CN1315605C - Supersonic liquid phase reduction process for preparing monodisperse nano germanium crystal - Google Patents

Abstract

The present invention discloses a supersonic liquid phase reduction process for preparing a monodisperse nanometer germanium crystal. The present invention adopts a method that an approximate monodisperse nanometer germanium crystal is prepared through reducing germanium chloride by metal hydride under the condition of ultrasonic reaction. In the preparation method, in order to promote the formation of the nanometer germanium crystal, ultrasonic water bath with high energy is adopted to replace a high-temperature reaction environment to promote the formation of the nanometer germanium crystal and the dispersion of the nanometer germanium crystal in solution, and simultaneously, the metal hydride with strong reduction capability is adopted to be reductant, which can guarantee the preparation of the approximate monodisperse nanometer germanium crystal under the condition of room temperature. The influence for preparing the nanometer germanium crystal by different reductant, different reaction conditions and different precursor concentration is compared, and a better method for preparing the nanometer germanium crystal is found according to an experiment result. The method for preparing the monodisperse nanometer germanium crystal has important significance for researching the relationship of nanometer material performance and nanometer material dimension, and simultaneously, the present invention has high practical value in semiconductor device design and manufacture.

Description

Supersonic liquid phase reduction prepares the method for monodisperse germanium nanocrystal

Technical field

The present invention relates to technical field of material, particularly a kind of supersonic liquid phase reduction prepares the method for monodisperse germanium nanocrystal.

Background technology

Nano science and nanometer technology are current one of the most great-hearted research fields, and two during the decade in the past, and people sharply increase the interest of nano particle.Research purpose is " size of control material obtains new capability ".The long-pending big and specific surface chemistry performance of nano grain surface makes it be used to optimize activity of such catalysts for a long time.The dimension relationship performance of nano magnetic particle has obtained widely using, as at information storage technology.The Nano semiconductor particle has the optical property of size adjustable, has been used for photoelectric instrument.Though nano particle is in information technology, electronics, medical science, play an important role on the fields such as biotechnology, environment, the energy and national security, but can a challenge that face be controllably prepare specific nano particle, for example, the high-quality nano particle of single dispersion and given shape.A lot of nano materials have with kind massive material distinct, excellent physics and chemical property.Use these new materials, the Stability Analysis of Structures Journal of Sex Research of material is absolutely necessary.No matter be basic research, or the application of novel nano-material, crystallite dimension is the research field that receives much attention to the influence of nanoparticle structure stability always.Particle diameter by the control material can be used for controlling the performance of material, has strong dependence such as the electricity and the optical property of metal and semiconductor nanoparticle for nanocrystalline size.Therefore since Gleiter proposed the notion of nano material, the relation research to nano ZnO and particle diameter in the nanoscale scope had obtained carrying out widely.

The semi-conducting material of nano-scale is owing to have very special electricity and optical property, and at electronic device, the photonic device aspect has very large potential application.In a lot of applications, one narrow, and the particle size distribution that can reproduce is very important.Therefore people show high interest to the preparation of preparation monodispersity nano particle.A lot of Si of preparation and the nanocrystalline method of Ge have been proposed on the document, comprise the solid phase evaporation-condensation, chemical vapor deposition (CVD), ion injects, microemulsion method, and reduce methods such as Ge precursor with metal Na, Li etc., it is to carry out under HTHP that the shortcoming of these methods prepares nanocrystalline exactly, or the amorphous particle that will make at low temperatures just can obtain nanocrystallinely through HTHP heat treatment, and preparation nanocrystalline material condition harshness, cost is high and the particle diameter skewness of the nano particle that obtains.Disclose the performance of semiconductor nano material and the relation between the nano particle diameter, the preparation of dispersed nano particle is a matter of utmost importance.

Summary of the invention

The purpose of this invention is to provide a kind of easy, supersonic liquid phase reduction prepares the method for monodisperse germanium nanocrystal cheaply.

The technical solution used in the present invention is that the step of this method is as follows:

One. material mixture ratio

Concentration is 99.99% germanium tetrachloride (GeCl ₄),

Concentration is 98% sodium borohydride (NaBH ₄),

Concentration is 98% aluminium lithium hydride (LiAlH ₄),

Concentration is 85% hydrazine hydrate (N ₂H ₄H ₂O),

Octane (C ₈H ₁₈Chemical pure),

Oxolane (C ₄H ₈The O chemical pure is called for short THF),

Absolute ethyl alcohol (C ₂H ₆The O chemical pure),

GeCl wherein ₄With NaBH ₄Or LiAlH ₄Or N ₂H ₄H ₂The mole proportioning of O is 1: 4～8, GeCl in the reaction system ₄With the volume ratio of THF be 1: 6～8,0.01mol/l GeCl ₄Tetrahydrofuran solution and the volume ratio of octane be 2: 1～1.5;

All reagent are bought i.e. usefulness, all do not pass through purification process;

Two. preparation process

1) anhydrous GeCl ₄Be dissolved in and form 0.01mol/l solution, NaBH among the THF ₄Be dissolved in and form 0.06～1mol/l solution, LiAlH in the absolute ethyl alcohol ₄Be dissolved in and form 0.06mol/l solution, N among the THF ₂H ₄H ₂O this as 85% the aqueous solution;

2) with TH and octane volume ratio be 6: 1～0.8 mixed solution, preparation process 1) described in a kind of reductant solution evenly be mixed to join in the reaction vessel, then reaction vessel is put into the ultrasonic water bath that supersonic frequency is 40～60KHz;

3) 0.01mol/lGeCl ₄Tetrahydrofuran solution and the mixed solution of octane splash into by syringe in the mixed solution of reaction vessel, as first GeCl ₄Splash into afterreaction and sharply carry out, emit a large amount of H ₂, because the generation gradually of germanium nano particle, the color of mixture is from the colourless canescence that becomes, the time of carrying out that reacts completely is 30-50 minute.

The useful effect that the present invention has is:

1) this preparation method is simple, and cost is low, and condition is not harsh;

2) the germanium nanocrystal particle diameter that makes of this preparation method is little, even size distribution;

3) this preparation method adopts ultrasonic solution to prepare germanium nanocrystal first.

The method that this preparation has a monodispersity germanium nanocrystal is significant with the nano material size relationship for the research nano ZnO, has very high practical value and fine prospect simultaneously in the design of semiconductor devices, manufacturing.

Description of drawings

Fig. 1. adopt TEM, SAED and the particle diameter distribution map of the germanium nanocrystal that different reducing agents make;

(a) adopt NaBH ₄(b) adopt LiAlH ₄(c) adopt N ₂H ₄H ₂O; (d) single nanocrystalline diffraction spot;

Fig. 2. prepare the TEM and the particle diameter distribution map of germanium nanocrystal when adopting the differential responses condition;

(a) adopt the ultrasonic reaction condition; (b) adopt the magnetic agitation reaction condition;

Fig. 3. adopt different GeCl ₄The TEM and the particle diameter distribution map that prepare germanium nanocrystal during concentration;

(a) adopt GeCl ₄Concentration is 0.01 * 10 ^-3Mol/l; (b) adopt GeCl ₄Concentration is 0.1 * 10 ^-3Mol/l

The specific embodiment

Embodiment 1

Carry out according to preparation process, adopt concrete GeCl ₄Amount is the THF solution of 10ml 0.01mol/l, and adopting reducing agent shown in Fig. 1 (a) is NaBH ₄Ethanolic solution for 10ml 0.06mol/l; Adopting reducing agent shown in Fig. 1 (b) is LiAlH ₄Consumption be the THF solution of 10ml 0.06mol/l; It is 85%N that Fig. 1 (c) adopts reducing agent ₂H ₄H ₂O solution 1ml.It is to react 30 minutes under the effect of 40KHz ultrasonic wave in supersonic frequency all that institute responds.

Embodiment 2

Fig. 2 (a) sample carries out according to preparation process, adopts concrete GeCl ₄Amount is the THF solution of 10ml 0.01mol/l, adopts reducing agent NaBH ₄Consumption is the ethanolic solution of 10ml 0.06mol/l.Being reflected at supersonic frequency is to react 30 minutes under the effect of 50KHz ultrasonic wave.The reaction of Fig. 2 (b) sample is to carry out in the 300r/min magnetic agitation process in stir speed (S.S.), adopts concrete GeCl ₄Amount is the THF solution of 10ml 0.01mol/l, and the employing reducing agent is NaBH ₄Concrete consumption is the ethanolic solution of 10ml 0.06mol/l, and the reaction time is 30 minutes.

Embodiment 3

Fig. 3 (a) sample carries out according to preparation process, adopts concrete GeCl ₄Amount is the THF solution of 10ml 0.01mol/l, reducing agent NaBH ₄Concrete consumption is the ethanolic solution of 10ml 0.06mol/l.Fig. 3 (b) adopts concrete GeCl ₄Amount is the THF solution of 10ml 0.1mol/l, and reducing agent is NaBH ₄Concrete consumption is the ethanolic solution of 10ml0.6mol/l.Institute responds and all reacted 30 minutes under ultrasonication.

Claims (1)

1, a kind of supersonic liquid phase reduction prepares the method for monodisperse germanium nanocrystal, it is characterized in that the step of this method is as follows:

One. material mixture ratio

Concentration is 99.99% germanium tetrachloride GeCl ₄,

Concentration is 98% sodium borohydride NaBH ₄,

Concentration is 98% aluminium lithium hydride LiAlH ₄,

Concentration is 85% hydrazine hydrate N ₂H ₄H ₂O,

Octane C ₈H ₁₈,

Oxolane C ₄H ₈O,

Absolute ethyl alcohol C ₂H ₆O,

GeCl wherein ₄With NaBH ₄Or LiAlH ₄Or N ₂H ₄H ₂The mole proportioning of O is 1: 4～8, GeCl in the reaction system ₄With the volume ratio of oxolane be 1: 6～8,0.01mol/l GeCl ₄Tetrahydrofuran solution and the volume ratio of octane be 2: 1～1.5;

All reagent are bought i.e. usefulness, all do not pass through purification process;

Two. preparation process

1) anhydrous GeCl ₄Be dissolved in and form 0.01mol/l solution, NaBH in the oxolane ₄Be dissolved in and form 0.06～1mol/l solution, LiAlH in the absolute ethyl alcohol ₄Be dissolved in and form 0.06mol/l solution, N in the oxolane ₂H ₄H ₂O this as 85% the aqueous solution;

2) with oxolane and octane volume ratio be 6: 1～0.8 mixed solution, preparation process 1) described in a kind of reductant solution evenly be mixed to join in the reaction vessel, then reaction vessel is put into the ultrasonic water bath that supersonic frequency is 40～60KHz;

3) 0.01mol/lGeCl ₄Tetrahydrofuran solution and the mixed solution of octane splash into by syringe in the mixed solution of reaction vessel, as first GeCl ₄Splash into afterreaction and sharply carry out, emit a large amount of H ₂, because the generation gradually of germanium nano particle, the color of mixture is from the colourless canescence that becomes, the time of carrying out that reacts completely is 30-50 minute.

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