Photoelectric device based on enhanced photoelectric recycling effect, preparation method and application

Abstract

The present disclosure provides a photoelectric device based on enhanced photoelectric recycling effect, comprising: a substrate; a P-type electrode layer, which is located at one end of the substrate surface; a bottom battery layer, which is located at the other end of the substrate surface to be connected to the P-type electrode layer, and the bottom battery layer is used to absorb excitation light photons and convert them into electrons to achieve photoelectric-electro-optical conversion; a highly doped tunnel junction layer, which is located on the bottom battery and is used to provide a low-resistance and optically low-loss connection; a top battery layer, which is located on the highly doped tunnel junction layer and is used to absorb excitation light photons and convert them into electrons to achieve photoelectric conversion; wherein the energy band width of the top battery layer is greater than or equal to the energy band width of the bottom battery layer; an N-type electrode layer, which is located at one end of the surface of the top battery layer. The present disclosure also provides a method for preparing a photoelectric device based on enhanced photoelectric recycling effect and its application.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor optoelectronic devices, and in particular to optoelectronic devices based on enhanced photoelectric recycling effect, preparation methods and applications. Background Art

[0002] Understanding and engineering optical processes in semiconductor materials are crucial for realizing high-performance optoelectronic devices such as photovoltaic (PV) cells, photodetectors, light-emitting diodes (LEDs), and lasers. In light-emitting semiconductors, photon absorption, re-emission, and self-absorption processes, also known as the photon recycling effect, are of great interest in the study of photon receivers. In particular, remarkable results have recently been shown on III-V and halide perovskite-based semiconductors, where the improved photon recycling effect leads to single-junction or multi-junction PV cells with ultra-high power conversion efficiency. In these PV cells, the enhanced photon recycling effect increases the open-circuit voltage (Voc) and photogenerated current, resulting in more efficient conversion outputs for optoelectronic devices.

[0003] Typically, the photon recycling effect is mainly carried out under standard single-day illumination of PV cells, where various strategies, such as reflector optimization and light capture design, have been adopted to manipulate the internally radiated photons. At the same time, the optoelectronic properties of semiconductor materials and devices (quantum efficiency, carrier lifetime, etc.) depend on the wavelength and power of the incident light, but the impact of photon recycling has been less studied. Especially in multi-junction devices, the photon recycling process will affect and change the current matching conditions of multi-junction cells.

[0004] The present invention discloses the photon recycling process in an optoelectronic device enhanced by the photoelectric recycling effect, and experimentally and analytically studies the photon and carrier transport behaviors at various wavelengths and intensities. In the optoelectronic device, it is found that the incident wavelength of the excitation light affects the current matching conditions, resulting in a varying photon recycling effect. Under violet-blue (400-480nm) and near-infrared (~800nm) illumination, the dependence of the output current of the optoelectronic device on the incident power is significantly different. These results show that the photon recycling effect plays a vital role in the design of optoelectronic devices. Summary of the invention

[0005] In order to solve the above problems in the prior art, the present disclosure provides a photoelectric device, a preparation method and an application based on enhanced photoelectric recovery effect, which achieves higher internal quantum efficiency and higher device output voltage of the photoelectric device by rationally designing the structure, preparation materials and thin film thickness of the photoelectric device.

[0006] The first aspect of the present disclosure provides a photoelectric device based on enhanced photoelectric recovery effect, comprising: a substrate; a P-type electrode layer, which is located at one end of the substrate surface; a bottom battery layer, which is located at the other end of the substrate surface to be connected to the P-type electrode layer, and the bottom battery layer is used to absorb excitation light photons and convert them into electrons to achieve photoelectric-electro-optical conversion; a highly doped tunnel junction layer, which is located on the bottom battery and is used to provide a low-resistance and optically low-loss connection; a top battery layer, which is located on the highly doped tunnel junction layer and is used to absorb excitation light photons and convert them into electrons to achieve photoelectric conversion; wherein the energy band width of the top battery layer is greater than or equal to the energy band width of the bottom battery layer; and an N-type electrode layer, which is located at one end of the surface of the top battery layer.

[0007] Furthermore, the internal quantum efficiency η of the optoelectronic device is int The following relations are satisfied:

[0008]

[0009] Where R is a function related to excess carrier density, and B is 1.5×10 -10 s -1 cm 3 constant, h0 is the hole density of the photoelectric device in the thermal equilibrium state, Δh is the excess hole density of the photoelectric device, q0 is the electron density of the photoelectric device in the thermal equilibrium state, Δq is the excess electron density of the photoelectric device, and n i is the density of intrinsic carriers.

[0010] Furthermore, a DC bias is applied between the P-type electrode layer and the N-type electrode layer, and the current I in the photoelectric device and its internal quantum efficiency η int The following relations are satisfied:

[0011]

[0012] Among them, I ex is the current of the photon flux of the incident excitation light.

[0013] Further, the layer thickness of the top cell layer is smaller than the layer thickness of the bottom cell layer.

[0014] Furthermore, the bottom battery layer is a GaAs battery layer or an InGaAs battery layer or an InP battery layer.

[0015] Furthermore, the top battery layer is a GaP battery layer, a GaN battery layer, or a GaAs battery layer.

[0016] Furthermore, the N-type electrode layer is formed by sequentially stacking Ge, Ni and Au metals.

[0017] Furthermore, the P-type electrode layer is formed by sequentially stacking Cr and Au metals.

[0018] The second aspect of the present disclosure provides a method for preparing a photovoltaic device based on an enhanced photoelectric recovery effect, comprising: S1, sequentially growing a bottom battery layer, a highly doped tunnel junction layer and a top battery layer on a substrate; S2, forming a P-type electrode layer on one side of the substrate using evaporated metal; S3, forming an N-type electrode layer on one side of the top battery layer using evaporated metal.

[0019] A third aspect of the present disclosure provides an application of an optoelectronic device based on an enhanced photoelectric recycling effect in a high-performance optoelectronic device.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The optimized optoelectronic device provided by the present disclosure can achieve the best photoelectric recovery effect response at around 800nm, such as a highly efficient near-infrared photodetector.

[0022] (2) The optoelectronic device based on GaAs material provided in the present disclosure is more suitable for realizing the photon recovery process than InGaP, and has a higher internal quantum efficiency.

[0023] (3) Compared with devices with thicker material layers, the serially connected ultra-thin GaAs junctions provided by the present disclosure have higher carrier collection efficiency and can achieve high output voltage.

[0024] (4) The optoelectronic device provided by the present disclosure is a double-junction device with high current mismatch, which clearly shows a strong photon recovery efficiency related to the excitation light input power.

[0025] (5) The bottom cell layer can be made of low bandgap absorber materials such as InGaAs or InP. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] For a more complete understanding of the present disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1A A perspective view schematically shows a photoelectric device based on enhanced photoelectric recycling effect according to an embodiment of the present disclosure;

[0028] Figure 1B A schematic diagram showing the effect of a photoelectric device based on enhanced photoelectric recycling effect on glass by a transfer printing method according to an embodiment of the present disclosure is shown;

[0029] Figure 1C A schematic diagram showing a comparison of external quantum efficiency spectra of a top cell and a bottom cell at different input excitation light wavelengths according to an embodiment of the present disclosure;

[0030] Figure 1DA schematic diagram showing a comparison of external quantum efficiency spectra under 850nm and 470nm saturated bias excitation light according to an embodiment of the present disclosure;

[0031] Figure 2A and Figure 2B Schematically showing the optical contrast diagram inside the optoelectronic device under the irradiation of incident excitation light of 475nm and 810nm according to the embodiment of the present disclosure;

[0032] Figure 2C A comparison diagram of photon distribution effects of the optoelectronic device with different layer thicknesses according to an embodiment of the present disclosure is schematically shown;

[0033] Figure 2D A schematic diagram showing a comparison of internal quantum efficiencies of a bottom battery at different bias voltages according to an embodiment of the present disclosure;

[0034] Figure 3A and 3B A schematic diagram showing a PL attenuation comparison diagram of incident excitation light at different optical power densities at 800nm ​​and 410nm according to an embodiment of the present disclosure;

[0035] Figure 3C A comparison diagram of the PL decay lifetime τ and the photon flux of the incident excitation light at 800nm ​​and 410nm according to an embodiment of the present disclosure is schematically shown;

[0036] Figure 3D The internal quantum efficiency η of the incident excitation light at 800 nm and 410 nm according to the embodiment of the present disclosure is schematically shown. int Comparison chart;

[0037] Figure 4A and 4B A schematic diagram showing a comparison of current-voltage characteristics of incident excitation light at different optical power densities of 800nm ​​and 410nm according to an embodiment of the present disclosure;

[0038] Figure 4C A schematic diagram showing the relationship between the current and the excitation power of the incident excitation light at 800nm ​​and 475nm according to an embodiment of the present disclosure;

[0039] Figure 4D Schematically shows different internal quantum efficiencies η of the optoelectronic device of the embodiment of the present disclosure int Comparison of external quantum efficiency spectra under ;

[0040] Figure 5A The schematic diagram schematically shows the response of the GaAs / InGaAs battery layer to different wavelengths according to another embodiment of the present disclosure;

[0041] Figure 5BSchematically showing the conversion response of a GaAs / InGaAs optoelectronic device to different wavelengths under different photon recycling effect enhancements according to another embodiment of the present disclosure;

[0042] Fig. 6A The schematic diagram schematically shows the response of the GaAs / InP battery layer to different wavelengths according to another embodiment of the present disclosure;

[0043] Figure 6B A schematic diagram showing the conversion response of a GaAs / InGaAs optoelectronic device to different wavelengths under different photon recycling effect enhancements according to another embodiment of the present disclosure is shown;

[0044] Figure 7 The flowchart of preparing a photoelectric device based on enhanced photoelectric recycling effect according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0045] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0046] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be intermediate elements. Moreover, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element through a third element.

[0047] As shown in FIG1 , the optoelectronic device based on the enhanced photoelectric recycling effect according to the embodiment of the present disclosure includes:

[0048] Substrate 1, which is a GaAs substrate.

[0049] The P-type electrode layer 2 is located at one end of the surface of the substrate 1. The P-type electrode layer 2 is formed by sequentially stacking Cr and Au metals, and has a layer thickness of 200 nm.

[0050] The bottom battery layer 3 is located at the other end of the surface of the substrate 1 to be connected to or arranged opposite to the P-type electrode layer 2. The bottom battery layer 3 is used to absorb excitation light photons and convert them into electrons to achieve photoelectric-electro-optical conversion.

[0051] In the embodiment of the present disclosure, the bottom battery layer 3 adopts a photovoltaic structure for long wavelength absorption conversion or a photovoltaic material with the same upper and lower layers of greater thickness, such as a silicon battery or a GaAs battery layer or an InP battery layer. The present disclosure embodiment takes a GaAs structure battery layer with a greater thickness as an example as the bottom battery layer 3, which includes a p-type InGaP-BSF layer, a p-type GaAs substrate, an n-type GaAs emitter and an n-type Al2O3 layer grown on the surface of the substrate in sequence. 0.3 Ga 0.7 As window, in which the p-type InGaP-BSF layer is doped with a concentration of 1×10 18 cm -3 The p-type GaAs substrate is formed by Mg doping with a layer thickness of 500nm and a doping concentration of 1×10 17 cm -3 The Zn doping is formed with a layer thickness of 450nm, and the n-type GaAs emitter is formed with a doping concentration of 2×10 18 cm -3 Si doping is formed, the layer thickness is 100nm, n-type Al 0.3 Ga 0.7 The As window is doped with a concentration of 2×10 18 cm -3 The Si doping is formed, and the layer thickness is 30nm.

[0052] The highly doped tunnel junction layer 4 is located on the bottom battery layer 3. The highly doped tunnel junction layer 4 is located between the bottom battery layer 3 and the top battery layer 5 to provide a low resistance and optical low loss connection. The highly doped tunnel junction layer 4 includes an N-type GaAs layer and a P-type GaAs layer located on the surface of the bottom battery layer 3 in sequence. The N-type GaAs layer is doped with Se at a concentration of 9×10 19 cm -3 The N-type GaAs layer has a thickness of 11 nm and the P-type GaAs layer has a C doping concentration of 8×10 19 cm -3 The P-type GaAs layer has a thickness of 11 nm.

[0053] The top battery layer 5 is located on the highly doped tunnel junction layer 4, wherein the energy band width of the top battery layer 5 is greater than or equal to the energy band width of the bottom battery layer 3, and is used to absorb excitation light photons and convert them into electrons to achieve photoelectric conversion. In the embodiment of the present disclosure, the top battery layer 5 adopts a photoelectric structure for short wavelengths that can achieve "photoelectric / electro-optical" or a photoelectric material with a smaller thickness and the same upper and lower layers, such as a GaP battery layer or a GaN battery layer or a GaAs battery layer. The embodiment of the present disclosure takes a thinner GaAs structure battery layer as an example as the top battery layer 5, which includes a P-type Al2O3 layer sequentially grown on the surface of the highly doped tunnel junction layer 4. 0.3 Ga 0.7As-BSF layer, P-type GaAs base, N-type GaAs emitter and n-type InGaP window, the P-type Al 0.3 Ga 0.7 The As-BSF layer is doped with a concentration of 5×10 18 cm -3 The P-type GaAs base is formed by Mg doping with a layer thickness of 100nm. 17 cm -3 The N-type GaAs emitter is formed by Zn doping with a layer thickness of 1500nm. 18 cm -3 The N-type InGaP window is formed by Si doping with a layer thickness of 100nm. 18 cm -3 The Si doping is formed, and the layer thickness is 30nm.

[0054] The N-type electrode layer 6 is located at one end of the surface of the top battery layer 5. The N-type electrode layer 6 is formed by sequentially stacking Ge, Ni and Au metals, and has a layer thickness of 200 nm.

[0055] The P-type electrode layer 2 and the N-type electrode layer 6 are used to form a good ohmic contact with an external circuit.

[0056] Figure 1B The schematic diagram shows the effect of a photoelectric device based on enhanced photoelectric recycling effect on glass by a transfer printing method according to an embodiment of the present disclosure. The size of the photoelectric device is 700 μm×700 μm, and the total layer thickness is 3.8 μm.

[0057] According to an embodiment of the present disclosure, the external quantum efficiency (EQE) spectra of the top battery layer 5 and the bottom battery layer 3 at different input excitation light wavelengths are calculated using the finite element method, such as Figure 1C As shown, according to the design of the size, material and thickness of each layer of the optoelectronic device, the optoelectronic device achieves the maximum EQE at about 800nm, wherein the top battery layer 5 and the bottom battery layer 3 absorb an equivalent amount of photons, and current matching is achieved between the two battery layers. At other wavelengths of incident excitation light, due to its deviation from the current matching condition, the total current of the optoelectronic device is determined by the sub-battery with smaller current output. Therefore, the total EQE of the optoelectronic device is lower than the EQE of the top battery layer 5 and the bottom battery layer 3.

[0058] According to the embodiment of the present disclosure, during the experiment, 850nm and 470nm saturated bias light were input to the optoelectronic device respectively, and the EQE of the top battery layer 5, the bottom battery layer 3 and the optoelectronic device under the saturated bias light were measured respectively, and the irradiation intensity of the monochromatic light was 1-3mW / cm 2 ,like Figure 1D As shown, it can be seen that the experimental results are consistent with Figure 1C The calculated results are moderately good, with some discrepancies caused by thickness variations during epitaxial layer deposition and unwanted carrier losses on the surface of the optoelectronic device.

[0059] According to the embodiments of the present disclosure, during the experiment, the optoelectronic device was illuminated with monochromatic light of 475 nm and 810 nm, and the EQE under the illumination of different light sources was measured, such as Figure 2A As shown in FIG. 1 , at 475 nm, more than 99% of the photons are captured and absorbed by the top cell layer 5, which generates much more free carriers than the bottom cell. When the top cell layer 5 is connected in series with the bottom cell layer 3 and measured under short-circuit conditions, i.e., V=0, the total photocurrent generated is negligible, so that the EQE is close to zero. Figure 2B As shown, compared with 475nm irradiation light, 810nm infrared light can penetrate deeper into the cell layer, resulting in a more uniform photon distribution, so it can achieve current matching and thus achieve maximum EQE.

[0060] Those skilled in the art will know that in highly luminescent materials such as GaAs, if they cannot be collected by external circuits due to current mismatch, photons and carriers can be "recycled" through re-emission and re-absorption, and this photon recycling effect may in turn change the photon distribution inside the device. Figure 2A As shown, the photogenerated electrons and holes in the top cell layer 5 are captured and recombine through radiation and non-radiation processes. The radiation meets the creation of re-emitted photons at the edge of the semiconductor. The photons are redistributed throughout the device, generating photocarriers in the top cell layer 5, that is, the bottom cell layer 3, and resulting in a non-zero photocurrent. The changing photons depend on the radiation efficiency of the semiconductor material, that is, the internal quantum efficiency η int .

[0061] According to the embodiments of the present disclosure, Figure 2C As shown, according to the Beer-Lambert law, the corresponding relationship between the photon distribution at different incident excitation light 475nm and 870nm and the different layer thickness of the optoelectronic device is plotted and calculated. int = 0, irradiate 475nm blue light, and strictly follow the Beer-Lambert law. int The increase in the wavelength of the photon needs to take into account the photons re-emitted at 870 nm, which will penetrate deeper into the optoelectronic device due to the reduced absorption coefficient of GaAs. It can be seen that this photon recycling process may seriously affect the performance of the bottom cell. In the embodiment of the present disclosure, it is assumed that the incident power of the 475 nm blue light illumination is 400 W / m 2 , and calculate different η intThe current-voltage characteristics of the top battery layer 5 and the bottom battery layer 3 in the photovoltaic device are shown below. When the photovoltaic device is operated under short-circuit conditions, its total current I and total voltage V satisfy the following relationship with the top battery layer 5 (I1, V1) and the bottom battery layer 3 (I2, V2):

[0062] I=I1=I2,V1+V2=0

[0063] According to the embodiments of the present disclosure, Figure 2D As shown, the intersection point in the figure represents the working conditions of the top cell layer 5 and the bottom cell layer 3 of the optoelectronic device at 475nm. The top cell layer 5 is set to forward bias and emit IR photons, and the bottom cell layer 3 receives the recycled IR photons and works at reverse bias. Compared with the incident light of 475nm, this photon recycling effect is negligible at the incident light of 810nm, as shown in FIG. Figure 2B As shown, because under the current matching conditions, the photogenerated carriers will be immediately collected by the external circuit. In the embodiment of the present disclosure, in order to experimentally verify the photocarrier dynamics characteristics of the optoelectronic device, time-resolved photoluminescence (TRPL) measurements were performed using a femtosecond laser at different excitation wavelengths, as shown in FIG. Figure 3A and Figure 3B As shown in the figure, the PL attenuation of incident excitation light at different power densities of 800nm ​​and 410nm was tested respectively. When the incident excitation light was at 800nm, the power density range was 1.4×10 4 W / m 2 ~1.4×10 7 W / m 2 ( Figure 3A The power density corresponding to the curve from bottom to top increases); when the incident excitation light is 410nm, the power density selection range is 1×10 5 W / m 2 ~1.4×10 7 W / m 2 ( Figure 3B The power density corresponding to the curve from bottom to top increases), such as Figure 3C As shown, the PL decay lifetime τ as a function of photon flux at two wavelengths is derived compared with the fitting curve based on the standard ABC model:

[0064]

[0065] Here, R represents non-radiative recombination and is a function of excess carrier density, and B represents radiative recombination, assuming B is 1.5×10 -10 s -1 cm 3The constant Z is related to Auger recombination, which can be ignored at relatively low carrier density; q0 is the electron density of the photoelectric device in thermal equilibrium, and Δq is the excess electron density of the photoelectric device. The difference between the analysis and fitting curve and the measured data is as follows Figure 3C As shown in the figure, the corresponding quantum efficiency is obtained based on the relationship between lifetime and carrier concentration. Due to the complex non-radiative recombination mechanism, such as surface defects, deep energy level traps, etc., it is difficult to model with the above formula. And the internal quantum efficiency η int It can be expressed as the radiative recombination rate C rad and the non-radiative recombination rate C non-rad Ratio:

[0066]

[0067] Where p0 is the excess hole density of the optoelectronic device, Δp is the excess hole density of the optoelectronic device, and n i is the density of intrinsic carriers. According to the embodiment of the present disclosure, based on the experimental results of τ, η can be calculated int As a function of photon flux, Figure 3D As shown, η int It increases monotonically with the absorbed photon flux, which is attributed to the gradual saturation effect of non-radiative recombination centers.

[0068] According to the embodiment of the present disclosure, the current-voltage characteristics of the incident excitation light at different optical power densities of 810nm and 475nm were tested. When the incident excitation light was 810nm, the power density range was 0.02W / m 2 ~2.2×10 6 W / m 2 ; When the incident excitation light is at 475nm, the power density is selected in the range of 70W / m 2 ~10 6 W / m 2 .like Figure 4A and 4B As shown, the open circuit voltage of the photoelectric device is about 2V, and its optical circuit increases with the increase of irradiation power. Under the irradiation of 810nm and 475nm light sources, the relationship between the measured current density and the excitation power is as follows: Figure 4C As shown, at 810 nm, the photons absorbed by the optoelectronic device are almost evenly distributed in each material layer of the optoelectronic device, as shown in FIG. Figure 1C As shown, the photon absorption rate in the top battery layer 5 and the bottom battery layer 3 is about 40%. Therefore, when the optoelectronic device reaches the current matching condition, the output current is linearly proportional to the excitation power:

[0069] I=I ex ×EQE

[0070] Among them, Iex On the contrary, under 475nm light irradiation, most of the photons are absorbed by the top cell layer 5, and only a small part of the photogenerated carriers produce re-emitted photons, which are absorbed by the bottom cell, such as Figure 2A As shown. Therefore, the total current is determined by the battery cell with the smaller current output. Therefore, the output current depends on the photon recovery efficiency:

[0071]

[0072] Among them, η LC is the light coupling efficiency, which is mainly related to η int It is related to the collective shape of the optoelectronic device, namely:

[0073]

[0074] in, and is the probability that the internal photon is reabsorbed inside the top cell layer 5 and coupled to the bottom cell in the photovoltaic device, which is determined by the structure of the top cell layer 5 and the bottom cell layer 3. Further, it can be obtained:

[0075]

[0076] In the disclosed embodiment, η obtained by experiment int The value is applied to the above formula to calculate the output current I of the photoelectric device and obtain Figure 4C The calculated results are in good agreement with the experimental results and are superlinear with the excitation light power density. The difference between the experimental results and the calculated results indicates that there are other non-radiative recombination mechanisms in the optoelectronic device in the actual process. Figure 1D The measured EQE results are consistent, with the photoresponse at 475nm being several orders of magnitude lower than that at 810nm. When the illumination power increases, the photocurrent at 475nm grows faster than that at 810nm due to the enhanced photon recycling effect. Although two monochromatic light sources were used to study the operation of this optoelectronic device, the photon and carrier processes at other wavelengths can be analyzed based on similar principles, depending on the current matching / mismatching status. For this optoelectronic device, its EQE spectrum changes with the illumination intensity of different wavelengths, Figure 4D This effect is conceptually predicted based on the assumption that, ideally, when η intNear 100%, the EQE spectrum may plateau over a wide range, behaving similarly to a single-junction GaAs photodiode, but with double the output voltage. In this case, most free carriers can radiatively recombine and form infrared photons that can be recovered by the bottom cell. Therefore, current matching can be achieved between subcells at most wavelengths. It should be noted that the photon recovery efficiency decreases at ultra-high illumination power densities, as the Auger process starts to dominate the non-radiative recombination.

[0077] In another embodiment of the present disclosure, the top battery layer 5 is a GaAs battery layer, and the bottom battery layer 3 is an InGaAs battery layer. Figure 5A The schematic diagram of the response of GaAs / InGaAs battery layer to different wavelengths is shown in Figure 2. Figure 5A As shown, the absorption efficiency of the double-layer structure GaAs / InGaAs with a top GaAs cell and a bottom InGaAs cell at different wavelengths is demonstrated.

[0078] like Figure 5B The figure shows the conversion response of GaAs / InGaAs optoelectronic devices to different wavelengths under different photon recycling effect enhancements. Figure 5B As shown, under the action of the photon recycling effect, the spectral response efficiency of the double-layer GaAs / InGaAs structure is significantly enhanced.

[0079] In another embodiment of the present disclosure, the top battery layer 5 is a GaAs battery layer, and the bottom battery layer 3 is an InP battery layer. Fig. 6A The schematic diagram of the response of GaAs / InP battery layer to different wavelengths is shown in Figure 2. Fig. 6A As shown, the absorption efficiency of the double-layer structure GaAs / InP with a top GaAs cell layer and a bottom InP cell layer at different wavelengths is demonstrated.

[0080] like Figure 6B The figure shows the conversion response of GaAs / InP optoelectronic devices to different wavelengths under different photon recycling effect enhancements. Figure 6B As shown, under the action of the photon recycling effect, the spectral response efficiency of the double-layer GaAs / InP structure is significantly enhanced.

[0081] According to the embodiments of the present disclosure, based on the optoelectronic performance of the optoelectronic device, the intensity illumination and wavelength dependence of the corresponding photon recycling effect under different device layer thicknesses and materials are studied. In addition, the study also proves that the photon recycling effect also significantly affects the photocurrent in the multi-junction device by changing the photon coupling between the sub-cells.

[0082] Figure 7 The flowchart of preparing a photoelectric device based on enhanced photoelectric recycling effect according to an embodiment of the present disclosure is schematically shown.

[0083] like Figure 7 As shown, an embodiment of the present disclosure provides a method for preparing a photoelectric device based on an enhanced photoelectric recovery effect, comprising: S1, sequentially growing a bottom battery layer, a highly doped tunnel junction layer and a top battery layer on a substrate; S2, forming a P-type electrode layer on one side of the substrate using evaporated metal; S3, forming an N-type electrode layer on one side of the top battery layer using evaporated metal.

[0084] The optoelectronic device is produced by using a metal organic chemical vapor deposition (MOCVD) method. The substrate is a GaAs substrate. The P-type electrode layer is composed of Cr and Au metals grown in layers in sequence, with a layer thickness of 200nm. The bottom battery layer includes a p-type InGaP-BSF layer, a p-type GaAs substrate, an n-type GaAs emitter, and an n-type Al2O3 layer grown in sequence on the surface of the substrate. 0.3 Ga 0.7 As window, in which the p-type InGaP-BSF layer is doped with a concentration of 1×10 18 cm -3 The p-type GaAs substrate is formed by Mg doping with a layer thickness of 500nm and a doping concentration of 1×10 17 cm -3 The Zn doping is formed with a layer thickness of 450nm, and the n-type GaAs emitter is formed with a doping concentration of 2×10 18 cm -3 Si doping is formed, the layer thickness is 100nm, n-type Al 0.3 Ga 0.7 The As window is doped with a concentration of 2×10 18 cm -3 The highly doped tunnel junction layer is located between the bottom battery layer and the top battery layer to provide a low resistance and optical low loss connection, and includes an N-type GaAs layer and a P-type GaAs layer located on the surface of the bottom battery in sequence. The n-type GaAs layer is doped with Se at a concentration of 9×10 19 cm -3 The N-type GaAs layer has a thickness of 11 nm and the p-type GaAs layer has a C doping concentration of 8×10 19 cm -3 A p-type GaAs layer having a thickness of 11 nm; a top battery layer located on the highly doped tunnel junction layer, wherein the energy band width of the top battery layer is greater than or equal to the energy band width of the bottom battery layer, and the top battery layer includes p-type Al sequentially grown on the surface of the highly doped tunnel junction layer. 0.3 Ga 0.7 As-BSF layer, p-type GaAs base, n-type GaAs emitter and n-type InGaP window, the p-type Al 0.3 Ga 0.7The As-BSF layer is doped with a concentration of 5×10 18 cm -3 The p-type GaAs base is formed by Mg doping with a layer thickness of 100 nm. 17 cm -3 The n-type GaAs emitter is formed by Zn doping with a layer thickness of 1500nm. 18 cm -3 The n-type InGaP window is formed by Si doping with a layer thickness of 100nm. 18 cm -3 The Si doping is formed with a layer thickness of 30nm; the N-type electrode layer is located at one end of the surface of the top battery layer, and the N-type electrode layer is composed of Ge, Ni and Au metals grown in sequence, with a layer thickness of 200nm; wherein, the bottom battery layer and the top battery layer are used to absorb the excitation light photons and convert them into electrons, and the P-type electrode layer and the N-type electrode layer are used to form a good ohmic contact with the external circuit.

[0085] According to the embodiment of the present disclosure, a sacrificial layer is grown between the substrate and the bottom battery layer, and the sacrificial layer is Al 0.95 Ga 0.05 As, the layer thickness is 500nm, which is removed by dilute hydrofluoric acid HF solution Al0.95Ga0.05As sacrificial layer to form an independent thin film optoelectronic device, wherein the volume ratio of the HF solution is HF: water = 1: 10, containing a small amount of ethanol. Finally, a patterned polydimethylsiloxane (PDMS) stamp is used to pick up the released optoelectronic device and then transfer it to various carrier substrates with a spin-coated adhesive layer, such as glass, polyimide film and silicon.

[0086] The present disclosure also discloses the application of the above-mentioned optoelectronic device based on the enhanced photoelectric recycling effect in high-performance optoelectronic devices.

[0087] Specifically, the optoelectronic devices based on the enhanced photoelectric recycling effect provided by the present disclosure can realize high-performance photon recycling effects such as solar cells, photodetectors, light-emitting diodes (LEDs) and lasers, so that each optoelectronic device has ultra-high power conversion efficiency based on the improved photon recycling effect.

[0088] In the embodiments of the present disclosure, according to actual application requirements, the material and thickness of each material layer are not limited to those shown above, and can be adjusted accordingly according to actual requirements.

[0089] While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive.

[0090] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of scopes, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of scopes without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0091] Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, it should be understood by those skilled in the art that various changes in form and details may be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-mentioned embodiments, but should be determined not only by the appended claims, but also by the equivalents of the appended claims.

Claims

1. A photoelectric device based on enhanced photoelectric recycling effect, characterized in that: include: substrate; A P-type electrode layer, which is located at one end of the substrate surface; A bottom battery layer, which is located at the other end of the substrate surface to be connected to the P-type electrode layer, and is used to absorb excitation light photons and convert them into electrons to achieve photoelectric-electro-optical conversion; A highly doped tunnel junction layer, located on the bottom cell, for providing a low resistance and optically low loss connection; A top battery layer, which is located on the highly doped tunnel junction layer and is used to absorb excitation light photons and convert them into electrons to achieve photoelectric conversion; wherein the energy band width of the top battery layer is greater than or equal to the energy band width of the bottom battery layer; An N-type electrode layer, which is located at one end of the surface of the top battery layer; Wherein, the bottom battery layer is an InGaAs battery layer or an InP battery layer; The top cell layer is a GaAs cell layer.

2. The photoelectric device based on enhanced photoelectric recycling effect according to claim 1, characterized in that: The internal quantum efficiency of the optoelectronic device The following relations are satisfied: Where R is a function related to excess carrier density, and B is 1.5×10 -10 s -1 cm 3 The constant, is the hole density of the optoelectronic device in thermal equilibrium, is the excess hole density of the optoelectronic device, is the electron density of the photoelectric device in thermal equilibrium, is the excess electron density of the optoelectronic device, is the density of intrinsic carriers.

3. The photoelectric device based on enhanced photoelectric recycling effect according to claim 1, characterized in that: A DC bias is applied between the P-type electrode layer and the N-type electrode layer, and the current I in the photoelectric device and its internal quantum efficiency The following relations are satisfied: in, is the current of the photon flux of the incident excitation light.

4. The photoelectric device based on enhanced photoelectric recycling effect according to claim 1, characterized in that: The layer thickness of the top cell layer is smaller than the layer thickness of the bottom cell layer.

5. The photoelectric device based on enhanced photoelectric recycling effect according to claim 1, characterized in that: The N-type electrode layer is formed by sequentially stacking Ge, Ni and Au metals.

6. The photoelectric device based on enhanced photoelectric recycling effect according to claim 1, characterized in that: The P-type electrode layer is formed by sequentially stacking Cr and Au metals.

7. A method for preparing a photoelectric device based on enhanced photoelectric recycling effect applied to a photoelectric device based on enhanced photoelectric recycling effect as claimed in any one of claims 1 to 6, characterized in that: include: S1, growing a bottom battery layer, a highly doped tunnel junction layer and a top battery layer on a substrate in sequence; S2, forming a P-type electrode layer on one side of the substrate by evaporating metal; S3, forming an N-type electrode layer on one side of the top battery layer by using evaporated metal.

8. Use of the optoelectronic device based on enhanced photoelectric recycling effect according to any one of claims 1 to 6 in high-performance optoelectronic devices.

Images