阅读说明：本技术 一种黑硅材料的制备方法 (Preparation method of black silicon material ) 是由 吴立志 张文豪 沈瑞琪 于 2020-05-06 设计创作，主要内容包括：本发明提供了一种黑硅材料的制备方法,具体步骤如下：步骤1,对P型CZ单晶硅片进行切片、清洗、退火、抛光预处理；步骤2,对预处理后的单晶硅片去除损伤层和氧化层。步骤3,对去除损伤层和氧化层的单晶硅片制绒,在抛光硅片表面形成金字塔结构阵列；步骤4,将表面有金字塔结构的单晶硅片中的的硅片置于H-(2)O-(2)、HF和AgNO-(3)的混合溶液刻蚀；步骤5,步骤4将反应后的硅片,置于一定的浓度HNO-(3)溶液中,超声清洗,以去除Ag颗粒,最终得到黑硅材料。(The invention provides a preparation method of a black silicon material, which comprises the following specific steps: step 1, carrying out slicing, cleaning, annealing and polishing pretreatment on a P-type CZ monocrystalline silicon wafer; and 2, removing the damaged layer and the oxide layer of the pretreated monocrystalline silicon wafer. Step 3, texturing the monocrystalline silicon wafer with the damaged layer and the oxide layer removed, and forming a pyramid structure array on the surface of the polished silicon wafer; step 4, placing the silicon wafer in the monocrystalline silicon wafer with the pyramid structure on the surface in the H 2 O 2 HF and AgNO 3 Etching the mixed solution; step 5, step 4, placing the silicon slice after reaction in a certain concentration of HNO 3 And in the solution, carrying out ultrasonic cleaning to remove Ag particles, and finally obtaining the black silicon material.)

1. The preparation method of the black silicon material is characterized by comprising the following specific steps of:

step 1, carrying out slicing, cleaning, annealing and polishing pretreatment on a P-type CZ monocrystalline silicon wafer;

and 2, removing the damaged layer and the oxide layer of the pretreated monocrystalline silicon wafer.

Step 3, texturing the monocrystalline silicon wafer with the damaged layer and the oxide layer removed, and forming a pyramid structure array on the surface of the polished silicon wafer;

step 4, placing the silicon wafer in the monocrystalline silicon wafer with the pyramid structure on the surface in the H₂O₂HF and AgNO₃Etching the mixed solution;

step 5, step 4, placing the silicon slice after reaction in a certain concentration of HNO₃And in the solution, carrying out ultrasonic cleaning to remove Ag particles, and finally obtaining the black silicon material.

2. The method according to claim 1, wherein in step 2, NaOH solution or KOH solution is used for removing the damaged layer; the solution for removing the oxidation layer is HF solution.

3. The preparation method according to claim 2, wherein in the step 2, when NaOH solution is adopted, the concentration of the solution is 3.0-4.0 mol/L, the temperature is 85-90 ℃, and the time is 5-12 min; when a KOH solution is adopted, the concentration of the solution is 3.0-4.0 mol/L, the temperature is 85-90 ℃, and the time is 5-12 min; when the HF solution is adopted, the concentration of the solution is 0.8-1.2 mol/L, the temperature is 20-30 ℃, and the time is 5-8 min.

4. The method according to claim 1, wherein in step 3, a NaOH + IPA solution, a KOH + IPA solution, or a TMAH + IPA solution system is used to texture the single crystal silicon wafer for removing the damaged layer and the oxide layer.

5. The preparation method according to claim 1, wherein when NaOH + IPA solution is used in step 3, the concentration of the NaOH solution is 0.5-0.75 mol/L, the volume fraction of the isopropanol solution is 5%, the temperature is 85-90 ℃, and the time is 30-35 min; when a KOH + IPA solution is adopted, the concentration of the NaOH solution is 0.5-0.75 mol/L, the volume fraction of the isopropanol solution is 5%, the temperature is 85-90 ℃, and the time is 30-35 min; when TMAH + IPA solution is adopted, the concentration of the TMAH solution is 0.6-0.8 mol/L, the volume fraction of the isopropyl alcohol solution is 5%, the temperature is 85-90 ℃, and the time is 35-45 min.

6. The method according to claim 1, wherein in step 4, H is₂O₂The concentration of (A) is 4.4-4.8 mol/L, the concentration of HF is 0.4-0.6 mol/L, AgNO₃The concentration of the components is 0.2-0.6 mmol/L, the volume ratio is 1:1:1, the temperature is 30-35 ℃, and the time is 2-5 min.

7. The preparation method according to claim 1, wherein in the step 5, the concentration of the HNO3 solution is 30-40 vol%, the temperature is 30-35 ℃, and the time is 2-4 min.

Technical Field

The invention relates to a photoelectric material technology, in particular to a preparation method of a black silicon material.

Background

In the 90 s of the 20 th century, professor Mazur of Harvard university in USA and the like, high-energy irradiation is carried out on the surface of a silicon wafer by high-intensity ultrashort pulse laser generated by a femtosecond laser under the atmosphere of SF6 gas, the lower surface of the obtained silicon wafer is black on naked eyes, namely 'black silicon', and the absorption rate of a prepared sample to visible light can reach more than 90%. The emergence of the black silicon material enables the silicon material to have breakthrough application in the fields of photoelectric detection, optical communication, photovoltaic cells and the like.

At present, researches on the preparation of the black silicon have achieved great results, and mainly include a reactive ion etching method, a chemical etching method, an electrochemical etching method and a femtosecond laser method, wherein the reactive ion etching method and the femtosecond laser method have the prominent problems that experimental equipment is expensive, large-area black silicon is difficult to prepare, and the large-area black silicon is not suitable for large-scale industrial production, and although the electrochemical etching method is low in cost, the prepared porous structure is not uniform, and the large-area black silicon is difficult to prepare. Therefore, there is a need for a low-cost, large-scale industrial process.

Disclosure of Invention

The invention aims to provide a preparation method of a black silicon material.

The technical scheme for realizing the purpose of the invention is as follows: a preparation method of a black silicon material comprises the following specific steps:

step 1, carrying out slicing, cleaning, annealing and polishing pretreatment on a P-type CZ monocrystalline silicon wafer;

and 2, removing the damaged layer and the oxide layer of the pretreated monocrystalline silicon wafer.

Step 3, texturing the monocrystalline silicon wafer with the damaged layer and the oxide layer removed, and forming a pyramid structure array on the surface of the polished silicon wafer;

step 4, placing the silicon wafer in the monocrystalline silicon wafer with the pyramid structure on the surface in the H₂O₂HF and AgNO₃Etching the mixed solution;

step 5, step 4, placing the silicon slice after reaction in a certain concentration of HNO₃And in the solution, carrying out ultrasonic cleaning to remove Ag particles, and finally obtaining the black silicon material.

Further, in the step 2, NaOH solution and KOH solution are adopted for removing the damage layer; the solution of the deoxidation layer is an HF solution.

Further, in the step 2, when a NaOH solution is adopted, the concentration of the solution is 3.0-4.0 mol/L, the temperature is 85-90 ℃, and the time is 5-12 min; when a KOH solution is adopted, the concentration of the solution is 3.0-4.0 mol/L, the temperature is 85-90 ℃, and the time is 5-12 min; when the HF solution is adopted, the concentration of the solution is 0.8-1.2 mol/L, the temperature is 20-30 ℃, and the time is 5-8 min.

Furthermore, in step 3, a NaOH + IPA solution, a KOH + IPA solution, and a TMAH + IPA solution system are adopted to texture the monocrystalline silicon wafer from which the damaged layer and the oxide layer are removed.

Further, when NaOH + IPA solution is adopted in the step 3, the concentration of the NaOH solution is 0.5-0.75 mol/L, the volume fraction of the isopropanol solution is 5%, the temperature is 85-90 ℃, and the time is 30-35 min; when KOH + IPA solution is adopted, the concentration of NaOH solution is 0.5-0.75 mol/L, the volume fraction of isopropanol solution is 5%, the temperature is 85-90 ℃, and the time is 30-35 min; when TMAH + IPA solution is adopted, the concentration of the TMAH solution is 0.6-0.8 mol/L, the volume fraction of the isopropyl alcohol solution is 5%, the temperature is 85-90 ℃, and the time is 35-45 min.

Further, in step 4, H₂O₂The concentration of (A) is 4.4-4.8 mol/L, the concentration of HF is 0.4-0.6 mol/L, AgNO₃The concentration of the components is 0.2-0.6 mmol/L, the volume ratio is 1:1:1, the temperature is 30-35 ℃, and the time is 2-5 min.

Further, in the step 5, the concentration of the HNO3 solution is 30-40 vol%, the temperature is 30-35 ℃, and the time is 2-4 min.

Compared with the prior art, the invention has the remarkable advantages that: (1) according to the invention, the traditional alkaline solution is adopted to texture the monocrystalline silicon piece, the reaction is controllable, the device is simple, and a catalyst is not required; (2) the invention adopts H₂O₂HF and AgNO₃The mixed solution etching has controllable reaction and low cost, does not need expensive experimental equipment, and can meet the requirement of large-scale production; (3) the average reflectivity of the black silicon material prepared by the invention in the visible light wave band range (900 nm-1700 nm) is 11.6%, and the laser absorption rate is greatly improved.

The invention is further described below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic flow chart of the process for preparing "black silicon" according to the present invention.

FIG. 2 is a surface SEM image of "black silicon" material prepared in example 1.

Detailed Description

With reference to fig. 1, the preparation method of the present invention has the following process flow:

step 1, selecting a P-type (CZ) monocrystalline silicon wafer with the thickness of 0.50mm, and carrying out pretreatment. The process mainly comprises the steps of slicing, cleaning, annealing and polishing the silicon wafer.

Step 2, removing a damaged layer of the pretreated monocrystalline silicon wafer, and adopting NaOH solution with the concentration of 3.0-4.0 mol/L, wherein the temperature is 85-90 ℃, and the time is 5-12 min; or 3.0-4.0 mol/L KOH solution is adopted, the temperature is 85-90 ℃, the time is 5-12 min, and the time is 10-20 min; and then removing the oxide layer, and adopting an HF solution with the concentration of 0.8-1.2 mol/L, wherein the temperature is 20-30 ℃, and the time is 5-8 min.

Step 3, texturing the monocrystalline silicon wafer with the damage layer and the oxide layer removed, wherein when NaOH + IPA solution is adopted, the concentration of the NaOH solution is 0.5-0.75 mol/L, the volume fraction of the isopropyl alcohol solution is 5%, the temperature is 85-90 ℃, and the time is 30-35 min; when a KOH + IPA solution is adopted, the concentration of the NaOH solution is 0.5-0.75 mol/L, the volume fraction of the isopropanol solution is 5%, the temperature is 85-90 ℃, and the time is 30-35 min; when TMAH + IPA solution is adopted, the concentration of the TMAH solution is 0.6-0.8 mol/L, the volume fraction of the isopropyl alcohol solution is 5%, the temperature is 85-90 ℃, and the time is 35-45 min.

Step 4, placing the silicon wafer in the monocrystalline silicon wafer with the pyramid structure on the surface in the H₂O₂HF and AgNO₃Etching with the mixed solution of (1). H₂O₂The concentration of (A) is 4.4-4.8 mol/L, the concentration of HF is 0.4-0.6 mol/L, AgNO₃The concentration of (A) is 0.2-0.6 mmol/L, and the components are mixed according to the volume ratio of 1:1:1, the temperature is 30-35 ℃, and the time is 2-5 min.

And 5, placing the reacted silicon wafer in 30-40 vol% of HNO3 solution at the temperature of 30-35 ℃ for 2-4 min, and ultrasonically cleaning to remove Ag particles, so as to obtain the black silicon material.

Example 1

The preparation method of the anti-reflection micro-nano structure material comprises the following steps:

step 1, selecting a P-type (CZ) monocrystalline silicon wafer with the thickness of 0.50mm, and carrying out pretreatment. The process mainly comprises the steps of slicing, cleaning, annealing and polishing the silicon wafer.

Step 2, removing a damage layer of the pretreated monocrystalline silicon wafer, and adopting NaOH solution with the concentration of 3.0mol/L, wherein the temperature is 90 ℃ and the time is 10 min; then removing an oxide layer, adopting an HF solution with the concentration of 1.0mol/L, and keeping the temperature at 25 ℃ for 8 min;

step 3, texturing the monocrystalline silicon wafer with the damaged layer and the oxide layer removed, wherein a NaOH + IPA solution is adopted, the concentration of the NaOH solution is 0.5mol/L, the volume fraction of the IPA solution is 5%, and the temperature is 90 ℃ for 30 min;

step 4, placing the silicon wafer in the monocrystalline silicon wafer with the pyramid structure on the surface in the H₂O₂HF and AgNO₃Etching with the mixed solution of (1). H₂O₂Has a concentration of 4.4mol/L, a concentration of HF of 0.4mol/L, AgNO₃The concentration of (A) is 0.2mmol/L, the volume ratio is 1:1:1, the temperature is 32 ℃, and the time is 3 min;

and 5, placing the reacted silicon wafer in a 30 vol% HNO3 solution at 35 ℃ for 3min by ultrasonic cleaning to remove Ag particles, and finally forming the black silicon material. The SEM of the resulting product is shown in FIG. 2.

Comparative example 1

This comparative example was conducted only to step (three), and the cross-sectional view of the resulting product is shown in FIG. 2.

It can be seen from fig. 2 that the pyramid-pit structure obtained in example 1 greatly improves the laser absorption rate. As can be seen from fig. 2, the structure of the pyramid formed on the surface of the single crystal silicon is shown. The sample of example 1 has an average reflectance of 11.2% in the near infrared band (900nm to 1700nm), whereas the sample of comparative example 1 has an average reflectance of 21.4% in the near infrared band (900nm to 1700nm), and the sample of example 1 has a better antireflection effect, in comparison.