Perovskite type all-optical diode based on nonlinear absorption and preparation method and application thereof

Abstract

The invention provides a nonlinear absorption-based perovskite type all-optical diode which comprises a saturated material and an anti-saturated material, and the nonlinear absorption-based perovskite type all-optical diode is formed by connecting a saturated absorption perovskite material and an anti-saturated absorption perovskite material in series. The perovskite type all-optical diode based on nonlinear absorption has the advantages of being passive, easy to prepare, free of polarization dependence, free of phase matching requirements, adjustable in thickness and small in size, and is more suitable for being used in an integrated optical path. Meanwhile, due to the fact that the band gap of the perovskite material is adjustable, the band gap of the material can be changed by adjusting halide ions, the nonlinear absorption characteristic of the material is further influenced, the all-optical diode suitable for the broadband is achieved, research which is relatively lacked in the wave band of 700-900 nm at present is supplemented, perovskite is applied to non-reciprocal optical devices, and the photoelectric conversion efficiency is improved. And the application range of the perovskite is widened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optoelectronic devices, in particular to a perovskite all-optical diode based on nonlinear absorption and a preparation method and application thereof. BACKGROUND

[0002] The development of modern information technology requires higher miniaturization and integration of devices, and micro-nano photonic devices have incomparable advantages over electronic devices. Non-reciprocal optical devices are a typical micro-nano optical device, in which light propagation does not satisfy the Lorentz reciprocity principle. It is a key element in optical circuits to achieve non-reciprocal transmission of light. Currently, common non-reciprocal optical devices include optical diodes, optical isolators, and optical circulators. Such devices have important applications in optical communication, optical computing, laser systems, and integrated photonics.

[0003] Current research on non-reciprocal optical devices is mainly based on magneto-optical effects, chiral quantum systems, space-time modulation, and nonlinear effects. Among them, magneto-optical effects use magneto-optical materials to change the polarization direction of light to achieve non-reciprocal transmission of light, but there are problems of polarization dependence and strong magnetic field influence, making it difficult to integrate in optical systems. Chiral quantum systems use chiral atoms to respond differently to circularly polarized photons of different spins to achieve non-reciprocal transmission of light, but require high-quality materials and are strongly dependent on resonance. Space-time modulation refers to loading low-frequency time-varying signals discretely on the medium to achieve non-reciprocal transmission of light through modulation signals, but the specific modulation structure and complex device structure limit its development. Non-reciprocal transmission based on nonlinear effects has also been widely studied, including four-wave mixing, self-phase modulation, and nonlinear absorption.

[0004] In the non-reciprocal transmission based on nonlinear effect, four-wave mixing makes the light path meet the forward transmission, and four-wave mixing process occurs, while in the reverse transmission, the phase matching condition is not met, and four-wave mixing process cannot occur. By controlling the phase matching condition in the forward and reverse transmission light, non-reciprocal transmission of light is realized, but there are some shortcomings such as the need for external pump light, the need to meet the phase matching condition, and the large volume which is not conducive to integration. Self-phase modulation refers to when a strong signal light is input into a nonlinear medium, the light intensity of the signal light itself produces a Kerr effect to change the refractive index of the medium, thereby modulating the phase of the signal light itself, and a diffraction ring is produced in the far field. The diffraction pattern intensity caused by self-phase modulation is different when light is shot from the forward and reverse directions. The essence is still to realize the non-reciprocal transmission of light by using the nonlinear absorption difference of the two materials. Nonlinear absorption refers to the case where the absorption coefficient of the medium changes with the light intensity under the action of strong light. When the ground state absorption cross section is greater than the excited state absorption cross section, the absorption coefficient of the medium will decrease with the increase of light intensity, thereby leading to the case that the transmittance increases, which is called saturated absorption (SA). On the contrary, when the ground state absorption cross section is less than the excited state absorption cross section, due to the excited state transition, the net light absorption increases with the input intensity, leading to the case that the light transmission decreases, which is called reverse saturated absorption (RSA). At present, saturated absorption materials have been widely used in laser mode locking, and reverse saturated materials have been widely used in optical limiting devices. Because the nonlinear absorption of the two materials is not completely the same, the transmittance change caused by the light from the forward and reverse directions is different, thereby realizing the non-reciprocal transmission of light. Figure 1 The principle diagram of nonlinear absorption is shown. Among them: Figure 1 (a) shows the change of transmittance of saturated absorption material with light intensity; Figure 1 (b) shows the change of transmittance of reverse saturated absorption material with light intensity; Figure 1 (c) shows the transmission of Gaussian beam in the full optical diode based on the series structure of nonlinear absorption.

[0005] The full optical diode formed by cascading two kinds of materials has the advantages of no strong magnetic field effect, no polarization dependence, and no need to meet the phase matching condition, which has attracted widespread attention of researchers.

[0006] In 2007, Philip et al. used the semiconductor-doped glass as the saturable absorber and copper phthalocyanine as the reverse saturable absorber to form a longitudinal axis asymmetric nonlinear absorption structure, and achieved high nonreciprocal transmission performance. In the forward bias, the light first passed through the SA and then the RSA, and the transmittance increased at high light intensity; in the reverse bias, the light first passed through the RSA and then the SA, and the transmittance decreased at high light intensity, realizing the nonreciprocal transmission of light. After simulation, by changing the nonlinear absorption coefficient and the saturation light intensity, it was found that the transmission of light was reciprocal at low light intensity, and the difference between the forward and reverse transmission of light at high light intensity was affected by the nonlinear absorption parameters. In 2013, Anand et al. reported the first all-carbon solid-state all-optical diode by using graphene and C 60 coated in series. The forward and reverse bias behaviors of the all-optical diode were simulated by numerically solving the corresponding pulse propagation equation, and the nonreciprocal performance was adjusted by adjusting the related parameters such as the saturation light intensity, the effective thickness of the sample, and the nonlinear absorption coefficient. By changing the number of layers of graphene, the nonreciprocal performance of two-layer and few-layer graphene and C 60 coated in series was 3.1 dB and 4.2 dB, respectively, indicating that the nonreciprocal performance could be modulated by the thickness of the sample, and the solid-state micro-nano all-optical diode with adjustable nonreciprocal performance was suitable for integrated optical circuits. Since then, researchers have successively studied some other low-dimensional materials, Dong et al. used Ti3C2T x graphene-like and C 60 coated in series to study the nonreciprocal performance of the all-optical diode, and achieved an adjustable nonreciprocal transmission coefficient of 0.46-4.13 dB by changing the value of x.

[0007] Although the optical isolator prepared by the Faraday magneto-optical effect can achieve good nonreciprocal performance, the strong magnetic field required for the operation of the device will cause the sensitive components in the integrated optical circuit to malfunction, resulting in instability of the entire integrated optical system, and the device has a strong polarization dependence on light. Therefore, in the context of miniaturization and integration of devices, to achieve one-way transmission of light, other nonreciprocal transmission schemes without a magnetic field are needed. Chiral quantum systems usually require high-precision experimental manipulation, including precise control of atomic quantum states, light field polarization states, and microcavity or nanometer structure coupling strength. This highly precise control requirement makes the system structure complex and the experimental technology threshold extremely high, which brings significant challenges to the efficient integration of chiral quantum systems in miniaturized photonic chips. The nonreciprocal transmission scheme based on space-time modulation usually requires specific modulation signals, which has certain requirements for the signal source. Moreover, the device structure is complex and the preparation process is difficult, which is not conducive to mass production. The cascaded all-optical diode based on nonlinear absorption has the advantages of no influence of strong magnetic field, no polarization dependence, and no need to meet the phase matching condition, and many researchers have paid attention to two-dimensional materials including graphene and graphene-like materials, C 60and other noble metal materials with plasmonic resonance characteristics, etc., the research waveband is also concentrated in 532nm, 1064nm and mid-infrared waveband, and the non-reciprocal transmission coefficient is also concentrated in 2-5dB.

[0008] However, the prior art has less research on 700-900nm waveband all-optical diodes, and the prepared all-optical diodes often have defects such as narrow waveband and non-adjustable non-reciprocal transmission performance.

[0009] In summary, a new technical solution is needed to solve the problems in the prior art. SUMMARY

[0010] In view of the defects and deficiencies in the prior art, the present application provides a perovskite all-optical diode based on nonlinear absorption and a preparation method and application thereof. The perovskite all-optical diode based on nonlinear absorption is obtained by placing a saturable absorption perovskite material and an inverse saturable absorption perovskite material in series. The present application is suitable for a wide waveband (700-900nm) and has the characteristics of adjustable non-reciprocal transmission performance, and has good application prospects in optical communication networks and integrated optical circuits.

[0011] One of the objects of the present application is to provide a perovskite all-optical diode based on nonlinear absorption, comprising a saturable material and an inverse saturable material, wherein the perovskite all-optical diode based on nonlinear absorption is formed by placing the saturable material and the inverse saturable material in series;

[0012] wherein,

[0013] The saturable material is a saturable absorption perovskite material.

[0014] The inverse saturable material is an inverse saturable absorption perovskite material.

[0015] Further, the saturable absorption perovskite material of the perovskite all-optical diode based on nonlinear absorption is MAPbI3.

[0016] Further, the perovskite all-optical diode based on nonlinear absorption, wherein the inverse saturable absorption perovskite material is MAPbBr3.

[0017] One of the objects of the present application is to provide a preparation method of the perovskite all-optical diode based on nonlinear absorption, comprising the following steps:

[0018] S1, preparing a saturable absorption perovskite material precursor solution, then spin coating it onto the surface of a substrate, adding an anti-solvent dropwise, then heating on a hot stage to obtain a saturable absorption perovskite film;

[0019] S2, a reverse-saturation-absorption perovskite material precursor solution is prepared, then spin-coated to the surface of a substrate, and a reverse solvent is added dropwise, followed by heating on a hot stage to obtain a reverse-saturation-absorption perovskite film;

[0020] S3, the saturation-absorption perovskite film and the reverse-saturation-absorption perovskite film are connected in series to obtain the nonlinear-absorption-based perovskite all-optical diode.

[0021] Further, in step S1, the spin-coating rotation speed is 1500-3500 rpm, and the time is 30-60 s.

[0022] Further, in step S2, the spin-coating rotation speed is 1500-3500 rpm, and the time is 30-60 s.

[0023] Further, in step S1, the heating temperature is 80-120 DEG C, and the heating time is 5-15 min.

[0024] Further, in step S2, the heating temperature is 80-120 DEG C, and the heating time is 5-15 min.

[0025] Further, the thickness of the saturation-absorption perovskite film is 300-500 nm, and the thickness of the reverse-saturation-absorption perovskite film is 300-500 nm.

[0026] One of the purposes of the present application is that the nonlinear-absorption-based perovskite all-optical diode can be applied in optical communication networks and integrated optical circuits.

[0027] The present application has the following beneficial effects:

[0028] The application provides a perovskite type all-optical diode based on nonlinear absorption, which comprises a saturable material and an anti-saturable material, and is formed by placing the saturable material and the anti-saturable material in series; wherein the saturable material is a saturable absorption perovskite material; and the anti-saturable material is an anti-saturable absorption perovskite material. The perovskite type all-optical diode based on nonlinear absorption has the advantages of passivity, easy preparation, no polarization dependence, no phase matching requirement, adjustable thickness, and small size, and is more suitable for use in an integrated optical circuit than other devices, which are complex, large in size, polarization dependent, and affected by a magnetic field. Meanwhile, since the band gap of the perovskite material is adjustable, the nonlinear absorption characteristics of the material can be further affected by adjusting the halogen ions to change the band gap of the material, so as to realize a wide-band all-optical diode. On the other hand, the application first proposes to realize a full perovskite type all-optical diode by using the large nonlinear absorption and the adjustable band gap of the perovskite, realizes a wide-band all-optical diode, supplements the relatively lack of research in the 700-900 nm waveband, applies the perovskite to a non-reciprocal optical device, and widens the application range of the perovskite. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A principle diagram of nonlinear absorption is shown.

[0030] Wherein:

[0031] Figure 1 (a) shows the change of transmittance of a saturable absorption material with light intensity.

[0032] Figure 1 (b) shows the change of transmittance of an anti-saturable absorption material with light intensity.

[0033] Figure 1 (c) shows the transmission of a Gaussian light beam in the all-optical diode based on the series structure of nonlinear absorption.

[0034] Figure 2 A preparation method diagram of MAPbI3 and MAPbBr3 films in the embodiment is shown.

[0035] Figure 3 A structure diagram of the perovskite type all-optical diode based on nonlinear absorption in the embodiment is shown.

[0036] Figure 4 X-ray diffraction diagrams of MAPbI3 and MAPbBr3 films in the embodiment are shown.

[0037] Wherein:

[0038] Figure 4 (a) shows the X-ray diffraction diagram of the MAPbI3 film in the embodiment.

[0039] Figure 4 (b) shows the X-ray diffraction pattern of the MAPbBr3 thin film in the embodiment.

[0040] Figure 5 The principle diagram of measuring material nonlinear absorption by Z-scan technology and the measurement diagram of different nonlinear absorption (SA and RSA) materials are shown.

[0041] Wherein:

[0042] Figure 5 (a) shows the principle diagram of measuring material nonlinear absorption by Z-scan technology.

[0043] Figure 5 (b) shows the measurement diagram of different nonlinear absorption (SA and RSA) materials.

[0044] Figure 6 The test results of the nonlinear absorption characteristics of the MAPbI3 thin film and the MAPbBr3 thin film in the embodiment are shown.

[0045] Wherein:

[0046] Figure 6 (a) shows the test results of the nonlinear absorption characteristics of the MAPbI3 thin film at 700 nm in the embodiment.

[0047] Figure 6 (b) shows the test results of the nonlinear absorption characteristics of the MAPbI3 thin film at 800 nm in the embodiment.

[0048] Figure 6 (c) shows the test results of the nonlinear absorption characteristics of the MAPbI3 thin film at 900 nm in the embodiment.

[0049] Figure 6 (d) shows the test results of the nonlinear absorption characteristics of the MAPbBr3 thin film at 700 nm in the embodiment.

[0050] Figure 6 (e) shows the test results of the nonlinear absorption characteristics of the MAPbBr3 thin film at 800 nm in the embodiment.

[0051] Figure 6 (f) shows the test results of the nonlinear absorption characteristics of the MAPbBr3 thin film at 900 nm in the embodiment.

[0052] Figure 7 The test results of the non-reciprocal performance of the perovskite all-optical diode based on nonlinear absorption in the embodiment are shown.

[0053] Wherein:

[0054] Figure 7 (a) shows the non-reciprocal performance test results of the perovskite type all-optical diode based on nonlinear absorption at 700 nm in the embodiment;

[0055] Figure 7 (b) shows the non-reciprocal performance test results of the perovskite type all-optical diode based on nonlinear absorption at 800 nm in the embodiment;

[0056] Figure 7 (c) shows the non-reciprocal performance test results of the perovskite type all-optical diode based on nonlinear absorption at 900 nm in the embodiment. DETAILED DESCRIPTION

[0057] In order to more clearly illustrate the technical solutions of the present application, the following examples are listed. The raw materials, reactions and post-processing means appearing in the examples are all common raw materials on the market and technical means well known to those skilled in the art, unless otherwise stated.

[0058] The words "preferred", "preferably", "more preferred" and the like in the present specification mean that in certain circumstances, certain embodiments of the application can provide certain benefits, however, other embodiments can also be preferred under the same or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not useful, nor does it imply that these other embodiments are excluded from the scope of the application.

[0059] It should be understood that, except in any operating examples, or where otherwise indicated, expressions of amount or all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending on the desired properties sought to be obtained by the present application.

[0060] To determine the optimal material system of the present application, the generalized pulse propagation equation of the third-order nonlinear absorption is analyzed by MATLAB parameter fitting, and the results show that the nonlinear absorption coefficient, sample thickness and saturation light intensity will significantly affect the performance of the all-optical diode, and the calculation method is shown in formula (1). Based on the above analysis, considering that the perovskite material has a large nonlinear coefficient, and the band gap can be flexibly adjusted by adjusting the halogen ion, the present application selects organic-inorganic perovskite MAPbI3 and MAPbBr3 film to form a full perovskite type all-optical diode.

[0061]

[0062] wherein,

[0063] a0 is the linear absorption coefficient, β is the nonlinear absorption coefficient, I S is the saturation light intensity, and I(z) is the light intensity of the light beam at the z position.

[0064] Embodiment

[0065] A nonlinear absorption-based perovskite photodiode, comprising a saturable material and an unsaturable material, the nonlinear absorption-based perovskite photodiode being formed by placing the saturable material and the unsaturable material in series;

[0066] wherein,

[0067] The saturable material is MAPbI3.

[0068] The unsaturable material is MAPbBr3.

[0069] A preparation method of the nonlinear absorption-based perovskite photodiode comprises the following steps:

[0070] S1, 0.1589 g (1 mmol) of methylammonium iodide (MAI) and 0.4610 g (1 mmol) of lead iodide (PbI2) are weighed, and 1 mL of N,N-dimethylformamide (DMF) is extracted by a pipette. MAI and PbI2 are dissolved in DMF, the molar ratio of MAI and PbI2 is 1:1, a solution of 1 mol / L MAPbI3 is prepared, and a magnetic stirrer is used to stir at room temperature for 4 h to ensure that all solid powder crystals are completely dissolved in DMF; finally, a PTFE filter with a pore size of 0.22 μm is used to filter the completely dissolved precursor solution to obtain a MAPbI3 precursor solution, the MAPbI3 precursor solution is spin-coated on a glass substrate at a rotation speed of 2500 rpm for 40 s, 200 μL of toluene (analytical pure, content ≥ 99.5%, purchased from Guangdong Guangshi Reagent Technology Co., Ltd.) is added as an anti-solvent, and then transferred to a hot stage with a temperature of 100 ℃ for heating for 10 min to obtain a MAPbI3 thin film;

[0071] S2, 0.1109 g (1 mmol) of methyl ammonium bromide (MABr) and 0.3670 g (1 mmol) of lead bromide (PbBr2) were weighed, and 0.8 mL of DMF and 0.2 mL of dimethyl sulfoxide (DMSO) were extracted by a pipette. MABr and PbBr2 were dissolved in the mixture of DMF and DMSO, the molar ratio of MABr and PbBr2 was 1:1, a solution of 1 mol / L MAPbBr3 was prepared, and a magnetic stirrer was used to stir at room temperature for 4 h to ensure that all the solid powder crystals were completely dissolved in the DMF / DMSO mixture; finally, a PTFE filter with a pore size of 0.22 μm was used to filter the completely dissolved precursor solution to obtain a MAPbBr3 precursor solution, 200 μL of toluene (analytical pure, content ≥ 99.5%, purchased from Guangdong Guangshi Reagent Technology Co., Ltd.) was added as an anti-solvent, and then transferred to a hot stage with a temperature of 100 ℃ for heating for 10 min to obtain a MAPbBr3 thin film;

[0072] S3, the MAPbI3 thin film and the MAPbBr3 thin film were placed in series to obtain the nonlinear absorption-based perovskite photodiode.

[0073] Figure 2 The preparation method of the MAPbI3 thin film and the MAPbBr3 thin film in the embodiment is shown in the schematic diagram.

[0074] Figure 3 The structure of the nonlinear absorption-based perovskite photodiode in the embodiment is shown in the schematic diagram.

[0075] The two perovskite thin films were analyzed by X-ray diffraction technology, and the results are shown in Figure 4 . Figure 4 The X-ray diffraction patterns of the MAPbI3 thin film and the MAPbBr3 thin film in the embodiment are shown in the schematic diagram; wherein: Figure 4 (a) shows the X-ray diffraction pattern of the MAPbI3 thin film in the embodiment; Figure 4 (b) shows the X-ray diffraction pattern of the MAPbBr3 thin film in the embodiment. As can be seen from the figure, there is no obvious impurity peak in the figure, the main diffraction peak intensity is large, the full width at half maximum (FWHM) of the diffraction peak is narrow, there is no obvious impurity peak, and the crystallization effect is good. It is shown that the two prepared perovskite thin films have good effects.

[0076] Z-scan technology is the simplest method for measuring nonlinear absorption of materials. The Z-scan technology measures the nonlinear absorption of materials mainly by using two-lens confocal, and the sample moves in the one-dimensional Z-axis direction. The measurement of nonlinear absorption and nonlinear refractive signals is realized by opening and closing the aperture in front of the detector. When the aperture is opened, the nonlinear absorption characteristics of the material can be measured. When the sample moves from -z to z, as the light intensity gradually increases, if its absorption decreases and the transmission increases, the output energy curve is a symmetrical peak, indicating that the sample exhibits a saturated absorption effect. Conversely, if it is a symmetrical trough, it represents an anti-saturation effect. Figure 5 The method for measuring the nonlinear absorption of materials by Z-scan technology is shown in the schematic diagram and the measurement schematic diagram of different nonlinear absorption (SA and RSA) materials. Figure 5 (a) shows the principle schematic diagram of measuring the nonlinear absorption of materials by Z-scan technology. Figure 5 (b) shows the measurement schematic diagram of different nonlinear absorption (SA and RSA) materials.

[0077] We tested the MAPbI3 film and the MAPbBr3 film by using femtosecond laser. The test results are shown in Figure 6 .

[0078] Figure 6 The test results of the nonlinear absorption characteristics of the MAPbI3 film and the MAPbBr3 film in the embodiment are shown. Among them: Figure 6 (a) shows the test results of the nonlinear absorption characteristics of the MAPbI3 film at 700 nm in the embodiment. Figure 6 (b) shows the test results of the nonlinear absorption characteristics of the MAPbI3 film at 800 nm in the embodiment. Figure 6 (c) shows the test results of the nonlinear absorption characteristics of the MAPbI3 film at 900 nm in the embodiment. Figure 6 (d) shows the test results of the nonlinear absorption characteristics of the MAPbBr3 film at 700 nm in the embodiment. Figure 6 (e) shows the test results of the nonlinear absorption characteristics of the MAPbBr3 film at 800 nm in the embodiment. Figure 6 (f) shows the test results of the nonlinear absorption characteristics of the MAPbBr3 film at 900 nm in the embodiment. As can be seen from the figure, the MAPbI3 film exhibits a saturated absorption effect at 700 nm, 800 nm and 900 nm, while the MAPbBr3 film exhibits an anti-saturation absorption effect, so it can be composed into a full perovskite full optical diode.

[0079] Test Example

[0080] The nonlinear absorption based perovskite all-optical diode prepared in the embodiment is subjected to nonreciprocal performance test.

[0081] Test method:

[0082] The Z-scan technique is used to test the nonreciprocal performance of the embodiment.

[0083] The test results are shown in Figure 7 .

[0084] Figure 7 The nonreciprocal performance test results of the nonlinear absorption based perovskite all-optical diode in the embodiment are shown; wherein: Figure 7 (a) shows the nonreciprocal performance test results of the nonlinear absorption based perovskite all-optical diode in the embodiment at 700 nm; Figure 7 (b) shows the nonreciprocal performance test results of the nonlinear absorption based perovskite all-optical diode in the embodiment at 800 nm; Figure 7 (c) shows the nonreciprocal performance test results of the nonlinear absorption based perovskite all-optical diode in the embodiment at 900 nm. As can be seen from the figure, the nonlinear absorption based perovskite all-optical diode of the embodiment achieves a nonreciprocal performance of 6.2 dB at 700 nm. At the same time, since the two materials also have good nonlinear absorption characteristics at 800 nm and 900 nm, the device has good nonreciprocal performance in the 700-900 nm waveband.

[0085] In the MAPbX3 material, MAPbBr3 is a desaturated material, and MAPbI3 is a saturated material, and the band gap can be changed by adjusting the halogen ion, thereby affecting the nonlinear absorption characteristics of the material. The present application first proposes to use the large nonlinear absorption and band gap adjustable characteristics of perovskite to construct a full perovskite all-optical diode. With the wide waveband response characteristics of the perovskite sample itself, a perovskite all-optical diode in the 700-900 nm waveband is realized. In addition, by adjusting the related parameters of the perovskite material, the performance of the full perovskite all-optical diode based on nonlinear absorption of the present application can be further changed.

[0086] It is apparent for those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and the present application can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, and the scope of the present application is defined by the appended claims rather than the foregoing description, and it is intended to embrace all changes falling within the meaning and scope of equivalents of the claims.

[0087] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature described. The specification can include implicit combinations of explicitly mentioned features and / or explicit combinations of implicitely mentioned features. Each embodiment depends on the explicit combinations of features and / or the implicit combinations of features made specifically within that embodiment, and each such embodiment can be combined with every other such embodiment to create further embodiments.

Claims

1. A perovskite-type all-optical diode based on nonlinear absorption, comprising a saturated material and an anti-saturated material, characterized in that, The perovskite-type all-optical diode based on nonlinear absorption is formed by placing saturated and anti-saturated materials in series. in, The saturated material is a saturated absorber perovskite material; The antisaturated material is an antisaturated absorber perovskite material.

2. The perovskite-type all-optical diode based on nonlinear absorption according to claim 1, characterized in that, The saturated absorber perovskite material is MAPbI3.

3. The perovskite-type all-optical diode based on nonlinear absorption according to claim 1, characterized in that, The anti-saturated absorber perovskite material is MAPbBr3.

4. The method for fabricating a perovskite-type all-optical diode based on nonlinear absorption as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Prepare a saturated absorber perovskite material precursor solution, spin-coat it onto the substrate surface, add antisolvent, and then heat it on a hot stage to obtain a saturated absorber perovskite film. S2. Prepare a reverse saturated absorber perovskite material precursor solution, spin-coat it onto the substrate surface, add antisolvent, and then heat it on a hot stage to obtain a reverse saturated absorber perovskite film. S3. The saturated absorption perovskite film and the anti-saturated absorption perovskite film are connected in series to obtain the perovskite-type all-optical diode based on nonlinear absorption.

5. The method for fabricating a perovskite-type all-optical diode based on nonlinear absorption according to claim 4, characterized in that, In step S1, the spin coating speed is 1500-3500 rpm and the time is 30-60 s.

6. The method for fabricating a perovskite-type all-optical diode based on nonlinear absorption according to claim 4, characterized in that, In step S2, the spin coating speed is 1500-3500 rpm and the time is 30-60 s.

7. The method for fabricating a perovskite-type all-optical diode based on nonlinear absorption according to claim 4, characterized in that, In step S1, the heating temperature is 80-120℃ and the heating time is 5-15 minutes.

8. The method for fabricating a perovskite-type all-optical diode based on nonlinear absorption according to claim 4, characterized in that, In step S2, the heating temperature is 80-120℃ and the heating time is 5-15 minutes.

9. The method for fabricating a perovskite-type all-optical diode based on nonlinear absorption according to claim 4, characterized in that, The thickness of the saturated absorption perovskite film is 300-500 nm; the thickness of the anti-saturated absorption perovskite film is 300-500 nm.

10. The application of the perovskite all-optical diode based on nonlinear absorption as described in any one of claims 1-3 in optical communication networks and integrated optical circuits.

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