nano-rings etc.The method of synthetic these nano materials mainly contains pulse excitation deposition, chemical vapour deposition, molecular beam epitaxy, thermal evaporation, electrochemical deposition.

Semi-conductor is mixed, can change electricity, optics, the magnetism characteristic of semiconductor material, thereby realize that semiconductor nano material is in the application of optoelectronic function device.Application in functional device fields such as little, nanoelectronic or photoelectrons has important effect to suitable adulterating method for ZnO.So far, the preparation method of the One-Dimensional ZnO nanostructure of mixing mainly is divided into two kinds: a kind of method is that the preparation of ZnO nano material is carried out synchronously with doping, namely adopt element simple substance or compound as raw material, by vapour deposition process, directly generate the ZnO nano-structure that mixes; Another kind method is to prepare first ZnO nano material, and then adopts thermodiffusion, the method such as ion implantation to mix element to enter material internal.

Tin is as important modifying element, for the performance generation tremendous influence of ZnO material.The Li of Taiwan university of communications etc. take Au as catalyzer, by the VLS growth mechanism, have prepared the ZnO nanowire array of different doping ratios on the Si sheet.The employing Sn powder such as the Bae of Korea S university and ZnO powder are evaporation source, spin coating one deck HAuCl on silicon chip ₄3H ₂The O ethanolic soln has prepared the nano wire that mixes as crystal seed by thermal evaporation, and nanowire surface is smooth, has simultaneously very large length-to-diameter ratio.The Deng of Hong Kong Chinese University etc. adopt thermal evaporation to prepare the nano belt with plane defect take Sn powder and ZnO powder as evaporation source.The Sheini of India Pu Na university etc. adopt the method for galvanic deposit, have prepared the nanostructure of Sn doping ZnO at the Zn sheet, and under the irradiation of visible light, the field emission performance of this material is enhanced.

Summary of the invention

The object of the present invention is to provide a kind of method that the tin dope ratio prepares one dimension Nano structure zinc oxide that changes.

Do not achieve the above object, the present invention adopts following technical scheme:

A kind ofly change the method that the tin dope ratio prepares the one-dimentional structure nano zine oxide, it is characterized in that the concrete steps of the method are:

A. with 100 silicon chips of single-sided polishing after pretreatment, adopt thermal evaporation method at silicon chip surface evaporation Au film;

B. adopt chemical Vapor deposition process, after Graphite Powder 99, zinc oxide and tindioxide fully mixed according to the mass ratio of 10:9:1, pass into argon gas and pass into oxygen with the flow velocity of 1-2 sccm with the flow velocity of 35-70 sccm, the vacuum tightness that keeps 400 mbar, then insulation is 30 minutes after rising to 900-950 ℃ with 20-30 ℃/min, temperature is down to room temperature, obtains the one-dimentional structure nano zine oxide.

The growth mechanism of Sn doped one-dimensional ZnO nano material is as follows among the present invention: owing to be coated with layer of Au film on the Si substrate, initial reaction stage is followed the VLS growth mechanism and is grown, carrying out along with reaction, Au may be absorbed to be solidly soluted on the nano wire or to form small particle and be adsorbed on nanowire surface, reaction begins to follow the VS growth mechanism, so the Au particle is not found on sample top and surface.Because in the whole reaction process, axial growth speed along with constantly carrying out of reactive deposition, obtains the ZnO one dimension Nano structure that Sn mixes greater than radial growth speed under comparatively high temps and supersaturated condition.Along with the increase of doping Sn content, meeting so that the stress of ZnO one dimension Nano structure, Zn room, surface imperfection change, thereby pattern and the structure of sample impacted.When not mixing Sn, resulting sample is nano wire.The ratio of mixing along with Sn constantly increases, and the stress of nano wire, Zn room and surface imperfection increase thereupon, and the pattern of the ZnO nano-structure that prepared Sn mixes is transitioned into the branch shape that there is the particulate state deposition on the surface from initial ZnO nano-wire.Along with SnO ₂The continuation of content increases, and the Zn partial vapor pressure is lower in the reactive system, and the Morphology of prepared sample is nano belt.

The characteristics of the inventive method are as follows: the present invention adopts ZnO, SnO ₂With carbon dust as reaction source, adopt carbothermic method, take the Si (100) that is coated with 10 nm Au films as substrate, chemical vapour deposition has prepared the One-Dimensional ZnO nanostructure of Sn doping.Change the doping ratio of tin, prepared the One-Dimensional ZnO nanostructure of different morphologies.

The present invention adopts chemical Vapor deposition process to prepare the one-dimension zinc oxide nanostructure of different morphologies by changing the tin dope ratio.Along with improving constantly of the doping ratio of tin, ZnO nano-structure at first from nano wire to the dendritic structure transition that is attached with particle, develops into to the nano belt structure subsequently.

Description of drawings

Fig. 1 is SnO ₂The SEM collection of illustrative plates of prepared tin dope ZnO one dimension Nano structure when being 0.05g:0.45g with the ZnO doping ratio;

Fig. 2 is SnO ₂The XRD figure of prepared tin dope ZnO one dimension Nano structure when being 0.05g:0.45g with the ZnO doping ratio;

Fig. 3 is SnO ₂The energy spectrogram of prepared tin dope ZnO one dimension Nano structure when being 0.05g:0.45g with the ZnO doping ratio;

Fig. 4 is SnO ₂The element doping schedule of proportion of prepared tin dope ZnO one dimension Nano structure when being 0.05g:0.45g with the ZnO doping ratio.Wherein the argon gas flow velocity is 70 sccm, 950 ℃ of reaction 30min.

Fig. 5 changes the one-dimension zinc oxide nanostructure SEM figure of the different morphologies of tin dope ratio preparation: a) SnO ₂: ZnO=0.00g:0.50g; B) SnO ₂: ZnO=0.05g:0.45g; C) SnO ₂: ZnO=0.10g:0.40g; D) SnO ₂: ZnO=0.20g:0.30g; E) SnO ₂: ZnO=0.30g:0.20g; F) SnO ₂: ZnO=0.40g:0.10g; G) SnO ₂: ZnO=0.45g:0.05g; H) SnO ₂: ZnO=0.50g:0.00g.Fixing argon gas flow velocity 70 sccm, O ₂Flow velocity is 2.0 sccm, 950 ℃ of reaction 30min.

Fig. 6 changes the one-dimension zinc oxide nanostructure XRD figure of the different morphologies of tin dope ratio preparation.

Embodiment

After now specific embodiments of the invention being described in.

Embodiment 1

Concrete preparation process of the present invention is as follows:

(1) silicon wafer N (100) of single-sided polishing was put into ethanol, acetone soln each ultrasonic 0.5 hour, remove the silicon chip surface organism, then put into the vitriol oil, hydrogen peroxide (volume ratio 3:1) mixing solutions, 80 ℃ were heated 1 hour, the oxide compound of removal silicon face, metallic impurity etc.Silicon chip after processing is put into ultrapure water ultrasonic 0.5 hour, remove the remained on surface acid solution;

(2) deposited by electron beam evaporation coating equipment adopts thermal evaporation method at the thick Au film of silicon chip surface evaporation one deck 10 nm;

(3) take by weighing 0.5 g Graphite Powder 99,0.45 g ZnO and 0.05 g tindioxide, grinding is put into quartz boat after it is fully mixed, the silicon chip that the surface is coated with 10 nm Au films be placed on powder directly over, quartz boat is put into the center warm area of tube furnace.Start vacuum pump, close vacuum pump after reaction chamber is evacuated to vacuum state.In reaction chamber, pass into argon gas (flow velocity is 70 sccm) and oxygen (flow velocity is 2 sccm), when vacuum tightness reaches 400 mbar in the reaction chamber, again start vacuum pump, guarantee that the vacuum tightness perseverance is 400 mbar in the reaction chamber.Start temperature elevation system, rise to 950 ℃ with 24 ℃/min after insulation 30 minutes.Keep gas flow rate constant, after the tube furnace temperature is down to room temperature, take out sample.

(4) fixing argon gas flow velocity 70 sccm, O ₂Flow velocity is 2.0 sccm, 950 ℃ of reaction 30min, the doping ratio of change tin, SnO ₂: the ratio of ZnO is 0.00g:0.50g, 0.05g:0.45g, 0.10g:0.40g, 0.20g:0.30g, 0.30g:0.20g, 0.40g:0.10g, 0.45g:0.05g, 0.50g:0.00g, and preparation has the one-dimension zinc oxide nanostructure of the tin dope of different morphologies.

Prepared sample detects through instrument and characterizes in above-described embodiment, and its result is as follows:

1. as shown in Figure 1, the ZnO nano material that the Sn that chemical Vapor deposition process prepares mixes is dendritic structure, and diameter is about 500 nm, and the minor matters surface is the particulate state deposition.By XRD figure spectrogram 2 as can be known, what the XRD diffraction peak was corresponding is the hexagonal Wurzite structure of ZnO, and (JCPDS card 36-1451) is consistent with body phase standard value.But, do not find SnO, SnO in the XRD figure spectrum ₂Relevant peaks, this is because Zn ²⁺Ionic radius and Sn ⁴⁺The ionic radius gap less, thereby in the vapor phase growth process, the Sn atomic diffusion has entered the ZnO lattice, some Zn ²⁺The position is by Sn ⁴⁺Replace.By can spectrogram Fig. 3 and element ratio figure Fig. 4 as can be known, the existence of Sn element is arranged in the synthetic ZnO nano-structure of gas phase really.

2. known to only have ZnO and carbon dust in raw material by Fig. 5, when not having the Sn element to exist, prepared sample is nano-wire array (a).Work as SnO ₂When being 0.05g:0.45g with the ZnO doping ratio, the Morphology Evolution of ZnO nanowire array is branch shape (b), and minor matters surfaces is the particulate state deposition, diameter than the nano wire of the Sn element that do not mix greatly.Work as SnO ₂The doping quality rise SnO ₂With the ZnO doping ratio be 0.10g:0.40g, the increase meeting of Sn constituent content so that stress, Zn room and surface imperfection increase, thereby so that the particulate state on the surface of nanostructure deposition increase.Along with SnO ₂Amount continue to increase, the ZnO nano-structure that prepared Sn mixes is progressively to nano belt transition (c-g), the particulate state deposition on surface reduces thereupon, productive rate also decreases simultaneously, this is owing to the content of Sn element in the raw material is more, cause the Zn partial vapor pressure lower, thereby affect the growth of dopant material.

3. as shown in Figure 6, along with different SnO ₂: when the ZnO doping ratio was increased to 4:1 by 1:9, the 2 θ angles at (002) peak moved right 34.66 from 34.56.Simultaneously, along with improving constantly of doping ratio, the peak width of three main peaks is in continuous increase.Along with the increase of doping ratio, the peak width of three main peaks increases thereupon, shows that the Sn element doping enters the amount of ZnO intracell in thereupon increase.

Claims (1)

1. one kind changes the method that the tin dope ratio prepares the one-dimentional structure nano zine oxide, it is characterized in that the concrete steps of the method are:

A. with 100 silicon chips of single-sided polishing after pretreatment, adopt thermal evaporation method at silicon chip surface evaporation Au film;

B. adopt chemical Vapor deposition process, after Graphite Powder 99, zinc oxide and tindioxide fully mixed according to the mass ratio of 10:9:1, pass into argon gas and pass into oxygen with the flow velocity of 1-2 sccm with the flow velocity of 35-70 sccm, the vacuum tightness that keeps 400 mbar, then insulation is 30 minutes after rising to 900-950 ℃ with 20-30 ℃/min, temperature is down to room temperature, obtains the one-dimentional structure nano zine oxide.

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