CN114717535A

CN114717535A - Method for preparing wurtzite InGaN nanorods on silicon substrate

Info

Publication number: CN114717535A
Application number: CN202210275260.4A
Authority: CN
Inventors: 李天保; 黄鹏达; 赵庆江; 胡栋; 张艳; 许并社
Original assignee: Taiyuan University of Technology
Current assignee: Taiyuan University of Technology
Priority date: 2022-03-21
Filing date: 2022-03-21
Publication date: 2022-07-08
Anticipated expiration: 2042-03-21
Also published as: CN114717535B

Abstract

The invention belongs to the technical field of preparation of InGaN nanorods, and provides a method for preparing wurtzite InGaN nanorods on a silicon substrate. Firstly, ammoniating the surface of a silicon substrate by ammonia gas, and forming Si-N bonds on the treated silicon surface and Si dangling bonds on the saturated silicon surface; GaCl3 and InCl3 are conveyed into a reaction chamber with a silicon substrate In an N2 mode, GaCl3 and InCl3 are heated, GaCl3 and InCl3 In a gas phase form Ga and In liquid drops on the surface of the substrate under the actions of thermal decomposition and hydrogen reduction, the liquid drops are accumulated to form nuclei, and finally the nuclei react with NH3 In the gas phase to generate wurtzite InGaN. The application of the GaN-based material In the fields of photoelectric devices, photovoltaic cells, carbon neutralization and the like is expanded, and InGaN with adjustable In component brings more selectivity; the method has important significance for solving the problems that the existing InGaN material is complex In growth process, difficult and uneven In doping and the like.

Description

Method for preparing wurtzite InGaN nanorods on silicon substrate

Technical Field

The invention belongs to the technical field of preparation of InGaN thin film devices, and particularly relates to a method for preparing wurtzite InGaN nanorods on a silicon substrate.

Background

In_xGa_1-xN is an alloy formed by GaN and InN, natural InGaN crystals do not exist in nature, and the N can be obtained through artificial synthesis. The InGaN crystal researched at present mainly has three structures, namely a wurtzite structure, a sphalerite structure and a sodium chloride structure. Wurtzite belongs to a thermodynamically stable structure, while the zincblende structure is a thermodynamically metastable structure that can only be obtained under specific growth conditions. The last sodium chloride structure, with four-fold rotational symmetry, can only be obtained under very high pressure conditions. At normal temperature and pressure, In_xGa_1-xThe crystal structure of the N material exists primarily in the form of a wurtzite structure. The silicon substrate also has the advantages of low cost, easy processing, good conductivity, good thermal stability and the like, so that the silicon substrate is suitable for industrial production of In_xGa_1- _xFor an N material photoelectric device, the InGaN crystal with a wurtzite structure is grown on a silicon substrate, so that the economic cost can be reduced and the good crystal quality can be ensured while the InGaN crystal is produced in a large scale.

Due to the characteristics of the InGaN such as the adjustability of band gap from ultraviolet to infrared, excellent chemical stability and high-efficiency field emission performance, the InGaN material becomes the most attractive candidate material in the fields of Light Emitting Diodes (LEDs), lasers, photovoltaic cells, solar PEC water decomposition and the like. However, in all types of devices fabricated from InGaN, their Quantum Efficiency (QE), photoluminescence efficiency (PL) rapidly decrease with increasing indium composition, and the decrease in efficiency of each type of device is associated with the generation of stress strain within the material, such as the presence of miscible interstitial phases, lack of lattice matched substrates, and other problems that complicate the growth of single crystal, high indium composition, low dislocation density InGaN materials.

In 1991, N. Yoshimoto used metal organic vapor phase epitaxyAn InGaN single crystal thin film was grown on a sapphire substrate by the (MOCVD) technique, and photoluminescence was observed for the first time; but it has problems of carbon pollution and high process cost. In 2012, the Peidong Yang adopts a Halide Chemical Vapor Deposition (HCVD) method to deposit InGaN nanowires on a silicon wire array, so as to prepare InGaN nanowires with a three-dimensional multilayer structure; the process cost is greatly reduced, but the problems of less In doping amount, no obvious photoluminescence signal and the like exist. In addition, Peidong Yang GaCl₃And InCl₃Put into different quartz tubes, and the surface of the substrate is directly connected with NH₃The problems of low InGaN nucleation density on the substrate, uneven In composition, obvious component gradient difference and the like are easily caused by gas flow contact.

Disclosure of Invention

The invention provides a method for preparing wurtzite InGaN nanorods on a silicon substrate to solve the defects in the technology.

The invention is realized by the following technical scheme: a method for preparing wurtzite InGaN nanorods on a silicon substrate comprises the steps of firstly carrying out ammoniation treatment on the surface of the silicon substrate by ammonia gas, forming Si-N bonds on the treated silicon surface, and saturating Si dangling bonds on the silicon surface; then GaCl3 and InCl3 are conveyed into a reaction chamber with a silicon substrate In an N2 mode, GaCl3 and InCl3 are heated, GaCl3 and InCl3 In a gas phase form Ga and In liquid drops on the surface of the substrate under the action of thermal decomposition and hydrogen reduction, the liquid drops are accumulated to form nuclei, and finally the nuclei react with NH3 In the gas phase to generate wurtzite InGaN.

The method comprises the following specific steps:

(1) equipment installation: placing the silicon substrate into a reaction zone of a tube furnace; three small quartz inner tubes with the diameter of 20mm are placed into a quartz outer tube with the diameter of 80mm, wherein the two small quartz inner tubes are arranged above the quartz outer tube, one small quartz inner tube is arranged below the quartz outer tube, and the two small quartz inner tubes above the quartz outer tube respectively transmit N2 and NH3 into the quartz outer tube; GaCl is placed in the quartz inner tube at the lower part₃And InCl₃Introduction of N₂As InCl₃And GaCl₃The carrier gas of (4); 400-sodium-dodecyl benzene 600sccmN before reaction₂Used for cleaning and diluting reactants, and carrying out reaction under atmospheric pressure;

(2) ammoniation treatment of a silicon substrate: atmospheric pressureAmmoniation treating silicon substrate, introducing 1000-1500 sccmnNH when the temperature of reaction zone is raised to 350 DEG C₃Keeping for 15min-25 min; forming Si-N bonds on the silicon surface after treatment;

(3) growing the InGaN nanorods: NH (NH)₃The flow rate is unchanged; adjusting the flow rate of the N2 carrier gas to 250-; controlling the temperature of the reaction zone to 550 ℃ and 650 ℃, and heating the InCl₃Heating GaCl at 380-420 deg.C₃The growth time is 20-40min when the temperature is 70-90 ℃.

The length of the upper small quartz inner tube is 100 mm; the length of the lower quartz inner tube is 1700 mm.

The practical applicability and the economical efficiency of devices such as LED photoelectric devices, field emitters and photoelectrodes in the field of solar PEC water decomposition are all considered during production. When silicon is selected as the substrate, the problems of insufficient heat dissipation, high process cost and the like can be effectively solved by the characteristics of thermal stability, conductivity, easiness in processing and the like of the silicon.

According to the method, the wurtzite InGaN nanorods are grown by taking silicon as a substrate, so that on one hand, the application of the GaN-based material In the fields of photoelectric devices, photovoltaic cells, carbon neutralization and the like is expanded, and InGaN with adjustable In components brings more selectivity; on the other hand, reacting GaCl₃And InCl₃Put into the same quartz tube, and NH is introduced into the quartz small tube above the quartz small tube₃The method not only can ensure that InGaN uniformly grows on the silicon substrate and reduce the component gradient difference, but also is beneficial to solving the problems of complex growth process, difficult and non-uniform In doping and the like of the existing InGaN material.

Drawings

FIG. 1 is a schematic diagram of an HCVD apparatus used in the present invention;

FIG. 2 is a schematic diagram of the growth process of wurtzite InGaN nanorods prepared on a silicon substrate according to the present invention;

FIG. 3 is an electron microscopic Scan (SEM) of a sample of example 1;

FIG. 4 is an X-ray diffraction pattern (XRD) of the sample of example 1;

FIG. 5 is a photoluminescence spectrum (PL) of a sample of example 1;

FIG. 6 is a photo-amperometric graph of a sample of example 1 applied to photoelectrochemical water splitting;

FIG. 7 is a 40min photocurrent stability test chart of the sample of example 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments; all other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs and the disclosures and references cited herein and the materials to which they refer are incorporated by reference.

Those skilled in the art will recognize that equivalents to the specific embodiments described, as may be learned by routine experimentation, are intended to be encompassed by the present application.

The experimental procedures in the following examples are conventional unless otherwise specified. The instruments used in the following examples are, unless otherwise specified, laboratory-standard instruments; the experimental materials used in the following examples were purchased from a conventional biochemical reagent store unless otherwise specified.

Example 1: a method for preparing wurtzite InGaN nanorods on a silicon substrate comprises the following specific steps:

(1) tube cleaning and reactant dilution: 400sccmN is respectively introduced into the upper quartz tube and the lower quartz tube₂After which the reaction zone begins to warm up.

(2) Ammoniation treatment of a silicon substrate: the pressure of the ammoniation treatment of the silicon substrate is atmospheric pressure, and 1300sccmnH is introduced when the temperature of a reaction zone is 350 DEG C₃Keeping for 20 min; after treatment, Si-N bonds are formed on the silicon surface, so that the residual stress of the silicon surface is reduced, and the InGaN is easier to nucleate on the silicon surface.

(3) Growing the InGaN nanorods: NH (NH)₃The flow rate was constant. Adjusting N₂The carrier gas flow rate was 250 sccm. The temperature of the reaction zone is controlled to 600 ℃,heating of InCl₃Heating to 400 deg.C GaCl₃The growth time is 30min when the temperature is 90 ℃.

The wurtzite InGaN nanorod samples prepared on the silicon substrate in example 1 were subjected to surface morphology and structure analysis, respectively. Fig. 3 is an electron microscopic Scanning (SEM) image of the sample of example 1, from which it can be seen that the average diameter of the grown InGaN nanorods is 250nm, the InGaN nanorods exhibit a vertically aligned morphology with a small taper and a large nucleation density. FIG. 4 is the X-ray diffractometer analysis (XRD) spectrum of the sample of example 1, from which it can be seen that the sample orientation is good, mainly growing in the direction perpendicular to the wurtzite (002) plane, and the peak half width at the maximum of the (002) plane is very narrow, indicating that the wurtzite InGaN nanorod crystals have high quality. The position of the diffraction peak of the (002) crystal face is positioned at 32.46 degrees, so that the indium composition of the InGaN nanorod is about 65 percent, and higher In doping is realized. FIG. 5 is a photoluminescence spectrum (PL) of the sample of example 1, from which a distinct photoluminescence signal can be observed, and the fluorescence spectrum of InGaN nanorods shows an emission peak at 716 nm. FIG. 6 is a photo-amperometric plot of the sample of example 1 applied to photoelectrochemical water splitting with a photocurrent density of 0.48mA/cm at 1.23V vs. RHE². FIG. 7 is a graph of photocurrent stability at 40min for the sample of example 1, and the result shows that the InGaN nanorods have good stability when used as a photoelectric device.

Example 2: a method for preparing wurtzite InGaN nanorods on a silicon substrate comprises the following specific steps:

(2) Ammoniation treatment of a silicon substrate: the pressure of the ammoniation treatment of the silicon substrate is atmospheric pressure, and 1000sccmnH is introduced when the temperature of the reaction zone is 350 DEG C₃Keeping for 15 min; after treatment, Si-N bonds are formed on the silicon surface, so that the residual stress of the silicon surface is reduced, and the InGaN is easier to nucleate on the silicon surface.

(3) Growing the InGaN nanorods: NH (NH)₃The flow rate was constant. Adjusting N₂The carrier gas flow rate was 500 sccm. Controlling the temperature of the reaction zone to 550 ℃, and heating the InCl₃To 380Heating GaCl at a temperature of₃The growth time is 20min when the temperature is up to 70 ℃.

Example 3: a method for preparing wurtzite InGaN nanorods on a silicon substrate comprises the following specific steps:

(2) Ammoniation treatment of a silicon substrate: the pressure of ammoniation treatment of the silicon substrate is atmospheric pressure, and 1500sccmnH is introduced when the temperature of a reaction zone is 350 DEG C₃Keeping for 25 min; after treatment, Si-N bonds are formed on the silicon surface, so that the residual stress of the silicon surface is reduced, and the InGaN is easier to nucleate on the silicon surface.

(3) Growing the InGaN nanorods: NH (NH)₃The flow rate was constant. Adjusting N₂The carrier gas flow rate was 1000 sccm. Controlling the temperature of the reaction zone to 650 ℃, and heating the InCl₃Heating GaCl to 420 deg.C₃The growth time is 40min when the temperature is up to 80 ℃.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing wurtzite InGaN nanorods on a silicon substrate is characterized in that: firstly, ammoniating the surface of a silicon substrate by ammonia gas, and forming Si-N bonds on the treated silicon surface and Si dangling bonds on the saturated silicon surface; then GaCl3 and InCl3 are conveyed into a reaction chamber with a silicon substrate In an N2 mode, GaCl3 and InCl3 are heated, GaCl3 and InCl3 In a gas phase form Ga and In liquid drops on the surface of the substrate under the action of thermal decomposition and hydrogen reduction, the liquid drops are accumulated to form nuclei, and finally the nuclei react with NH3 In the gas phase to generate wurtzite InGaN.

2. The method of preparing wurtzite InGaN nanorods on silicon substrates according to claim 1, characterized in that: the method comprises the following specific steps:

(1) equipment installation: placing the silicon substrate into a reaction zone of a tube furnace; three small quartz inner tubes with the diameter of 20mm are placed in a quartz outer tube with the diameter of 80mm, wherein the two small quartz inner tubes are arranged above, one small quartz inner tube is arranged below, and the two upper small quartz inner tubes respectively transmit N2 and NH3 into the quartz outer tube; GaCl is placed in the quartz inner tube at the lower part₃And InCl₃Introduction of N₂As InCl₃And GaCl₃The carrier gas of (4); 400-sodium-dodecyl benzene 600sccmN before reaction₂Used for cleaning and diluting reactants, and carrying out reaction under atmospheric pressure;

(2) ammoniation treatment of a silicon substrate: ammoniation treating silicon substrate under atmospheric pressure, introducing 1000-1500sccmnH when the temperature of reaction zone is raised to 350 DEG C₃Keeping for 15min-25 min; forming Si-N bonds on the silicon surface after treatment;

3. The method of preparing wurtzite InGaN nanorods on silicon substrates according to claim 2, characterized in that: the length of the upper small quartz inner tube is 100 mm; the length of the lower quartz inner tube is 1700 mm.