A charge transfer state-mediated infrared light-gated hybrid perovskite material with wide spectral response and a preparation method and application thereof

Abstract

The application discloses a kind of hybrid perovskite materials based on charge transfer state mediation infrared light gate control wide spectrum response and its preparation method and application, belong to photoelectric functional material technical field.The technical scheme of the present application introduces strong electron-withdrawing, photochromic active pyridinium cation into 0~3 dimensional metal halide perovskite structure to construct an intermediate band near the bottom of inorganic conduction band, which is formed by the low-lying orbit of organic cation.Under UV / vis light pumping, electrons are first excited from the valence band to the conduction band, and then rapidly transferred to the intermediate band, forming a charge transfer state (CT state) with a lifetime of nanoseconds.On the basis of this pre-filled CT state, the electrons are lifted back to the conduction band using infrared single-photon excitation, achieving single-photon infrared photoresponse below the band gap, thereby expanding the effective response band of the photodetector to at least 7 μm.

Description

Technical Field

[0001] This application relates to an infrared-gated broadband spectral-responsive hybrid perovskite material based on charge-transfer state mediation, its preparation method and application, belonging to the field of optoelectronic functional materials technology. Background Technology

[0002] Broadband photodetectors, covering the ultraviolet (UV), visible (vis), and infrared (IR) bands, are of great significance for efficient solar energy utilization, optical communication, and multispectral imaging. In the solar spectrum, short-wave infrared (SWIR, 1–2.5 μm) contributes approximately 20–25% of the irradiance energy, while most existing photovoltaic and photodetectors primarily utilize UV-vis photons, neglecting the low-energy IR photons.

[0003] On the one hand, mainstream wide-bandgap photovoltaic absorbers such as crystalline silicon (Eg≈1.1 eV), GaAs (Eg≈1.42 eV), CdTe (Eg≈1.5 eV), and typical three-dimensional hybrid perovskites (such as MAPbI3, Eg≈1.5~1.6 eV) are difficult to absorb long-wave infrared photons with band gaps higher than their band gaps in single-junction devices. On the other hand, although narrow-bandgap semiconductors (such as InGaAs, HgCdTe, InSb) can extend the response to the mid-infrared and even far-infrared, they generally suffer from serious thermal noise, require deep cooling, have high manufacturing costs and complex processes, and inherently limit the open-circuit voltage in photovoltaic applications.

[0004] Nonlinear processes such as multiphoton absorption can theoretically overcome the bandgap limitation, but their quantum efficiency is extremely low under natural light intensity, making them impractical. Therefore, a new mechanism is urgently needed to enable wide-bandgap semiconductors to achieve efficient response to single-photon IR energies smaller than the bandgap while maintaining low thermal noise and high voltage potential. Summary of the Invention

[0005] To address the challenges of effectively utilizing IR photons, achieving low thermal noise, and low cost in existing optoelectronic materials technologies within a single bandgap semiconductor, this application provides a charge-transfer state-mediated infrared-gated broadband response hybrid perovskite material technology. This technology utilizes a charge-transfer prepopulation (CTP) strategy to achieve a single-photon infrared-gated broadband response optoelectronic material system within a single broadband metal halide perovskite. Specifically, it involves introducing strongly electron-withdrawing and photochromic pyridinium cations into the 0-3D metal halide perovskite structure to construct an intermediate band near the inorganic conduction band bottom, formed by low-altitude orbitals of organic cations. Under UV / vis light pumping, electrons are first excited from the valence band to the conduction band, and then ultrafastly transferred to the intermediate band to form a charge-transfer state (CT state) with a lifetime on the order of nanoseconds. Based on this pre-filled CT state, the electrons are then lifted back to the conduction band by infrared single-photon excitation, realizing a single-photon infrared photoelectric response below the band gap, thereby extending the effective response band of the photodetector to at least 7 μm.

[0006] The technical solution adopted in this application is as follows: According to a first aspect of this application, a charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite material is provided, comprising a hybrid metal halide structure with the general chemical formula A. a M b X c ; Wherein, A is a positively charged organic cation, and the positively charged organic cation contains at least one heteroazo aromatic ring with an electronic defect; M is a metal cation; X is a halide anion; a, b, and c are positive integers whose values ​​satisfy the overall charge neutrality.

[0007] Optionally, the hybrid metal halide structure includes organic and inorganic components; The organic component is fixed to the interstitial space of the inorganic component through at least one of electrostatic interaction, hydrogen bonding, and van der Waals interaction. The layer is composed of A, and its lowest unoccupied molecular orbital is located in the energy level range ΔE below the conduction band bottom of the inorganic component, 0.05 eV ≤ ΔE ≤ 1.0 eV.

[0008] The inorganic component is a metal halide composed of M and X, which has at least one of a zero-dimensional discrete cluster structure, a one-dimensional chain structure, a two-dimensional layered structure, or a three-dimensional continuous framework structure.

[0009] Optionally, the zero-dimensional discrete cluster structure is a zero-dimensional perovskite structure composed of discrete metal halide clusters, wherein the discrete metal halide clusters are completely separated by A and there is no direct metal halide connection between them. Optionally, the one-dimensional chain structure is a one-dimensional chain composed of metal halide coordination polyhedra that share corners, edges, or faces.

[0010] Optionally, the two-dimensional layered structure is a layered inorganic network composed of metal halide coordination polyhedra with shared corners or edges, wherein A serves as a spacer layer to separate the inorganic components along the c-axis, forming a quantum well-type Ruddlesden–Popper structure.

[0011] Optionally, the three-dimensional continuous framework structure is a three-dimensional perovskite framework composed of angle-shared metal halide octahedra, wherein part or all of the A sites occupy the A sites and introduce the intermediate zone.

[0012] Optionally, the heteroacidic aromatic ring of the electron defect is selected from at least one of pyridinium cations, bipyridinium cations, hydrazine-coupled pyridinium cations, bipyridine cations, viologen cations, and strong electron-withdrawing organic cations.

[0013] Optionally, the pyridinium cation is obtained by halogenation, protonation or quaternization of an organic amine or polyamine containing a pyridine ring.

[0014] Optionally, the bipyridinium cation is obtained by protonation or quaternization of a bipyridine or bispyridine skeleton formed by coupling two pyridine rings.

[0015] Optionally, the hydrazine-coupled pyridinium cation is obtained by protonation of a hydrazine-bridged bispyridine skeleton.

[0016] Optionally, the electronically defective heteroazo aromatic ring is obtained by conjugating a heteroazo aromatic ring fragment containing a biaryl, diazine, triazine, or naphthidine with a pyridine ring.

[0017] Optionally, M is a positively valent metal cation.

[0018] Optionally, the metal element in the metal cation is selected from at least one of Pb, Sn, Ge, Mn, Cu, Bi, and Ag.

[0019] Optionally, X is selected from Cl — ,Br — I — At least one of them.

[0020] According to a second aspect of this application, a method for preparing infrared-gated broadband spectral-responsive hybrid perovskite materials mediated by charge transfer states is provided, comprising: According to the general chemical formula A a M b X c In a stoichiometric ratio of a, an organic amine ligand containing at least one electron defect of a heteroazo aromatic ring is mixed with a haloic acid solution to obtain the corresponding organic halide solution. According to the general chemical formula A a M b X c The metal halide is mixed with the organic halide salt in a stoichiometric ratio of b to obtain a precursor solution. The precursor solution is then crystallized to obtain the infrared-gated broadband spectral response hybrid perovskite material mediated by charge transfer state.

[0021] Optionally, the organic amine ligand containing at least one electron defect of a heteroazo aromatic ring is selected from at least one organic amine ligand containing a pyridine, bipyridine, hydrazine-coupled pyridine, or viologen skeleton.

[0022] The crystallization method is selected from one of solution cooling crystallization, solvent evaporation crystallization, antisolvent-induced crystallization, or spin coating-annealing.

[0023] According to a third aspect of this application, an infrared-gated broadband response photodetector is provided, comprising a photoelectric material and a first electrode and a second electrode disposed opposite to and connected to both sides of the photoelectric material; The optoelectronic material is selected from at least one of the aforementioned charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite materials or the charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite materials prepared according to the aforementioned preparation method.

[0024] Optionally, under conditions without ultraviolet and / or visible light pre-excitation, the infrared-gated broadband response photodetector does not produce a photoelectric response to infrared light located below the intrinsic bandgap of the photoelectric material; Under conditions of UV and / or visible light pre-excitation, the infrared-gated broadband response photodetector produces a single-photon, near-linear photoelectric response to at least a portion of infrared light in the 300 nm to 7 μm band.

[0025] Optionally, the infrared-gated broadband response photodetector has a sandwich structure formed by a planar first electrode, a single crystal or thin film of the photoelectric material, and a planar second electrode.

[0026] Optionally, the first electrode and the second electrode are Ag.

[0027] Optionally, the photoelectric material is selected from (HEAP)PbI4, (H2APD)PbI4, and (AeMV)2Pb3I. 12One or a combination thereof, wherein (HEAP)PbI4 and (H2APD)PbI4 are two-dimensional perovskites, and (AeMV)2Pb3I 12 It is a zero-dimensional perovskite.

[0028] According to the fourth aspect of this application, at least one of the aforementioned charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite material or the charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite material prepared according to the aforementioned preparation method is provided for use in broadband photodetectors, infrared-gated imaging devices, optical communication receivers, solar infrared energy harvesters, or multispectral sensors.

[0029] The beneficial effects of this application include: (1) Realizing single-photon infrared collection in a single wide-bandgap semiconductor By employing the CTP strategy, this application constructs a controllable intermediate band and a long-lived CT state in a large-bandgap perovskite, achieving single-photon IR excitation below the bandgap. This enables wide-bandgap materials to obtain infrared response capabilities similar to narrow-bandgap materials while maintaining low thermal noise and high voltage potential.

[0030] (2) The effective response band extends to at least 7 μm Based on the energy level shift of approximately 0.1 eV between the CT band and the conduction band bottom, the theoretical absorption limit of the material in this application can be extended to approximately 7~9 μm. After device design and structural optimization, the photodetector can maintain measurable and effective photoelectric response in the 0.3~9 μm band, realizing true "UV-IR" broadband detection.

[0031] (3) Linear infrared photoelectric response and infrared gating mechanism Under continuous UV / vis pre-excitation conditions, the device of this application exhibits an approximately linear light intensity-current relationship (exponent n≈1) for 980, 2200, and 7000 nm infrared light, which is significantly different from the high-order nonlinear characteristics of multiphoton absorption. This proves that it is a single-photon triggered CT state dissociation process, realizing controllable "infrared gating" switching behavior, which is beneficial for signal amplification. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the zero-dimensional crystal structure of the infrared-gated broadband spectral response hybrid perovskite material of this application. The organic component of the crystal is based on a heteroazo aromatic ring, and the organic and inorganic components are combined through hydrogen bonds (red dashed line). Figure 2This is a schematic diagram of the one-dimensional crystal structure of the infrared-gated broadband spectral response hybrid perovskite material of this application. The organic component of the crystal is based on a heteroazo aromatic ring. The organic component is positively charged and the inorganic component is negatively charged. The organic and inorganic components are combined through electrostatic interaction forces. Figure 3 This is a schematic diagram of the two-dimensional crystal structure of the infrared-gated broadband spectral response hybrid perovskite material of this application. The organic component of the crystal is based on a heteroazo aromatic ring. Figure 4 This is a schematic diagram of the energy level structure of the infrared-gated broadband spectral response hybrid perovskite material of this application, showing the valence band, conduction band, and charge transfer intermediate band formed by organic cations and their excitation process; Figure 5 This is a schematic diagram illustrating the working principle of infrared detection achieved by the infrared-gated broadband spectral response hybrid perovskite material under ultraviolet / visible light excitation conditions in this application. Figure 6 The current-voltage (I–V) characteristic curves of the optoelectronic device prepared for the example under different illumination conditions are shown below. The black curve represents the device current under dark conditions; the gray curve represents the device current under xenon lamp near-infrared light (λ>800 nm) illumination conditions; the hollow blue curve represents the device current under 520 nm visible light illumination conditions; and the solid blue curve represents the device current under simultaneous 520 nm visible light and near-infrared light (λ>800 nm) illumination conditions.

[0033] Figure 7 The current-voltage (I–V) response curves of the optoelectronic device under different illumination conditions are shown in the example. Wherein: the black curve represents dark conditions; the gray curve represents 2200 nm infrared light illumination conditions; the hollow purple curve represents ultraviolet-visible light (λ<420 nm) illumination conditions; and the solid purple curve represents simultaneous ultraviolet-visible light (λ<420 nm) and 2200 nm infrared light illumination conditions.

[0034] Figure 8 The figure shows the photocurrent response curve of the optoelectronic device under 980 nm infrared light pulse irradiation. In the figure: the upper green curve represents the change in photocurrent at 980 nm under continuous excitation with 520 nm visible light; the middle blue curve represents the change in photocurrent at 980 nm under continuous excitation with 375 nm ultraviolet light; the lower gray curve represents the change in photocurrent at 980 nm without additional light excitation. The red shaded areas represent the periodic irradiation intervals of 980 nm infrared light, corresponding to optical powers of 0.92 mW, 1.59 mW, 2.17 mW, and 2.78 mW, respectively.

[0035] Figure 9The figure shows the photocurrent response curve of the optoelectronic device under 2200 nm mid-infrared light irradiation conditions. In the figure: the upper green curve represents the change in photocurrent at 2200 nm under continuous excitation with 520 nm visible light; the middle blue curve represents the change in photocurrent at 2200 nm under continuous excitation with 375 nm ultraviolet light; the lower gray curve represents the change in photocurrent at 2200 nm under no additional light excitation conditions. The purple shaded areas represent the periodic irradiation intervals of 2200 nm infrared light, corresponding to light powers of 0.11 mW, 0.23 mW, 0.33 mW, and 0.48 mW, respectively. Detailed Implementation

[0036] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0037] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0038] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.

[0039] The purpose of this invention is to provide an optoelectronic material system that utilizes a charge transfer pre-filling strategy to achieve single-photon infrared-gated broadband response in a single wide-bandgap metal halide perovskite, overcoming the problems of existing technologies such as wide-bandgap materials being difficult to effectively utilize IR photons, and narrow-bandgap materials having high thermal noise and high preparation costs.

[0040] By introducing strongly electron-withdrawing and photochromic pyridinium cations into 0- to 3D metal halide perovskite structures, this invention constructs an intermediate band near the inorganic conduction band bottom, formed by low-altitude orbits of organic cations. Under UV / vis light pumping, electrons are first excited from the valence band to the conduction band, and then ultrafastly transfer to this intermediate band, forming a CT state with a lifetime on the order of nanoseconds. Based on this pre-filled CT state, infrared single-photon excitation is used to lift electrons back to the conduction band, achieving a single-photon infrared photoelectric response below the band gap, thereby extending the effective response band of the photodetector to at least 7 μm.

[0041] According to one embodiment of this application, a charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite material includes a hybrid metal halide structure with the general chemical formula A. a M b X c ; Wherein, A is a positively charged organic cation, and the positively charged organic cation contains at least one hetero-nitrogen aromatic ring with an electronic defect; M is a metal cation; X is a halide anion; a, b, and c are positive integers whose values ​​satisfy the overall charge neutrality.

[0042] In one embodiment, the hybrid metal halide structure includes organic and inorganic components; The organic component is fixed to the interstitial space of the inorganic component through at least one of electrostatic interaction, hydrogen bonding, and van der Waals interaction. The layer is composed of A, whose lowest unoccupied molecular orbital is located in the energy range ΔE below the conduction band bottom of the inorganic component, 0.05 eV ≤ ΔE ≤ 1.0 eV. The organic cation A forms an intermediate band in the crystal with a certain energy below the inorganic conduction band bottom (forming a CT band after UV / Vis excitation). This structure allows charge transfer from the inorganic sublattice to A under UV / Vis irradiation, forming a nanosecond-level long-lived charge transfer state (CT state), and constituting a metastable state (CT band) within the band gap of the material. The energy level shift of the CT band relative to the conduction band bottom of the inorganic component satisfies the above-mentioned ΔE range. Under continuous or pulsed UV / Vis irradiation, infrared irradiation can further excite the pre-filled electrons in the CT band into the conduction band of the inorganic component by a single infrared photon, thereby achieving a metastable state (CT band) within the wide band gap of A. a M b X c Achieving single-photon, linear infrared photoelectric response in materials; In one embodiment, the range of ΔE is preferably 0.1 eV to 0.3 eV, so as to achieve an efficient and linear infrared single-photon response while maintaining a wide bandgap in the material.

[0043] The inorganic component is a metal halide composed of M and X, which has at least one of a zero-dimensional discrete cluster structure, a one-dimensional chain structure, a two-dimensional layered structure, or a three-dimensional continuous framework structure.

[0044] In one embodiment, the inorganic component is selected from at least one of the following: a zero-dimensional discrete metal halide cluster formed by M and X, a one-dimensional metal halide chain, a two-dimensional layered network of metal halide, and a three-dimensional metal halide framework.

[0045] However, existing work largely focuses on white light emission, X-ray detection, or surface defect state manipulation. Research on how to achieve single-photon infrared collection while maintaining a wide bandgap and extending the response band to 2 μm or even 7 μm remains very limited. Metal halide perovskites, especially two-dimensional and low-dimensional perovskites, possess designable organic-inorganic hybrid frameworks and strong exciton effects. This application constructs a controllable intermediate band within the bandgap by introducing appropriate electron-withdrawing groups into the organic component, achieving sub-bandgap absorption and charge transfer. This allows the infrared-gated broadband response hybrid perovskite material based on charge transfer state mediation to maintain a large bandgap, low thermal noise, and high open-circuit voltage potential while extending the light absorption and photoelectric response range from ultraviolet-visible to short-wave infrared and even mid-infrared. Devices using this material can achieve effective photoelectric detection responses in the 0.3–9 μm band, making them suitable for broadband light detection, infrared-gated imaging, and solar infrared energy harvesting. In one embodiment, the zero-dimensional discrete cluster structure is a zero-dimensional perovskite-like structure composed of discrete metal halide clusters, wherein the discrete metal halide clusters are completely separated by A and have no direct metal halide connections between them. For example, the discrete metal halide clusters are Pb3X. 12 ; In one embodiment, the one-dimensional chain structure is a one-dimensional chain composed of metal halide coordination polyhedra that share corners, edges, or faces. For example, the discrete metal halide cluster is MX6.

[0046] In one embodiment, the two-dimensional layered structure is a layered inorganic network composed of metal halide coordination polyhedra with shared corners or edges, wherein A serves as a spacer layer to separate the inorganic components along the c-axis direction, forming a quantum well-type Ruddlesden-Popper structure. For example, the metal halide is MX6.

[0047] In one embodiment, the three-dimensional continuous framework structure is a three-dimensional perovskite framework composed of corner-shared metal halide octahedra, wherein the A portion or all occupies the A site and introduces the intermediate zone; exemplarily, the metal halide is configured as MX6.

[0048] In one embodiment, the heteroacidic aromatic ring of the electronic defect is selected from at least one of pyridinium cations, bipyridinium cations, hydrazine-coupled pyridinium cations, bipyridinium cations, and viologen cations.

[0049] In one embodiment, the pyridinium cation is obtained by protonation or quaternization of an organic amine or polyamine containing a pyridine ring via a halogenated acid. The organic amine can be linked to an amino group via a carbon chain such as methylene, ethyl, or propyl, exemplarily forming N-(ethylamino)pyridinium (HEAP). 2+ ) and other cations.

[0050] In one embodiment, the bipyridine-onium cation is obtained by protonation or quaternization of a bipyridine or bispyridine skeleton formed by coupling two pyridine rings. Exemplarily, the bipyridine-onium cation can be 4,4′-bipyridine, 1-methyl-1′-aminoethyl-4,4′-bipyridine cation (AeMV). 2+ ) and its substitutes.

[0051] In one embodiment, the hydrazopyridinium-coupled cation is obtained by protonation of a hydrazine-bridged bispyridine skeleton; exemplarily, the hydrazopyridinium-coupled cation is 4,4′-hydrazopyridinium (APD). 2+ ) and its derivatives.

[0052] In one embodiment, the electron-defect heteroazo aromatic ring is obtained by conjugating a heteroazo aromatic ring fragment containing a biaryl, diazine, triazine, or naphthidine with a pyridine ring.

[0053] In one embodiment, M is a positively charged metal cation, and M is preferably a divalent metal cation.

[0054] In one embodiment, the metal element in the metal cation is selected from at least one of Pb, Sn, Ge, Mn, Cu, Bi, and Ag.

[0055] In one embodiment, X is selected from Cl — ,Br — I — At least one of them.

[0056] According to one embodiment of this application, a method for preparing a charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite material includes: According to the general chemical formula A a M b X c The organic amine ligand containing at least one electron defect of a heteroazo aromatic ring is mixed with a haloic acid solution in a stoichiometric ratio of a to obtain the corresponding organic halide salt solution. The choice of solvent and the range of solute concentration in the organic halide salt solution are not strictly limited and can be selected as needed. The ratio of organic amine ligand to haloic acid solution is not strictly limited and can be selected as needed.

[0057] According to the general chemical formula A a M b X c The metal halide is mixed with the organic halide salt according to the stoichiometric ratio of b to obtain a precursor solution. The precursor solution is then crystallized to obtain the precursor solution of the charge-transfer state-mediated infrared-gated broadband spectral response hybrid perovskite material. The solvent selection and solute concentration range in the precursor solution are not strictly limited and can be selected as needed.

[0058] In one embodiment, the organic amine ligand containing at least one electron defect of a heteroazo aromatic ring is selected from at least one organic amine ligand containing a pyridine, bipyridine, hydrazine-coupled pyridine, or viologen skeleton; The crystallization method is selected from one of solution cooling crystallization, solvent evaporation crystallization, antisolvent-induced crystallization, or spin coating-annealing.

[0059] According to one embodiment of this application, an infrared-gated broadband response photodetector includes a photoelectric material and a first electrode and a second electrode disposed opposite to and connected to both sides of the photoelectric material. The optoelectronic material is selected from at least one of the aforementioned charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite materials or the charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite materials prepared according to the aforementioned preparation method.

[0060] In one embodiment, under conditions without ultraviolet and / or visible light pre-excitation, the infrared-gated broadband response photodetector does not produce a photoelectric response to infrared light located below the intrinsic bandgap of the photoelectric material; Under conditions of UV and / or visible light pre-excitation, the infrared-gated broadband response photodetector produces a single-photon, near-linear photoelectric response to at least a portion of infrared light in the 300 nm to 7 μm band.

[0061] In one embodiment, under continuous ultraviolet and / or visible light pre-excitation conditions, the infrared-gated broadband response photodetector has a measured linear photoelectric response in the 300 nm to 2200 nm band and maintains a measurable photoelectric response signal in the 2200 nm to 7000 nm band, with an overall effective photoelectric detection band coverage of 0.3 to 7 μm.

[0062] In one embodiment, the infrared-gated broadband response photodetector has a sandwich structure formed by a planar first electrode, a single crystal or thin film of the photoelectric material, and a planar second electrode.

[0063] In one embodiment, the first electrode and the second electrode are Ag.

[0064] In one embodiment, the photoelectric material is selected from (HEAP)PbI4, (H2APD)PbI4, and (AeMV)2Pb3I. 12 One or a combination thereof, wherein (HEAP)PbI4 and (H2APD)PbI4 are two-dimensional perovskites, and (AeMV)2Pb3I 12 It is a zero-dimensional perovskite.

[0065] According to one embodiment of this application, at least one of the aforementioned charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite material or the charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite material prepared according to the aforementioned preparation method is applied in a broadband photodetector, an infrared-gated imaging device, an optical communication receiver, a solar infrared energy harvester, or a multispectral sensor.

[0066] In the above applications, for infrared-gated broadband spectral response hybrid perovskite materials based on charge transfer state mediation, the CT band can be pre-excited and filled with ultraviolet / visible light, and the CT state charge separation and carrier generation can be triggered by infrared light to realize single-photon infrared collection and signal amplification in wide-bandgap semiconductors.

[0067] Example 1: Preparation of (MIQ)PbI3 single crystal material Methylisoquinoline (MIQ, 0.1 mmol, approximately 14 mg) was dissolved in 4 mL of hydroiodic acid solution (HI, 45–55 wt%) and reacted at room temperature for 10 min under magnetic stirring to obtain a methylisoquinoline iodide (MIQI) solution. Separately, lead iodide (PbI2, 0.1 mmol, 46.1 mg) was dissolved in 4 mL of hydroiodic acid solution and stirred at 80 °C for 30 min to obtain a transparent metal halide solution. The MIQI solution was then mixed with the metal halide solution and stirred at 80 °C for 60 min to form a homogeneous precursor solution. After heating was stopped, the solution was allowed to cool naturally to room temperature and allowed to crystallize for 12 hours. Filtration yielded wine-red, flaky single crystals (MIQ)PbI3. The obtained crystals were washed three times with hydroiodic acid solution and then dried at 60 °C under a nitrogen atmosphere for 6 h to obtain the target product. Single-crystal X-ray diffraction analysis confirmed that the crystals were one-dimensional inorganic chain-structured hybrid perovskites, such as... Figure 2 As shown.

[0068] Example 2: Preparation of (H2APD)PbI4 layered perovskite material Weigh 0.1 mmol (approximately 18 mg) of 4,4'-hydrazopyridine and dissolve it in 4 mL of hydroiodic acid solution. Stir at room temperature for 15 min to obtain H2APD. 2+ Iodized salt solution; Separately, PbI2 (0.1 mmol, 46.1 mg) was dissolved in 4 mL of HI solution and stirred at 80 °C for 30 min; The two solutions were mixed and kept at 80 °C for 1 h to form a precursor solution. Heating was then stopped, and the solution was allowed to cool slowly to room temperature and stand for 24 hours, during which orange-red flaky crystals (H2APD)PbI4 precipitated. The obtained crystals were filtered and washed with a small amount of HI solution, then dried under vacuum at 60 °C for 6 h to obtain the final product. Single-crystal X-ray diffraction analysis confirmed that the crystals were two-dimensional inorganic layered hybrid perovskites, such as... Figure 3 As shown.

[0069] Example 3: (AeMV)2Pb3I 12 Preparation of low-dimensional perovskite materials Weigh out 1-methyl-1'-aminoethyl-4,4'-bipyridine (AeMV²) + Dissolve 0.05 mmol) in 4 mL of HI solution and stir for 10 min to obtain an organic salt solution; Separately dissolve 0.15 mmol of PbI2 in 4 mL of HI solution and stir at 80 °C for 30 min.

[0070] The two solutions were mixed and reacted at 80 °C for 1 h to obtain the precursor solution; The solution was then slowly cooled to room temperature and allowed to stand for 24 hours, resulting in the precipitation of deep red needle-like crystals (AeMV)2Pb3I. 12 ; After washing the crystalline HI crystals three times, they were dried under nitrogen at 60 °C for 6 h to obtain the target product.

[0071] The crystal was confirmed by single-crystal X-ray diffraction analysis to be a zero-dimensional inorganic cluster-structured hybrid perovskite, such as... Figure 1 As shown.

[0072] Test Example 1: Crystal structure characterization and electronic structure analysis of the (H2APD)PbI4 single crystal material obtained in Example 1. Using the (H2APD)PbI4 single crystal sample prepared in Example 1 as the test object, its crystal structure and electronic structure were characterized by a combination of single crystal X-ray diffraction analysis, theoretical calculation and spectral testing, so as to illustrate the structural characteristics of the material and the electronic structure basis of its infrared gating response.

[0073] (1) Single crystal structure characterization method The (H2APD)PbI4 single crystal sample obtained in Example 1 was selected for single crystal X-ray diffraction test. After collecting diffraction data, the crystal structure and inorganic framework connection mode were analyzed by structural analysis. Based on this, the crystal structure of the material was determined. The crystal structure of (H2APD)PbI4 is shown in Figure 3.

[0074] (2) Methods for determining the dimensions of crystal structure In this application, the structural dimensions of the hybrid perovskite material are determined based on the connection methods in the inorganic metal halide framework: When adjacent octahedrons are isolated from each other and there is no continuous connection between vertices, edges or faces, they can be identified as zero-dimensional discrete cluster structures. When octahedrons are continuously connected in one direction to form a chain-like extended skeleton, it can be identified as a one-dimensional structure. When octahedrons are continuously connected in two directions to form a layered extended skeleton, it can be determined as a two-dimensional structure. like Figure 3 As shown, (H2APD)PbI4 is a two-dimensional structure.

[0075] (3) Characterization results and analysis of single crystal structure Single-crystal X-ray diffraction analysis results show that the (H2APD)PbI4 obtained in Example 1 is an organic-inorganic hybrid lead iodide single-crystal material, in which the inorganic component in its crystal structure is composed of octahedral units formed by the coordination of Pb and I. Based on the connection relationship between adjacent inorganic octahedra, it can be seen that this inorganic framework extends continuously in two directions within the crystal, forming a layered inorganic framework. Therefore, this material can be determined to belong to a two-dimensional layered hybrid perovskite structure.

[0076] (4) Electronic structure calculation method First-principles calculations were performed on the (H2APD)PbI4 crystal obtained in Example 1 using VASP software. The PBE functional and PAW pseudopotential were used, the plane wave cutoff energy was set to 400 eV, and the k-point grid was set to 3×3×3 to analyze its band structure and intermediate energy level distribution characteristics.

[0077] (5) Results of electronic structure analysis The calculation results are as follows Figure 4 As shown. By Figure 4 It is known that the relevant molecular orbitals of the organic components in this material are located below the inorganic conduction band bottom, forming a localized intermediate energy level within the band gap. This intermediate energy level can serve as an electronic transition channel regulated by excited light, providing the electronic structure basis for the material to respond to long-wavelength light under ultraviolet / visible pre-excitation conditions.

[0078] Test Example 2: Infrared Gated Photoelectric Response Test of the (H2APD)PbI4 Single Crystal Material Obtained in Example 1 The (H2APD)PbI4 single crystal sample prepared in Example 1 was used as the test object, and its infrared gating photoelectric response performance under ultraviolet / visible light excitation conditions was tested.

[0079] (1) Device fabrication The (H2APD)PbI4 single crystal obtained in Example 1 was cut into crystal samples of approximately 3 mm × 3 mm × 0.5 mm. Metal electrodes were deposited on opposite sides of the crystal with an electrode thickness of approximately 80 nm to prepare Ag / (H2APD)PbI4 / Ag optoelectronic devices.

[0080] (2) Testing principle The device testing principle is illustrated as follows: Figure 5 As shown. By Figure 5 It is known that under ultraviolet / visible light irradiation, the material is first excited to a responsive state; on this basis, when infrared light is further introduced for irradiation, the material can generate an additional photocurrent signal, thereby realizing gated detection of infrared light. Figure 5 In the diagram, the blue wavy line represents ultraviolet / visible excitation light, and the red wavy line represents the infrared light to be detected. - The direction of electron transport is indicated by the dashed circle, which represents the additional photocurrent response triggered by infrared light.

[0081] (3) Testing equipment Photocurrent testing was performed using a Keithley 4200 semiconductor parameter analyzer, a laser, a xenon lamp UV / Vis light source, and a temperature-controlled probe station.

[0082] (4) Test method First, without additional ultraviolet / visible pre-excitation, the above-mentioned device was irradiated with a near-infrared or short-wave infrared light source, and the current-voltage curve and the response of photocurrent over time were recorded.

[0083] Subsequently, under continuous ultraviolet / visible light irradiation, infrared light irradiation was introduced, and the current-voltage curve and photocurrent response of the device under dual irradiation conditions were tested to investigate the gating effect of ultraviolet / visible light on the infrared response.

[0084] (5) Test results and analysis The current-voltage test results of the sample obtained in Example 1 are as follows: Figure 6 and Figure 7 As shown.

[0085] like Figure 6As shown, the device current changes little under dark conditions and under only light with wavelengths greater than 800 nm; under 520 nm visible light illumination, the device already exhibits a significant photocurrent; when infrared light with wavelengths greater than 800 nm is superimposed on the continuous 520 nm visible light illumination, the device current increases further, indicating that infrared light can induce an additional current response on the basis of visible light pre-excitation.

[0086] like Figure 7 As shown, under dark conditions and with only 2200 nm infrared light irradiation, the device hardly generates any photocurrent; however, under ultraviolet light irradiation with wavelengths less than 420 nm, the device generates a certain photocurrent; when 2200 nm infrared light irradiation is superimposed on the ultraviolet light irradiation, the device current is further enhanced, indicating that the material also has infrared gating response characteristics under ultraviolet pre-excitation conditions.

[0087] The photocurrent test results of the sample obtained in Example 1 are as follows: Figure 8 and Figure 9 As shown.

[0088] like Figure 8 As shown, under no additional excitation conditions, 980 nm infrared light hardly induces a significant photocurrent response; however, under 520 nm or 375 nm excitation conditions, as the power of 980 nm infrared light increases from 0.92 mW to 2.78 mW, the additional photocurrent of the device gradually increases, indicating that the material can produce a stable response to 980 nm infrared light under UV / Vis pre-excitation, and the response intensity increases with the increase of infrared light power.

[0089] like Figure 9 As shown, under no additional excitation conditions, 2200 nm infrared light hardly produces any significant additional current; however, under 520 nm or 375 nm excitation conditions, as the power of 2200 nm infrared light increases from 0.11 mW to 0.48 mW, the additional photocurrent of the device gradually increases, indicating that the material can produce a significant response to 2200 nm infrared light under ultraviolet / visible pre-excitation conditions and exhibits good tunability.

[0090] comprehensive Figures 5 to 9The test results show that the (H2APD)PbI4 material obtained in Example 1 has a weak direct response to infrared light under conditions without UV / Vis pre-excitation; however, under continuous UV / Vis excitation, the material can produce a significantly enhanced photoelectric response to infrared light in the 980 nm to 2200 nm band, and exhibits stable switching behavior and response characteristics that increase with increasing infrared power, proving that the material can achieve infrared light detection gated by UV / Vis light.

[0091] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A charge-transfer state-mediated infrared-gated broadband spectral-response hybrid perovskite material, characterized in that, This includes hybrid metal halide structures, with the general chemical formula A. a M b X c ; Wherein, A is a positively charged organic cation, and the positively charged organic cation contains at least one hetero-nitrogen aromatic ring with an electronic defect; M is a metal cation; X is a halide anion; a, b, and c are positive integers whose values ​​satisfy the overall charge neutrality.

2. The infrared-gated broadband spectral response hybrid perovskite material based on charge transfer state mediation according to claim 1, characterized in that, The hybrid metal halide structure includes organic and inorganic components; The organic component is fixed to the inorganic component through at least one of electrostatic interaction, hydrogen bonding, and van der Waals interaction. The organic component is composed of A, and its lowest unoccupied molecular orbital is located in the energy level range ΔE below the conduction band bottom of the inorganic component, 0.05 eV ≤ ΔE ≤ 1.0 eV; The inorganic component is a metal halide composed of M and X, which has at least one of a zero-dimensional discrete cluster structure, a one-dimensional chain structure, a two-dimensional layered structure, or a three-dimensional continuous framework structure.

3. The infrared-gated broadband spectral response hybrid perovskite material based on charge transfer state mediation according to claim 2, characterized in that, The zero-dimensional discrete cluster structure is a zero-dimensional perovskite-like structure composed of discrete metal halide clusters, wherein the discrete metal halide clusters are completely separated by A and there is no direct metal halide connection between them. Preferably, the one-dimensional chain structure is a one-dimensional chain composed of metal halide coordination polyhedra that share corners, edges, or faces; Preferably, the two-dimensional layered structure is a layered inorganic network composed of metal halide coordination polyhedra with shared corners or edges, wherein A serves as a spacer layer to separate the inorganic components along the c-axis direction, forming a quantum well-type Ruddlesden–Popper structure. Preferably, the three-dimensional continuous framework structure is a three-dimensional perovskite framework composed of angle-shared metal halide octahedrons, wherein part or all of the A sites occupy the A sites and introduce the intermediate zone.

4. The infrared-gated broadband spectral response hybrid perovskite material based on charge transfer state mediation according to claim 1, characterized in that, The heteroacidic aromatic ring of the electronic defect is selected from at least one of pyridinium cations, bipyridinium cations, hydrazine-coupled pyridinium cations, bipyridinium cations, and viologen cations; Preferably, the pyridinium cation is obtained by halogenation, protonation or quaternization of an organic amine or polyamine containing a pyridine ring; Preferably, the bipyridinium cation is obtained by protonation or quaternization of a bipyridine or bispyridine skeleton formed by coupling two pyridine rings; Preferably, the hydrazine-coupled pyridinium cation is obtained by protonation of a hydrazine-bridged bispyridine skeleton; Preferably, the electron defective heteroazo aromatic ring is obtained by conjugating a heteroazo aromatic ring fragment containing a biaryl, diazine, triazine, or naphthidine with a pyridine ring.

5. The infrared-gated broadband spectral response hybrid perovskite material based on charge transfer state mediation according to claim 1, characterized in that, M is a positively charged metal cation; Preferably, the metal element in the metal cation is selected from at least one of Pb, Sn, Ge, Mn, Cu, Bi, and Ag; Preferably, X is selected from Cl — ,Br — I — At least one of them.

6. The method for preparing the infrared-gated broadband spectral-responsive hybrid perovskite material based on charge-transfer state mediation as described in any one of claims 1 to 5, characterized in that, include: According to the general chemical formula A a M b X c The organic amine ligand containing at least one electron defect of a hetero-nitrogen aromatic ring is mixed with a halide acid solution at a stoichiometric ratio of a to obtain a corresponding organic halide salt solution. The metal halide is mixed with the organic halide salt at a stoichiometric ratio of b to obtain a precursor solution. The precursor solution is crystallized to obtain the infrared-gated broadband spectral response hybrid perovskite material based on charge transfer state mediation.

7. The preparation method according to claim 6, characterized in that, The organic amine ligand containing at least one electron defect of a heteroazo aromatic ring is selected from at least one organic amine ligand containing a pyridine, bipyridine, hydrazine-coupled pyridine or viologen skeleton; The crystallization method is selected from one of solution cooling crystallization, solvent evaporation crystallization, antisolvent-induced crystallization, or spin coating-annealing.

8. An infrared-gated broadband response photodetector, characterized in that, It includes a photoelectric material and a first electrode and a second electrode that are disposed opposite to and connected to both sides of the photoelectric material; The optoelectronic material is selected from at least one of the infrared-gated broadband spectral-responsive hybrid perovskite materials based on charge-transfer state mediated as described in any one of claims 1 to 5, or the infrared-gated broadband spectral-responsive hybrid perovskite materials based on charge-transfer state mediated as described in claim 6 or 7.

9. The infrared-gated broadband response photodetector according to claim 8, characterized in that, Under conditions without ultraviolet and / or visible light pre-excitation, the infrared-gated broadband response photodetector does not produce a photoelectric response to infrared light located below the intrinsic bandgap of the photoelectric material; Under the condition of applying ultraviolet and / or visible light pre-excitation, the infrared-gated broadband response photodetector generates a single-photon, near-linear photoelectric response to at least a portion of infrared light in the 300 nm to 9 μm band; Preferably, the infrared-gated broadband response photodetector has a sandwich structure formed by a planar first electrode, a single crystal or thin film of the photoelectric material, and a planar second electrode; Preferably, the first electrode and the second electrode are Ag; Preferably, the photoelectric material is selected from (HEAP)PbI4, (H2APD)PbI4, and (AeMV)2Pb3I. 12 One or a combination thereof, wherein (HEAP)PbI4 and (H2APD)PbI4 are two-dimensional perovskites, and (AeMV)2Pb3I 12 It is a zero-dimensional perovskite.

10. The application of at least one of the charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite materials according to any one of claims 1 to 5, or the charge-transfer state-mediated infrared-gated broadband spectral-responsive hybrid perovskite materials according to the preparation method of claim 6 or 7, in broadband photodetectors, infrared-gated imaging devices, optical communication receivers, solar infrared energy harvesters, or multispectral sensors.

Images