Low-noise perovskite optoelectronic device and preparation method thereof

Abstract

The invention discloses a low-noise perovskite optoelectronic device. The low-noise perovskite optoelectronic device comprises a first metal electrode, a perovskite layer and a second metal electrode, the first metal electrodes are respectively evaporated on the upper surface and the lower surface of the perovskite layer; the second metal electrode is an annular electrode prepared on the surface of the first metal electrode, and the second metal electrode is surrounded in the first metal electrode and used for preventing transverse diffusion of charges of the first metal electrode. The low-noise perovskite optoelectronic device prepared by the invention can effectively form a uniform electric field and reduce transverse diffusion of current on the surface and in the body, so that the efficiency of the device is improved and the noise is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite solar cells, and more specifically, relates to a low-noise perovskite optoelectronic device and a preparation method thereof. Background Art

[0002] Noise includes thermal noise, shot noise, and 1 / f noise. These noise problems seriously affect the optoelectronic properties of optoelectronic devices, such as dark current, sensitivity, short-circuit current, and open-circuit voltage. In particular, low-frequency 1 / f noise can be observed in various fields such as music, meteorology, biology, electronic materials and devices, and has a wide range of occurrence.

[0003] Organic-inorganic metal halide perovskite materials are a type of semiconductor material with excellent performance, which has triggered a research boom in recent years. In the fields of solar cells, light-emitting diodes, X-ray detection, etc., they have shown performance close to or exceeding that of traditional semiconductor materials. However, during the preparation process of this type of material, defects are inevitable. The large number of defects leads to a large resistance of the material. Therefore, in the test of its optoelectronic performance, the noise has a particularly large impact on this type of device, resulting in poor performance parameters such as device sensitivity and inaccurate measurement.

[0004] There is currently little research on this issue because it is necessary to find ways to reduce noise in perovskite optoelectronic devices to solve this problem. Summary of the invention

[0005] In view of at least one defect or improvement need of the prior art, the present invention provides a low-noise perovskite optoelectronic device and a method for preparing the same. The present invention is based on reducing the noise, especially the 1 / f noise, in the perovskite optoelectronic device, and proposes a simple and effective method for suppressing and reducing the 1 / f noise in the perovskite optoelectronic device from the perspective of surface passivation of the material, structural design of the device, and design of the surface ring metal electrode and other preparation methods, which effectively reduces the noise problem in the perovskite optoelectronic device and improves the device's sensitivity, dark current and other optoelectronic properties.

[0006] To achieve the above object, according to one aspect of the present invention, a low-noise perovskite optoelectronic device is provided, the perovskite optoelectronic device comprising a first metal electrode, a perovskite layer, and a second metal electrode;

[0007] The first metal electrodes are respectively deposited on the upper and lower surfaces of the perovskite layer;

[0008] The second metal electrode is a ring-shaped electrode prepared on the surface of the first metal electrode. The second metal electrode is surrounded by the first metal electrode to prevent the lateral diffusion of the charge of the first metal electrode.

[0009] Preferably, the perovskite layer is an organic-inorganic composite perovskite single crystal with an ABX3 molecular structure.

[0010] Preferably, the perovskite layer is CsPbBr I3, CH3NH3PbI3 (MAPb3), CH3NH3PbBr3, FAPbBr3, PEABr and FA 1-x Cs x Any one of PbBr3(x=0.05,0.1).

[0011] Preferably, the perovskite layer is passivated with a strong acid solution.

[0012] Preferably, the second metal electrode is any one of Au, Ag, Al, Bi, C, Pb, and ITO.

[0013] According to another aspect of the present invention, there is also provided a method for preparing a low-noise perovskite optoelectronic device, comprising the following steps:

[0014] S1: Preparation of perovskite single crystals and passivation of their surfaces;

[0015] S2: evaporating a first metal electrode on the upper and lower surfaces of the passivated perovskite single crystal;

[0016] S3: preparing ring-shaped electrodes on the surface of the first metal electrode respectively, so that the ring-shaped electrodes are surrounded by the inside of the first metal electrode.

[0017] Preferably, the passivation treatment includes:

[0018] A strong acid solvent is used to passivate the surface of the perovskite single crystal. The strong acid solvent is an acid containing a halogen element, and the halogen element is the same as the halogen element of the perovskite single crystal.

[0019] Preferably, the preparation of the ring-shaped electrode includes cutting the first metal electrode using a laser to form a continuous electrode in a circular ring.

[0020] According to another aspect of the present invention, there is also provided an application of any of the above methods in preparing a low-noise perovskite optoelectronic device.

[0021] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0022] The present invention provides a low-noise perovskite optoelectronic device and a preparation method thereof. The perovskite layer is passivated to effectively passivate the surface defects of the perovskite single crystal, and then annular metal electrodes are evaporated on the upper and lower surfaces thereof respectively. The annular metal electrodes can effectively form a uniform electric field, reduce the lateral diffusion of current on the surface and in the body, thereby improving the efficiency of the device and reducing noise. Not only the lateral expansion of the charge on the surface of the perovskite single crystal is effectively reduced, but also the lateral expansion of the charge inside the single crystal can be reduced, thereby improving the efficiency of the device and reducing noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a physical picture of a perovskite single crystal before passivation prepared in an embodiment of the present invention;

[0024] Figure 2 is a physical picture of the passivated perovskite single crystal prepared in an embodiment of the present invention;

[0025] Figure 3 This is a real picture of a low-noise perovskite optoelectronic device prepared in an embodiment of the present invention;

[0026] Figure 4 This is a comparison chart of the current performance test of the perovskite crystal prepared in the embodiment of the present invention without surface treatment and after passivation treatment;

[0027] Figure 5 These are the noise test results of the power spectrum density without and with the circular ring electrode prepared in the embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] Figure 1 is a schematic diagram of a low-noise perovskite optoelectronic device provided by the present invention, such as Figure 1 As shown, a low-noise perovskite optoelectronic device prepared by the present invention comprises:

[0034] A first metal electrode, a perovskite layer, and a second metal electrode;

[0035] The first metal electrodes are respectively deposited on the upper and lower surfaces of the perovskite layer;

[0036] The second metal electrode is a ring-shaped electrode prepared on the surface of the first metal electrode. The second metal electrode is surrounded by the first metal electrode to prevent the lateral diffusion of the charge of the first metal electrode.

[0037] The present invention also provides a method for preparing a low-noise perovskite optoelectronic device, comprising the following steps:

[0038] S1: Prepare perovskite single crystal and passivate its surface; Figure 2The figure shows the actual perovskite single crystal before passivation. Figure 3 The figure shows a physical picture of the passivated perovskite single crystal. Since there are many defects on the surface of the prepared perovskite single crystal, these defects seriously affect the improvement of device efficiency and are also prone to noise, so the surface of the perovskite single crystal needs to be passivated first. Preferably, a strong acid solvent is used to passivate the surface of the perovskite single crystal, and the strong acid solvent is an acid containing a halogen element, and the halogen element is the same as the halogen element of the perovskite single crystal. For example: hydrobromic acid (HBr) can be used for CsPbBr3 surface passivation, and hydroiodic acid (HI) can be used for CH3NH3PbI3 surface passivation.

[0039] S2: Evaporating a first metal electrode on the upper and lower surfaces of the passivated perovskite single crystal; preferably, the first metal electrode that can be selected includes Au, Ag, Al, Bi, C, Pb, ITO, etc.

[0040] S3: preparing ring-shaped electrodes on the surface of the first metal electrode respectively, so that the ring-shaped electrodes are surrounded by the inside of the first metal electrode.

[0041] After the first metal electrode of the perovskite single crystal is evaporated, a built-in electric field will be formed. The built-in electric field has a lateral diffusion effect on the charges on the surface and in the body. On the one hand, these diffusions lead to charge loss and affect the efficiency of the device, and on the other hand, they also increase the noise. A ring-shaped metal electrode is prepared on the upper and lower surfaces of the perovskite single crystal on which the metal electrode is evaporated. The ring electrode can effectively form a uniform electric field and reduce the lateral diffusion of the current on the surface and in the body, thereby improving the efficiency of the device and reducing the noise. Preferably, the preparation of the ring-shaped metal electrode is as follows: the first metal electrode is cut using a laser of a certain power, the width and depth of the cut electrode must be appropriate, and a continuous electrode in a circular ring must be formed.

[0042] The method for preparing a two-dimensional / three-dimensional heterostructure perovskite layer of the present invention is further illustrated below by means of specific examples.

[0043] Example 1

[0044] Step 1: Prepare perovskite single crystal and passivate its surface

[0045] Preparation Weigh 0.42g CsBr and 1.25g PbBr2 and dissolve them in 40mL dimethylformamide. After complete dissolution, filter to obtain the perovskite precursor solution. Take 10mL of the perovskite precursor solution in a 50mL small beaker and put it in a 106℃ preheated oven. After about 1h, crystals gradually precipitate. Take the precipitated crystals as seed crystals, add them to the beaker containing the new perovskite precursor solution, seal the beaker with tin foil, poke a small hole with a 5mL syringe, put it in a 70℃ preheated oven, and evacuate. After that, the oven temperature rises according to the set program. After four processes of constant temperature (60℃, 1h), rapid heating (60℃-80℃, 1h), slow heating (80℃-100℃, 30h) and constant temperature (100℃, 2h), the crystals can be taken out. The crystal was wiped dry with a dust-free cloth and rinsed with chlorobenzene. It was then placed in a vacuum oven and dried at room temperature for 1 hour and stored away from light to obtain a CsPbBr3 single crystal.

[0046] Step 2: Evaporating the first metal electrode on the upper and lower surfaces of the passivated perovskite single crystal

[0047] The CsPbBr3 single crystal was immersed in HBr solution for 2 hours, and the surface was cleaned with acetone after being taken out, and then a layer of Au metal electrode was evaporated on the surface.

[0048] Step 3: Prepare ring electrodes on the surface of the first metal electrode

[0049] The first metal electrode is cut by a laser of a certain power. The width and depth of the cut electrode should be appropriate to form a ring-shaped continuous electrode.

[0050] Example 2

[0051] Step 1: Prepare perovskite single crystal and passivate its surface

[0052] Preparation: Weigh 0.8g CH3NH3I and 2.5g PbI2 and dissolve them in 80mL dimethylformamide. After complete dissolution, filter to obtain the perovskite precursor solution. Take 20mL of the perovskite precursor solution in a 50mL small beaker and put it in a 110℃ preheated oven. After about 1h, crystals gradually precipitate. Take the precipitated crystals as seed crystals, add them to the beaker containing the new perovskite precursor solution, seal the beaker with tin foil, poke a small hole with a 5mL syringe, put it in a 70℃ preheated oven, and evacuate. After that, the oven temperature rises according to the set program. After four processes of constant temperature (60℃, 1h), rapid heating (60℃-80℃, 1h), slow heating (80℃-100℃, 30h) and constant temperature (100℃, 2h), the crystals can be taken out. The crystal was wiped dry with a dust-free cloth and rinsed with chlorobenzene. It was then placed in a vacuum oven and dried at room temperature for 1 hour and stored away from light to obtain a CH3NH3PbI3 single crystal.

[0053] Step 2: Evaporating the first metal electrode on the upper and lower surfaces of the passivated perovskite single crystal

[0054] Soak the CH3NH3PbI3 single crystal in HI solution for 2 hours, take it out and clean the surface with acetone, and then evaporate a layer of Ag metal electrode on the surface.

[0055] Step 3: Prepare ring electrodes on the surface of the first metal electrode

[0056] The first metal electrode is cut by a laser of a certain power. The width and depth of the cut electrode should be appropriate to form a ring-shaped continuous electrode.

[0057] Example 3

[0058] Step 1: Prepare perovskite single crystal and passivate its surface

[0059] Preparation Weigh 0.8g FABr and 2.5g PbBr2 and dissolve them in 80mL dimethylformamide. After complete dissolution, filter to obtain the perovskite precursor solution. Take 20mL of the perovskite precursor solution in a 50mL small beaker and put it in a 110℃ preheated oven. After about 1h, crystals gradually precipitate. Take the precipitated crystals as seed crystals, add them to the beaker containing the new perovskite precursor solution, seal the beaker with tin foil, poke a small hole with a 5mL syringe, put it in a 70℃ preheated oven, and evacuate. After that, the oven temperature rises according to the set program. After four processes of constant temperature (60℃, 1h), rapid heating (60℃-80℃, 1h), slow heating (80℃-100℃, 30h) and constant temperature (100℃, 2h), the crystals can be taken out. The crystal was wiped dry with a dust-free cloth and rinsed with chlorobenzene. It was then placed in a vacuum oven and dried at room temperature for 1 hour and stored away from light to obtain a FAPbBr3 single crystal.

[0060] Step 2: Evaporating the first metal electrode on the upper and lower surfaces of the passivated perovskite single crystal

[0061] The FAPbBr3 single crystal was immersed in HBr solution for 2 hours, and the surface was cleaned with acetone after being taken out, and then a layer of Ag metal electrode was evaporated on the surface.

[0062] Step 3: Prepare ring electrodes on the surface of the first metal electrode

[0063] The first metal electrode is cut by a laser of a certain power. The width and depth of the cut electrode should be appropriate to form a ring-shaped continuous electrode.

[0064] Comparative Example 1

[0065] Step 1: Prepare perovskite single crystal and passivate its surface

[0066] Preparation Weigh 0.42g CsBr and 1.25g PbBr2 and dissolve them in 40mL dimethylformamide. After complete dissolution, filter to obtain the perovskite precursor solution. Take 10mL of the perovskite precursor solution in a 50mL small beaker and put it in a 106℃ preheated oven. After about 1h, crystals gradually precipitate. Take the precipitated crystals as seed crystals, add them to the beaker containing the new perovskite precursor solution, seal the beaker with tin foil, poke a small hole with a 5mL syringe, put it in a 70℃ preheated oven, and evacuate. After that, the oven temperature rises according to the set program. After four processes of constant temperature (60℃, 1h), rapid heating (60℃-80℃, 1h), slow heating (80℃-100℃, 30h) and constant temperature (100℃, 2h), the crystals can be taken out. The crystal was wiped dry with a dust-free cloth and rinsed with chlorobenzene. It was then placed in a vacuum oven and dried at room temperature for 1 hour and stored away from light to obtain a CsPbBr3 single crystal.

[0067] Step 2: Evaporate Au metal electrodes on the upper and lower surfaces of the perovskite single crystal

[0068] Step 3: Use a laser of a certain power to cut the Au metal electrode. The width and depth of the cut electrode should be appropriate to form a ring-shaped continuous electrode.

[0069] Comparative Example 2

[0070] Step 1: Prepare perovskite single crystal and passivate its surface

[0071] Preparation Weigh 0.42g CsBr and 1.25g PbBr2 and dissolve them in 40mL dimethylformamide. After complete dissolution, filter to obtain the perovskite precursor solution. Take 10mL of the perovskite precursor solution in a 50mL small beaker and put it in a 106℃ preheated oven. After about 1h, crystals gradually precipitate. Take the precipitated crystals as seed crystals, add them to the beaker containing the new perovskite precursor solution, seal the beaker with tin foil, poke a small hole with a 5mL syringe, put it in a 70℃ preheated oven, and evacuate. After that, the oven temperature rises according to the set program. After four processes of constant temperature (60℃, 1h), rapid heating (60℃-80℃, 1h), slow heating (80℃-100℃, 30h) and constant temperature (100℃, 2h), the crystals can be taken out. The crystal was wiped dry with a dust-free cloth and rinsed with chlorobenzene. It was then placed in a vacuum oven and dried at room temperature for 1 hour and stored away from light to obtain a CsPbBr3 single crystal.

[0072] Step 2: Evaporating the first metal electrode on the upper and lower surfaces of the passivated perovskite single crystal

[0073] The CsPbBr3 single crystal was immersed in HBr solution for 2 hours, and the surface was cleaned with acetone after being taken out, and then a layer of Au metal electrode was evaporated on the surface.

[0074] The noise power spectra of the perovskite single crystal detectors obtained in Examples 1 to 3 and Comparative Examples 1 to 2 were tested by an electrometer, and the test results are shown in the following table.

[0075] Example <![CDATA[Noise (A.U 2 . / Hz)]]> Example 1 5 Example 2 8 Example 3 3 Comparative Example 1 60 Comparative Example 2 80

[0076] It can be seen from the data in the table that, compared with comparative examples 1 to 2, the noise of the perovskite optoelectronic devices of embodiments 1 to 3 is significantly reduced.

[0077] Figure 4 The figure is a comparison of the current performance test of the CsPbBr3 perovskite optoelectronic device passivated with the passivating agent (F and 5F) prepared in Example 1 and the CsPbBr3 perovskite optoelectronic device not passivated prepared in Comparative Example 1, wherein the lower the dark current, the better the performance of the perovskite optoelectronic device. Figure 4 It can be seen that the dark current of the CsPbBr3 perovskite optoelectronic device after passivation with 5F passivator is significantly lower than that of the CsPbBr3 perovskite optoelectronic device without passivation treatment.

[0078] Figure 5 The noise test results of the power spectrum density of the CsPbBr3 perovskite optoelectronic device with a ring-shaped metal electrode prepared in Example 1 and the CsPbBr3 perovskite optoelectronic device without a ring-shaped metal electrode in Comparative Example 2 are shown in FIG. Figure 5 It can be seen that from the frequency range 10 -3 Hz to 10 -1 Hz, the noise data measured in Example 1 are much lower than the noise data in Comparative Example 2, indicating that the low-noise perovskite optoelectronic device prepared by the present invention has the effect of significantly reducing the noise of the perovskite optoelectronic device.

[0079] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-noise perovskite optoelectronic device, characterized in that: The perovskite optoelectronic device comprises a first metal electrode, a perovskite layer, and a second metal electrode; The first metal electrodes are respectively deposited on the upper and lower surfaces of the perovskite layer; The second metal electrode is a ring-shaped electrode prepared on the surface of the first metal electrode. The second metal electrode is surrounded by the first metal electrode to prevent the lateral diffusion of the charge of the first metal electrode.

2. A low-noise perovskite optoelectronic device as claimed in claim 1, characterized in that: The perovskite layer is an organic-inorganic composite perovskite single crystal with an ABX3 molecular structure.

3. A low-noise perovskite optoelectronic device as claimed in claim 2, characterized in that: The perovskite layer is CsPbBrI3, CH3NH3PbI3, CH3NH3PbBr3, FAPbBr3, PEABr and FA 1-x Cs x Any one of PbBr3(x=0.05,0.1).

4. A low-noise perovskite optoelectronic device as claimed in claim 1, characterized in that: The perovskite layer is passivated by a strong acid solution.

5. A low-noise perovskite optoelectronic device as claimed in claim 1, characterized in that: The second metal electrode is any one of Au, Ag, Al, Bi, C, Pb, and ITO.

6. A method for preparing a low-noise perovskite optoelectronic device, characterized in that: The steps include: S1: Preparation of perovskite single crystals and passivation of their surfaces; S2: evaporating a first metal electrode on the upper and lower surfaces of the passivated perovskite single crystal; S3: preparing ring-shaped electrodes on the surface of the first metal electrode respectively, so that the ring-shaped electrodes are surrounded by the inside of the first metal electrode.

7. The method for preparing a low-noise perovskite optoelectronic device according to claim 6, characterized in that: The passivation treatment comprises: A strong acid solvent is used to passivate the surface of the perovskite single crystal. The strong acid solvent is an acid containing a halogen element, and the halogen element is the same as the halogen element of the perovskite single crystal.

8. The method for preparing a low-noise perovskite optoelectronic device according to claim 6, characterized in that: The method of preparing the ring-shaped electrode includes cutting the first metal electrode by laser to form a continuous electrode in the shape of a circular ring.

9. Use of the method according to any one of claims 6 to 8 in preparing a low-noise perovskite optoelectronic device.

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