Perovskite single-mode laser based on aluminum oxide surface passivation layer and preparation method thereof

Abstract

The invention relates to the technical field of optoelectronic devices, in particular to a perovskite single-mode laser based on an aluminum oxide surface passivation layer and a preparation method thereof.The preparation method comprises the steps that S1, a high-purity silicon wafer is selected as a substrate layer, and a silicon dioxide layer is deposited on the surface of the high-purity silicon wafer; and S3, putting the substrate into a beaker filled with a dichloromethane solution, covering the beaker with a tin foil, putting the beaker into an incubator, and completely evaporating the dichloromethane solution to obtain the perovskite microcavity arranged on the surface of the silicon dioxide layer, s4, an aluminum oxide layer is deposited on the surface of the perovskite microcavity through the atomic deposition technology to serve as a passivation layer; the CsPbBr3 perovskite single-mode laser based on the Al2O3 surface passivation layer not only has high stability, but also realizes remarkable improvement on the laser performance.

Description

Technical Field

[0001] The invention relates to the technical field of optoelectronic devices, and in particular to a perovskite single-mode laser based on an aluminum oxide surface passivation layer and a preparation method thereof. Background Art

[0002] Perovskite materials show great potential in the field of semiconductor microcavity lasers due to their excellent optoelectronic properties. However, the surface defects and instability of perovskite materials limit their application in high-performance lasers.

[0003] The Chinese patent publication number: CN111313238A discloses a conical perovskite micro-nanocrystalline laser and a preparation method thereof; the method is implemented by a solution method, comprising the following steps: (1) adding lead halide and methylammonium halide to a solvent, mixing them evenly, and obtaining a perovskite precursor solution; (2) dripping the perovskite precursor solution in step (1) onto a substrate containing a perovskite material variety, and obtaining a substrate after dripping; (3) placing the substrate after dripping in step (2) in an anti-solvent gas environment, and allowing the anti-solvent to diffuse into the dripped precursor solution to cause crystallization, and waiting for the substrate to drip. After the solvent evaporates, the conical perovskite micro-nano crystal body obtained on the substrate is the conical perovskite micro-nano crystal laser; the preparation method described in the present invention uses simple equipment and devices, is fast and convenient, simple to operate, low cost, very high repeatability, good morphology, and has excellent laser behavior. The higher purity micro-nano crystals improve the various performances of the semiconductor laser; it can be seen that the conical perovskite micro-nano crystal laser and its preparation method have the following problems: the laser is limited by the surface defects and instability of the material itself, and these factors seriously affect the luminous efficiency and stability of the laser. Summary of the invention

[0004] To this end, the present invention provides a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer and a preparation method thereof, so as to overcome the problems of poor luminous efficiency and stability of laser materials in the prior art.

[0005] To achieve the above object, the present invention provides a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer, comprising:

[0006] A base layer, wherein the base layer is a silicon wafer;

[0007] A silicon dioxide layer, wherein the silicon dioxide layer is disposed on the surface of the substrate layer;

[0008] A perovskite microcavity, wherein the perovskite microcavity is disposed on the surface of the silicon dioxide layer, and the perovskite microcavity is composed of a CsPbBr3 perovskite layer;

[0009] The passivation layer is made of aluminum oxide and deposited on the surface of the perovskite microcavity.

[0010] Furthermore, the silicon dioxide layer is deposited on the upper surface of the base layer, the perovskite microcavity is arranged on the upper surface of the silicon dioxide layer, and the passivation layer completely covers the outer surface of the perovskite microcavity.

[0011] Furthermore, the thickness H1 of the silicon wafer is set to 1 mm;

[0012] The thickness H2 of the silicon dioxide layer is set to 3 nm;

[0013] The thickness H3 of the perovskite microcavity is set to satisfy 0.9 μm≤H3≤1.1 μm;

[0014] The thickness H4 of the passivation layer is set to satisfy 5nm≤H4≤20nm.

[0015] The present invention provides a method for preparing a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer, comprising the following steps:

[0016] Step S1, selecting a high-purity silicon wafer as a base layer, cleaning the surface of the base layer, depositing a silicon dioxide layer on the surface of the high-purity silicon wafer, and cleaning the surface of the silicon dioxide layer;

[0017] Step S2, preparing CsBr powder, PbBr2 powder, and dimethyl sulfoxide, dissolving the CsBr powder and the PbBr2 powder in dimethyl sulfoxide to obtain a precursor solution, and drop-casting the precursor solution on the surface of the silicon dioxide layer in step S1 to obtain a substrate;

[0018] Step S3, preparing a beaker with a built-in platform, the beaker is filled with dichloromethane liquid, the liquid level of the dichloromethane liquid is 3 cm away from the built-in platform, placing the substrate on the built-in platform, and covering the beaker with tin foil, placing the tin foil-covered beaker in an incubator to completely evaporate the dichloromethane liquid, thereby obtaining a perovskite microcavity disposed on the surface of the silicon dioxide layer;

[0019] Step S4, using atomic deposition technology to deposit a layer of aluminum oxide as a passivation layer on the surface of the perovskite microcavity in step S2.

[0020] Furthermore, in step S1, the silicon dioxide layer is deposited on the surface of the high-purity silicon wafer by a thermal oxidation method.

[0021] Further, in step S2, the CsBr powder is 0.25 mmol, the PbBr2 powder is 0.25 mmol, and the dimethyl sulfoxide is 5 ml.

[0022] Further, in step S3, the temperature of the incubator is set to 60°C.

[0023] Furthermore, in step S4, the thickness H4 of the passivation layer satisfies 5nm≤H4≤20nm, and the thickness of the passivation layer is precisely controlled by precisely controlling the number of cycles of the atomic deposition technology.

[0024] Furthermore, in step S2, the amount of CsBr powder, the amount of PbBr2 powder, and the amount of dimethyl sulfoxide are controlled to change the concentration of the precursor solution to optimize the growth of perovskite crystals and obtain high-quality perovskite microcavities.

[0025] Further, in step S3, the growth of perovskite crystals is optimized by adjusting the temperature of the incubator to obtain high-quality perovskite microcavities.

[0026] Compared with the prior art, the beneficial effect of the present invention lies in that, by introducing a carefully designed Al2O3 passivation layer on the surface of the perovskite microcavity, the present invention effectively reduces surface defects, thereby significantly improving the optical performance of the device. The CsPbBr3 perovskite single-mode laser based on the Al2O3 surface passivation layer not only has high stability, but also achieves a significant improvement in laser performance. The CsPbBr3 perovskite single-mode laser based on the Al2O3 surface passivation layer can emit single-mode laser at a lower excitation threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of the CsPbBr3 perovskite single-mode laser based on the Al2O3 surface passivation layer of this embodiment;

[0028] Figure 2 This is a flow chart of the preparation method of the CsPbBr3 perovskite single-mode laser based on the Al2O3 surface passivation layer of this embodiment;

[0029] Figure 3 The fluorescence spectra and microcavity lasing threshold comparison diagrams of this embodiment and the prior art at different excitation powers. DETAILED DESCRIPTION

[0030] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0032] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0033] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] See also Figure 1 As shown, it is a schematic structural diagram of a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer in this embodiment. The CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer includes:

[0035] A base layer 1, wherein the base layer 1 is a silicon wafer;

[0036] A silicon dioxide layer 2, wherein the silicon dioxide layer 2 is disposed on the surface of the base layer 1;

[0037] A perovskite microcavity 3, wherein the perovskite microcavity 3 is disposed on the surface of the silicon dioxide layer 2, and the perovskite microcavity 3 is composed of a CsPbBr3 perovskite layer;

[0038] The passivation layer 4 is made of aluminum oxide and deposited on the surface of the perovskite microcavity 3 .

[0039] Specifically, by adding a passivation layer composed of aluminum oxide to the surface of the perovskite microcavity, the surface defects of the perovskite microcavity are effectively reduced, the stability and performance of the device are improved, and a single-mode laser with high stability and excellent optoelectronic properties is achieved.

[0040] Specifically, the silicon dioxide layer 2 is deposited on the upper surface of the base layer 1 , the perovskite microcavity 3 is arranged on the upper surface of the silicon dioxide layer 2 , and the passivation layer 4 completely covers the outer surface of the perovskite microcavity 4 .

[0041] Specifically, by completely covering the outer surface of the perovskite microcavity 3 with the passivation layer 4, the surface defects of the entire perovskite microcavity are reduced to a certain extent, thereby lowering the excitation threshold of the sPbBr3 perovskite single-mode laser.

[0042] Specifically, the thickness H1 of the silicon wafer is set to 1 mm;

[0043] The thickness H2 of the silicon dioxide layer 2 is set to 3 nm;

[0044] The thickness H3 of the perovskite microcavity 3 is set to satisfy 0.9 μm≤H3≤1.1 μm;

[0045] The thickness H4 of the passivation layer 4 is set to satisfy 5nm≤H4≤20nm.

[0046] See also Figure 2 As shown, it is a schematic flow chart of a method for preparing a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer in this embodiment, and the method includes:

[0047] Step S1, purchasing a high-purity silicon wafer with a 3 nm silicon dioxide layer on the surface as a base layer, and cleaning the surface of the base layer using ether, alcohol, acetone, oxygen plasma, etc.;

[0048] Step S2, preparing CsBr powder, PbBr2 powder, and dimethyl sulfoxide, dissolving the CsBr powder and the PbBr2 powder in dimethyl sulfoxide to obtain a precursor solution, and using a pipette to spin-coat 5-20 μL of the precursor solution on the surface of the silicon dioxide layer in step S1 to obtain a substrate;

[0049] Step S3, preparing a beaker with a built-in platform, the beaker is filled with dichloromethane liquid, the liquid level of the dichloromethane liquid is 3 cm away from the built-in platform, placing the substrate on the built-in platform, and covering the beaker with tin foil, placing the tin foil-covered beaker in an incubator to completely evaporate the dichloromethane liquid, thereby obtaining a perovskite microcavity disposed on the surface of the silicon dioxide layer;

[0050] Step S4, using atomic layer deposition technology to deposit an aluminum oxide interface layer, the specific steps are: install trimethylaluminum (Al(CH3)3) and water (H2O) sources in the ALD deposition system in advance, and set the chamber temperature to 80-100°C. Under vacuum and 80-100°C, using Al(CH3)3 and H2O to alternately react, deposit Al2O3 with a thickness of 5-20nm on the surface of the perovskite microcavity in step S3 at a rate of 0.1nm / cyc le as a passivation layer, and cool for 5 minutes after completion.

[0051] Specifically, the high-purity silicon wafer refers to a silicon wafer with a purity of 5N or above, that is, a silicon wafer with a purity of 99.999% or above; the precursor solution refers to a compound solution containing specific elements, which can be converted into the desired semiconductor material through chemical reaction. In this embodiment, the precursor solution is obtained by dissolving CsBr powder and PbBr2 powder in dimethyl sulfoxide; the substrate is a high-purity silicon wafer with a 3nm silicon dioxide layer on the surface, and the precursor solution is spin-coated on the surface of the silicon dioxide layer; the atomic layer deposition technology is a thin film deposition technology based on surface self-limiting reaction, which constructs atomic-level thin films layer by layer on the substrate surface by alternately introducing two precursors into the reaction chamber and utilizing chemical adsorption and reaction; the perovskite microcavity is a micro-optical resonant cavity constructed based on perovskite material, and the passivation layer is a thin film layer formed on the surface of the material, the main purpose of which is to improve the corrosion resistance, stability and photoelectric properties of the perovskite microcavity.

[0052] Specifically, in step S1, the selected substrate is a high-purity silicon wafer, and a 3 nm thick silicon dioxide layer is generated by in-situ reaction on the surface of the silicon wafer using a thermal oxidation method.

[0053] Specifically, in step S2, the CsBr powder is 0.25-0.5 mmol, the PbBr2 powder is 0.25-0.5 mmol, and the dimethyl sulfoxide is 5-10 ml.

[0054] Specifically, in step S3, the temperature of the incubator is set to 30-70°C.

[0055] Specifically, in step S4, the thickness H4 of the passivation layer satisfies 5nm≤H4≤20nm, and the thickness of the passivation layer is precisely controlled by precisely controlling the number of cycles of the atomic deposition technology. The specific steps are: install the sources of trimethylaluminum (Al(CH3)3) and water (H2O) in the ALD deposition system in advance, and set the chamber temperature to 80-100°C. Al(CH3)3 and H2O are used for alternating reactions under vacuum and 80-100°C, the number of cycles is controlled to be 50-200 times, and the deposition rate is 0.1nm / cyc le. In step S3, Al2O3 with a thickness of 5-20nm is deposited on the surface of the perovskite microcavity as a passivation layer, and then cooled for 5 minutes for standby use.

[0056] Specifically, in step S2, the amount of CsBr powder is controlled to be 0.25-0.5 mmol, the amount of PbBr2 powder is controlled to be 0.25-0.5 mmol, and the amount of dimethyl sulfoxide is controlled to be 5-10 ml. Equimolar amounts of CsBr and PbBr2 powders are added to 5-10 ml of dimethyl sulfoxide in a ratio of 1:1 to obtain a precursor solution. The concentration of the precursor solution is adjusted by changing the solvent volume of dimethyl sulfoxide by 5-10 ml.

[0057] Specifically, in step S3, the temperature of the incubator is adjusted to a range of 30-70°C to optimize the growth of perovskite crystals to obtain high-quality perovskite microcavities. Specifically, the incubator temperature variable is first controlled to be 30°C, and the concentration of the precursor solution is adjusted by changing the solvent volume of dimethyl sulfoxide by 5-10ml, and the perovskite microcavity is grown using the reaction device described in step S3. After the dichloromethane liquid in the device is completely evaporated, a perovskite microcavity disposed on the surface of the silicon dioxide layer is obtained. The surface morphology and roughness changes of the perovskite microcavity are observed using a scanning electron microscope and an atomic force microscope, and a perovskite microcavity with a flat and smooth surface is preferably selected, and the concentration of the precursor solution under the corresponding growth conditions is recorded as 0.3mmo l. Then the concentration of the precursor solution is fixed to 0.3mmo l, the incubator temperature variable is adjusted to a range of 30-70°C, and the perovskite microcavity is grown using the reaction device described in step S3. After the dichloromethane liquid in the device is completely evaporated, a perovskite microcavity disposed on the surface of the silicon dioxide layer is obtained. The surface morphology and roughness of the perovskite microcavity were observed using a scanning electron microscope and an atomic force microscope, and the perovskite microcavity with a flat and smooth surface was selected, and the growth temperature under the corresponding growth conditions was recorded as 60°C. Therefore, the concentration of the optimized precursor solution is 0.3 mmol l, and the growth temperature of the incubator is 60°C. According to this growth condition, high-quality perovskite microcavity can be obtained.

[0058] See also Figure 3 As shown in the figure, the fluorescence spectrum and lasing threshold curve of the device are compared with the excitation power, where (a) is the fluorescence spectrum change of the CsPbBr3 perovskite microcavity near the lasing threshold, and (b) is the lasing threshold curve of the CsPbBr3 microcavity; (c) is the fluorescence spectrum change of the Al2O3-CsPbBr3 perovskite microcavity near the lasing threshold, and (d) is the lasing threshold curve of the Al2O3-CsPbBr3 microcavity. By comparison, it can be found that the lasing threshold of the CsPbBr3 perovskite single-mode laser is 63 microjoules / cubic centimeter, while the lasing threshold of the Al2O3-CsPbBr3 perovskite single-mode laser drops to 31 microjoules / cubic centimeter. This shows that compared with the CsPbBr3 perovskite microcavity, the Al2O3-CsPbBr3 microcavity has better laser performance.

[0059] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer, characterized in that: include, A base layer, wherein the base layer is a silicon wafer; A silicon dioxide layer, wherein the silicon dioxide layer is disposed on the surface of the substrate layer; A perovskite microcavity, wherein the perovskite microcavity is disposed on the surface of the silicon dioxide layer, and the perovskite microcavity is composed of a CsPbBr3 perovskite layer; The passivation layer is made of aluminum oxide and deposited on the surface of the perovskite microcavity.

2. The CsPbBr3 perovskite single-mode laser based on Al2O3 surface passivation layer according to claim 1, characterized in that: The silicon dioxide layer is deposited on the upper surface of the base layer, the perovskite microcavity is arranged on the upper surface of the silicon dioxide layer, and the passivation layer completely covers the outer surface of the perovskite microcavity.

3. The CsPbBr3 perovskite single-mode laser based on Al2O3 surface passivation layer according to claim 1, characterized in that: The thickness H1 of the silicon wafer is set to 1 mm; The thickness H2 of the silicon dioxide layer is set to 3 nm; The thickness H3 of the perovskite microcavity is set to satisfy 0.9 μm≤H3≤1.1 μm; The thickness H4 of the passivation layer is set to satisfy 5nm≤H4≤20nm.

4. The method for preparing a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer according to claims 1 to 3, characterized in that: The following steps are involved: Step S1, selecting a high-purity silicon wafer as a base layer, cleaning the surface of the base layer, depositing a silicon dioxide layer on the surface of the high-purity silicon wafer, and cleaning the surface of the silicon dioxide layer; Step S2, preparing CsBr powder, PbBr2 powder, and dimethyl sulfoxide, dissolving the CsBr powder and the PbBr2 powder in dimethyl sulfoxide to obtain a precursor solution, and drop-casting the precursor solution on the surface of the silicon dioxide layer in step S1 to obtain a substrate; Step S3, preparing a beaker with a built-in platform, the beaker is filled with dichloromethane liquid, the liquid level of the dichloromethane liquid is 3 cm away from the built-in platform, placing the substrate on the built-in platform, and covering the beaker with tin foil, placing the tin foil-covered beaker in an incubator to completely evaporate the dichloromethane liquid, thereby obtaining a perovskite microcavity disposed on the surface of the silicon dioxide layer; Step S4, using atomic deposition technology to deposit a layer of aluminum oxide as a passivation layer on the surface of the perovskite microcavity in step S2.

5. The method for preparing a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer according to claim 4, characterized in that: In step S1, the silicon dioxide layer is deposited on the surface of the high-purity silicon wafer by a thermal oxidation method.

6. The method for preparing a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer according to claim 4, characterized in that: In step S2, the CsBr powder is 0.25 mmol, the PbBr2 powder is 0.25 mmol, and the dimethyl sulfoxide is 5 ml.

7. The method for preparing a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer according to claim 4, characterized in that: In step S3, the temperature of the incubator is set to 60°C.

8. The method for preparing a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer according to claim 4, characterized in that: In step S4, the thickness H4 of the passivation layer satisfies 5nm≤H4≤20nm. The thickness of the passivation layer is precisely controlled by precisely controlling the number of cycles of the atomic deposition technology.

9. The method for preparing a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer according to claim 4, characterized in that: In step S2, the amount of CsBr powder, the amount of PbBr2 powder, and the amount of dimethyl sulfoxide are controlled to change the concentration of the precursor solution to optimize the growth of perovskite crystals and obtain high-quality perovskite microcavities.

10. The method for preparing a CsPbBr3 perovskite single-mode laser based on an Al2O3 surface passivation layer according to claim 4, characterized in that: In step S3, the growth of perovskite crystals is optimized by adjusting the temperature of the incubator to obtain high-quality perovskite microcavities.

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