CN106298449A - A kind of cryogenic treatment process improving ZnO film uniformity and dispersibility - Google Patents

Abstract

The invention discloses a kind of cryogenic treatment process improving ZnO film uniformity and dispersibility, put into by the ZnO film prepared in the vessel with sealing, be then added dropwise in vessel by ammonia, the consumption of described ammonia is the 0.07～0.20% of vessel volume；Whole vessel are placed in heating plate heating again, and heating-up temperature is 50～150 DEG C, and heat time heating time is 0.5～1h；After having heated, take out after sample cools down, be disposed.The present invention passes through ammonia vapor Low Temperature Heat Treatment, is effectively increased uniformity and the dispersibility of ZnO film prepared by low temperature, and the low temperature for ZnO film prepares and application has great importance；And simple for process, raw material is easy to get, and energy consumption is low, it is simple to promotion and application.

Description

A kind of cryogenic treatment process improving ZnO film uniformity and dispersibility

Technical field

The present invention relates to nano film material technical field, particularly relate to a kind of in order to improve ZnO film uniformity and to divide Dissipate the ZnO film cryogenic treatment process of property.

Background technology

ZnO material is a kind of II-VI race's wide bandgap semiconductor, a width of 3.37eV of band under room temperature；In near ultraviolet region, its Exciton bind energy is 60meV, is maximum in II-VI race, III-V wide bandgap semiconductor, and this exciton bind energy is than room temperature heat Ionization energy 26meV is much larger, and hot ionization is less likely to occur exciton, is therefore easier in room temperature than other wide bandgap semiconductor materials Under realize high efficiency stimulated emission.Additionally, ZnO fusing point is high and have the highest heat stability and chemical stability, and resist Radiation damage ability is strong, therefore has well application latent at numerous areas such as photoelectric device, piezoelectric device, surface acoustic wave devices Power.And in prepared by ZnO film, owing to ZnO high growth temperature can cause the diffusion of thin film and material substrate, simultaneously as ZnO pole Easily cause the different growth of crystal grain along C direction of principal axis oriented growth, such as preparation temperature Gao Zehui, therefore eventually result in and affect material Performance.And ZnO low-temperature epitaxy, the problem that above-mentioned high growth temperature is brought can be largely avoided, therefore a lot Field is desirable that ZnO film uses low temperature to prepare.But, ZnO film prepared by low temperature is low due to preparation temperature, therefore Uniformity and the dispersibility of ZnO are the most poor, for ensureing that the performance of material brings a difficult problem.How to improve the uniformity of ZnO film And dispersibility, the low temperature for ZnO film prepares and application has great importance.

Summary of the invention

It is an object of the invention to overcome the deficiencies in the prior art, it is provided that a kind of ZnO film preparing low temperature carries out low The method of temperature post processing, by using ammonia vapor ZnO film to be carried out Low Temperature Heat Treatment, to realize the recrystallization of ZnO, simultaneously Change the microstructure of ZnO film, thus improve uniformity and the dispersibility of the nanoparticle of ZnO film.

The purpose of the present invention is achieved by the following technical programs:

A kind of cryogenic treatment process improving ZnO film uniformity and dispersibility that the present invention provides is as follows: will prepare Good ZnO film is put in the vessel with sealing, is then added dropwise in vessel by ammonia, and the consumption of described ammonia is vessel The 0.07～0.20% of volume；Whole vessel are placed in heating plate heating again, and heating-up temperature is 50～150 DEG C, heat time heating time It is 0.5～1h；After having heated, take out after sample cools down, be disposed.

In such scheme, ZnO film of the present invention is ZnO nano grain thin film or ZnO nanorod/nanoparticle composite construction Thin film.

The present invention uses ammonia vapor (temperature is less than 150 DEG C) at low temperatures ZnO film to be carried out heat treatment, due to ammonia Heating can be evaporated, and there are similar capillary micropore in ZnO film, and the ammonia vapor after evaporation will be thin at ZnO Micropore cohesion in film, the ammonia after cohesion can dissolve short grained ZnO, by dissolving-precipitation mechanism at bigger crystal grain Crystallize, such that it is able to realize the recrystallization of ZnO, have also been changed the microstructure of ZnO film simultaneously, thus improves ZnO film The uniformity of nanoparticle and dispersibility.Its principle is as it is shown in figure 1, specific as follows:

ZnO is amphoteric oxide, is dissolved in bronsted lowry acids and bases bronsted lowry.Ammonia (NH₃·H₂O) it is the aqueous solution of ammonia, boiling point 36 DEG C, Yi Hui Send out, and there is alkalescence, NH₃·H₂O can dissolve ZnO, has the effect of similar solvent.When 25 DEG C, the surface of water can be 72mJ·m², the surface of each crystal face of ZnO can be all higher than 1000mJ m², so water can moistening ZnO surface easily.Assume to connect Feeler is 0, can obtain formula 1 according to Kelvin equation.

$P=P_0{e}^{-\frac{2\mathrm{\γ}M}{\mathrm{\ρ}RT}\·\frac{1}{r}}---\left(1\right)$

(P: concave meniscus saturated vapor pressure, P₀: plane saturated vapor pressure, g: solution surface tension, M: fluid molecule amount, r: Fluid density, R: gas constant, T: absolute temperature, r: capillary radius)

Formula (1) shows, the subnormal saturated vapor pressure of balance saturated vapor pressure of capillary tube, so solvent easily exists Capillary tube separates out drop, here it is capillary condensation.As shown in Fig. 1 (a), before using ammonia treatment, ZnO film grain size Differ, exist mesoporous, and meso-porous ZnO all can exist similar capillary micropore, such NH₃·H₂During O heating evaporation, First ammonia steam condense in micropore, the NH after cohesion₃·H₂O can dissolve the ZnO of surrounding.The dissolution law of granular solids is as public Shown in formula (2):

$C=C_0{e}^{\frac{2{\mathrm{\γ}}_{sl}M}{\mathrm{\ρ}RT}\·\frac{1}{r}}---\left(2\right)$

(C: radius is the solid particle dissolubility of r, C₀: it is block dissolubility, r: be density of solid, g_sl: it is solid liquid interface Tension force, M: be molecular weight, T: absolute temperature, r: be particle radius)

Formula (2) shows, little granule is easier to be dissolved in solvent, so the ammonia in pore mainly dissolves particle diameter Less crystal grain (see Fig. 1 (b)).Relying on mass transfer in liquid phase mechanism, dissolved ZnO separates out at bigger crystal grain, and system is from being sent to Energy reduction direction to develop, ZnO film crystal grain thus can be promoted to carry out dissolving recrystallization, thus change ZnO film Microstructure, i.e. increases crystallization degree, and improves reunion, as shown in Fig. 1 (c), grain development is more complete, degree of crystallinity increases, Crystal grain increases, number of die reduces, thus improves uniformity and the dispersibility of the nanoparticle of ZnO film.

The method have the advantages that present invention process is simple, raw material is easy to get, and ammonia used is commercially available ammonia , it is not necessary to through any process；And treatment temperature is less than 150 DEG C, and energy consumption is low, it is simple to popularization and application.The present invention passes through ammonia Water vapour Low Temperature Heat Treatment, is effectively increased uniformity and the dispersibility of ZnO film prepared by low temperature, low for ZnO film Temperature preparation and application have great importance.

Accompanying drawing explanation

Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail:

Fig. 1 is the principle schematic of the present invention；

Fig. 2 is the field of (embodiment one, two, three) after (comparative example one) and process before ZnO nano grain thin film of the present invention processes Launch scanning electron microscope cross-section photographs and surface picture (a: field emission scanning electron microscope cross-section photographs；B: surface picture)；

Fig. 3 is；(implement after (comparative example two) and process before ZnO nanorod of the present invention/nanoparticle compound structure film process Example four) field emission scanning electron microscope cross-section photographs and surface picture (a: field emission scanning electron microscope cross-section photographs；B: surface picture).

Detailed description of the invention

Comparative example one:

Comparative example one is ZnO nano grain thin film, and its preparation method is as follows:

(1) the FTO electro-conductive glass using specification to be 2.5cm × 2.5cm, processes 10min, cooling under ozone after cleaning 10min；

(2) Zn (CH of 0.6M is used₃COO)₂·2H₂The ethylene glycol monomethyl ether solution of O and 0.6M monoethanolamine, after preparing Magnetic agitation 10h, stands 10h, obtains coating liquid；

(3) using spin-coating method spin coating Seed Layer on above-mentioned FTO electro-conductive glass, the rotating speed that spin coating is used is 1000r/s Continue 6s, 3000r/s and continue 30s, with syringe, coating liquid is transferred on FTO electro-conductive glass；After spin coating, FTO is conducted electricity glass Glass is placed in 250 DEG C of heating plates heating 10min, after taking off cooling, repeats spin coating once, obtains two-layer Seed Layer；

(4) calcine in Muffle furnace, be followed successively by calcining heat 300 DEG C insulation 10min, 520 DEG C of insulation 15min, and Obtain ZnO nano grain thin film.

Embodiment one:

A kind of cryogenic treatment process improving ZnO film uniformity and dispersibility of the present embodiment:

ZnO nano grain thin film comparative example one prepared is put in the glass drying oven that sealing is good, glass drying oven Volume is 70ml, then measures 100 μ l ammonia with liquid-transfering gun and is added dropwise in glass drying oven；Again whole vessel are placed in heating plate 1h is heated at a temperature of 50 DEG C；After having heated, take out after sample cools down, be disposed.

Embodiment two:

A kind of cryogenic treatment process improving ZnO film uniformity and dispersibility of the present embodiment:

ZnO nano grain thin film comparative example one prepared is put in the glass drying oven that sealing is good, glass drying oven Volume is 70ml, then measures 100 μ l ammonia with liquid-transfering gun and is added dropwise in glass drying oven；Again whole vessel are placed in heating plate 1h is heated at a temperature of 75 DEG C；After having heated, take out after sample cools down, be disposed.

Embodiment three:

A kind of cryogenic treatment process improving ZnO film uniformity and dispersibility of the present embodiment:

ZnO nano grain thin film comparative example one prepared is put in the glass drying oven that sealing is good, glass drying oven Volume is 70ml, then measures 50 μ l ammonia with liquid-transfering gun and is added dropwise in glass drying oven；Again whole vessel are placed in heating plate 0.5h is heated at a temperature of 100 DEG C；After having heated, take out after sample cools down, be disposed.

As in figure 2 it is shown, after ammonia vapor processes, its granule of surface of embodiment one, two, three ZnO nano grain thin film Uniformity and dispersibility significantly improve.

Comparative example two:

Comparative example two is ZnO nanorod/nanoparticle compound structure film, and its preparation method is as follows:

(1) preparation of ZnO nanorod film

(1-a) preparation of ZnO Seed Layer

By Zn (CH₃COO)₂·2H₂O and C₄H₁₁NO₂It is dissolved in C₃H₈O₂(Zn (CH in mixed solution in solution₃COO)₂·2H₂O And C₄H₁₁NO₂Concentration be 0.3M), magnetic agitation 10h, stand 10h, obtain Seed Layer solution；The specification that will clean up FTO electro-conductive glass czochralski method for 2.0cm × 7.5cm impregnates Seed Layer solution, takes out, wipe out non-leading with dust-free paper after 4s The solution in electricity face, dries under natural conditions；Then calcine in Muffle furnace, at a temperature of 500 DEG C, be incubated 30min；On repeating State whole process once, prepare the ZnO Seed Layer being attached to conductive substrates surface；

(1-b) preparation of precursor solution

Precursor solution is the Zn (NO of 0.05M₃)₂·6H₂The six methine four ammonia (C of O, 0.06M₆H₁₂N₄, it is called for short HMT) Polymine ((C with 0.003M₆H₂₁N₅)_n, be called for short PEI) deionized water solution, at a temperature of 95 DEG C preheat 3h；Then Supersound process 5min, to remove the bubble in solution；

(1-c) hydrothermal synthesis method prepares ZnO nanorod film

After the above-mentioned conductive substrates being attached with ZnO Seed Layer being placed in equipped with the beaker of deionized water preheats 0.5h, Supersound process 5min, to remove the bubble on Seed Layer surface；Then by conducting surface down, lean to put in the way of reactor inner bag Entering in the reactor of warmed-up 0.5h, add the precursor solution 80mL that above-mentioned preparation is handled well, reactor assembles complete rearmounted Carry out in temperature-controllable baking oven growth response, programming rate and temperature retention time be followed successively by 90 DEG C insulation 8h, 92 DEG C insulation 4h, 95 DEG C insulation 4h, 97 DEG C insulation 4h, 105 DEG C insulation 2h, 120 DEG C insulation 1.5h, 125 DEG C insulation 1.5h, 130 DEG C insulation 1.5h, i.e. Prepare ZnO nanorod film.

(2) preparation of ZnO nanorod/nanoparticle compound structure film

Zn (the CH of preparation 0.15M₃COO)₂·2H₂O methanol solution, above-mentioned ZnO nanorod film is lain against volume is 50ml Beaker bottom, be subsequently poured into 40ml above-mentioned Zn (CH₃COO)₂·2H₂O methanol solution, seals, is put into by beaker in 60 DEG C of baking ovens Carry out chemical bath deposition reaction 42h；Sample is taken out after terminating by reaction, cleans with deionized water, after drying at a temperature of 350 DEG C Calcining, heating rate is 8 DEG C/min, is incubated 30min, i.e. prepares ZnO nanorod/nanoparticle compound structure film.

Embodiment four:

A kind of cryogenic treatment process improving ZnO film uniformity and dispersibility of the present embodiment:

ZnO nanorod comparative example two prepared/nanoparticle compound structure film puts into the vierics that sealing is good In ware, the volume of glass drying oven is 70ml, then measures 100 μ l ammonia with liquid-transfering gun and is added dropwise in glass drying oven；Again by whole Vessel are placed in heating plate heating 1h at a temperature of 100 DEG C；After having heated, take out after sample cools down, be disposed.

As it is shown on figure 3, after ammonia vapor processes, be grown in nanometer rods in embodiment four compound structure film receives Its uniformity of the grain of rice and dispersibility significantly improve.

Claims (2)

1. the cryogenic treatment process improving ZnO film uniformity and dispersibility, it is characterised in that: the ZnO that will have prepared Thin film is put in the vessel with sealing, is then added dropwise in vessel by ammonia, and the consumption of described ammonia is vessel volume 0.07～0.20%；Whole vessel are placed in heating plate heating again, and heating-up temperature is 50～150 DEG C, heat time heating time be 0.5～ 1h；After having heated, take out after sample cools down, be disposed.

Raising ZnO film uniformity the most according to claim 1 and the cryogenic treatment process of dispersibility, it is characterised in that: Described ZnO film is ZnO nano grain thin film or ZnO nanorod/nanoparticle compound structure film.