Single crystal perovskite material and preparation method thereof and narrow-band light-responsive detector

Abstract

The present application provides a single-crystalline perovskite material, a preparation method thereof, and a narrow-band light-responsive detector. The single-crystalline perovskite material includes a perovskite single crystal and a metal oxide film layer coated on its surface; the perovskite single crystal includes one or more of the compounds with the general formula MAPbX3. Preparation method of the single-crystalline perovskite material: The perovskite single-crystal precursor solution is allowed to stand under heating conditions, and the perovskite single crystal is obtained by solid-liquid separation; using ozone as the precursor of oxygen and the compound of the metal corresponding to the metal oxide film layer as the metal precursor, atomic layer deposition is carried out on the surface of the perovskite single crystal, thereby introducing an interfacial dipole layer to obtain the single-crystalline perovskite material. The narrow-band light-responsive detector has the above-mentioned single-crystalline perovskite material as its raw material. The single-crystalline perovskite material provided by the present application further narrows the full width at half maximum of the light response, suppresses the background noise, improves the short-wave suppression ratio, effectively improves the stability of the single crystal and enhances the service life of the device.

Description

Technical Field

[0001] The present application relates to the field of materials, and in particular to a single crystal perovskite material and a preparation method thereof and a narrow-band light-responsive detector. Background Art

[0002] In many emerging application areas, such as wearable electronics, the Internet of Things, computer vision, artificial vision, and biosensing, there are high requirements for the detection capabilities of visible and near-infrared light in a narrow wavelength range. For example, the spectral width is usually required to be 100nm or less, and for multi-spectral and hyperspectral detection / imaging, this requirement is even more stringent (down to ≈10nm). Therefore, research on narrow-band light response detection has gradually become a hot topic.

[0003] The so-called narrow-band photoresponse detector utilizes single crystals with narrow-band absorption characteristics or photoactive materials with specific wavelength absorption to achieve selective detection within a narrow wavelength range, while having a high suppression ratio for background noise in the detection environment.

[0004] At present, the methods that can realize narrow-band light response detection mainly include the following: 1. Adding filters to filter out high-energy photons; 2. Using organic molecules as light-absorbing materials and utilizing their narrow characteristic absorption peaks to realize narrow-band light response; 3. With the help of plasma enhancement effect, noble metals are coupled with light-absorbing materials to realize strong absorption of specific light bands; 4. Based on the principle of surface charge collection, the trap state formed by the intrinsic defects on the surface of the material is used to capture the carriers generated by short-wavelength light close to the crystal surface, enhance surface charge recombination and thus suppress the response of the narrow-band detector in the short-wavelength band. The carriers excited by long-wavelength light are far away from the surface and can be better collected by the electrodes under the action of an external electric field. Therefore, the narrow-band characteristics exhibited can realize selective detection in a narrow range.

[0005] Among them, the narrow-band light response of surface charge collection has the best effect, such as simple material and device preparation methods, and high quantum efficiency of the device. And simple chemical methods can be used to achieve precise control of the detection range. However, the defects are uncontrollable, the short-wave response suppression ratio cannot be effectively controlled, and most importantly, the compressed response bandwidth cannot be controlled.

[0006] Therefore, optimizing the narrow-band photoresponse detection range of narrow-band photoresponse detectors and effectively suppressing the short-wave response suppression ratio are important trends in the development of high-performance narrow-band photoresponse detectors. Summary of the invention

[0007] The purpose of the present application is to provide a single crystal perovskite material and a preparation method thereof and a narrow-band light-responsive detector to solve the above-mentioned problems.

[0008] To achieve the above objectives, this application adopts the following technical solutions:

[0009] A single crystal perovskite material, comprising a perovskite single crystal and a metal oxide film layer coated on the surface thereof;

[0010] The perovskite single crystal comprises a general formula of MAPbX 3 One or more of the compounds of, wherein X is one or more of Cl, Br and I.

[0011] Preferably, the material of the metal oxide film layer includes one or more of aluminum oxide, magnesium oxide and hafnium oxide.

[0012] Preferably, the thickness of the metal oxide film layer is 50nm-300nm.

[0013] Preferably, the perovskite single crystal is MAPbBr 3-x Cl x Hybrid perovskites;

[0014] Preferably, the MAPbBr 3-x Cl x The molar ratio of CI to Br in the perovskite is 4:1;

[0015] Preferably, the perovskite single crystal is MAPbI 3-x Br x mixture of

[0016] Preferably, the MAPbI 3-x Br x The molar ratio of Br to I in the perovskite is 15:1.

[0017] Preferably, the size of the perovskite single crystal is:

[0018] The length and width are independently 1mm-20mm, and the height is 1mm-10mm.

[0019] The present application also provides a method for preparing the single crystal perovskite material, comprising:

[0020] The perovskite single crystal precursor solution is allowed to stand under heating conditions to separate the solid from the liquid to obtain the perovskite single crystal;

[0021] Using ozone as an oxygen precursor and a metal compound corresponding to the metal oxide film layer as a metal precursor, atomic layer deposition is performed on the surface of the perovskite single crystal, and then an interface dipole layer is introduced to obtain the single crystal perovskite material.

[0022] Preferably, the perovskite single crystal precursor solution includes PbX 2 and MAX;

[0023] Preferably, the method for preparing the perovskite single crystal precursor solution comprises:

[0024] The PbX 2 , mixing the MAX and solvent, stirring until transparent, and filtering;

[0025] Preferably, the solvent comprises DMF.

[0026] Preferably, the temperature of the heating condition is 80°C-120°C;

[0027] Preferably, the heating conditions include constant temperature or continuous heating;

[0028] Preferably, the standing time is 24h-48h.

[0029] Preferably, the atomic layer deposition comprises:

[0030] The surface of the perovskite single crystal is first activated with ozone, and then the metal oxide film layer is deposited.

[0031] The present application also provides a narrow-band light-responsive detector, the raw material of which includes the single crystal perovskite material.

[0032] Compared with the prior art, the beneficial effects of this application include:

[0033] The single crystal perovskite material provided in this application is due to MAPbCl 3 MAPbBr 3 and MAPbI 3 The absorption edges of these single crystals are located in the purple, green and near-infrared (NIR) ranges, respectively. Therefore, by using these single crystals as the photoactive materials of photodetectors, narrow-band photodetection with adjustable spectral response from blue to red is achieved. The use of metal oxides to form the coating layer mainly plays two roles: (1) introducing carrier confinement energy levels; (2) introducing an interface dipole layer; and (3) effectively improving the stability of the single crystal material and the detector and extending its service life.

[0034] The preparation method of the single crystal perovskite material provided in the present application uses the ALD method to deposit a dense metal oxide film on the surface of the perovskite single crystal. The metal oxide film provides a vacuum microenvironment for the perovskite single crystal, so that the decomposed atoms can be rearranged and reorganized in the environment. Tests have proved that the coating of the metal oxide film greatly improves the photothermal stability of the single crystal device and the photoelectric performance of the device.

[0035] We propose a method to use interface dipoles to control the response bandwidth and short-wavelength suppression ratio of photoresponse detectors. A high dielectric constant metal oxide film is deposited on the surface of single crystal perovskite by atomic layer deposition, and the film width is controlled to modulate the interface dipole, thereby achieving effective control of the short-wavelength response suppression ratio and compressing the response bandwidth.

[0036] The narrow-band light-responsive detector provided in the present application enables precise control of the detection range. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0038] Figure 1 MAPbBr obtained in Example 1 3 Photographs of single crystals;

[0039] Figure 2 MAPbBr 3 SEM photo of single crystal;

[0040] Figure 3 MAPbBr at different magnifications 3 SEM photo of single crystal;

[0041] Figure 4 The single crystal perovskite obtained in Example 1 is coated with Al 2 O 3 SEM photos of thin film materials;

[0042] Figure 5 The single crystal perovskite obtained in Example 1 is coated with Al 2 O 3 SEM photo of another location of the thin film material;

[0043] Figure 6 MAPbBr obtained in Example 1 3 XRD spectrum of single crystal;

[0044] Figure 7 This is the XRD spectrum of the single crystal perovskite material obtained in Example 1;

[0045] Figure 8 MAPbBr obtained in Example 1 3 Single crystal light response characteristic test curve;

[0046] Fig. 9 This is a light response characteristic test curve of the single crystal perovskite material obtained in Example 1;

[0047] Fig.10 MAPbBr obtained in Example 1 3 Photoluminescence spectra of single crystal and monocrystalline perovskite materials;

[0048] Fig.11 This is a photoluminescence test curve of the single crystal perovskite obtained in Example 1 at low temperature and variable power at 15K;

[0049] Fig.12 This is a photoluminescence test curve of the single crystal perovskite-coated alumina material obtained in Example 1 at low temperature and variable power at 15K;

[0050] Fig.13 MAPbI obtained in Example 6 3 Photographs of single crystals;

[0051] Fig.14 MAPbI obtained in Example 6 3 Single crystal light response characteristic test curve;

[0052] Fig.15 MAPbI obtained in Example 6 3 Single crystal coated with Al 2 O 3 Light response characteristic test curve of the material;

[0053] Fig.16 This is a light response characteristic test curve of the CsPbBr3 single crystal perovskite material obtained in Comparative Example 1;

[0054] Fig.17 This is a test curve of the light response characteristics of the single crystal perovskite-coated alumina material obtained in Example 1 under the same test conditions;

[0055] Fig.18 Tested under the same conditions without O 3 Treatment only coated with Al 2 O 3 MAPbBr 3 Single crystal light response characteristic test curve;

[0056] Fig.19 For single crystal MAPbBr 3 and detector normalized response spectra of samples 1-3;

[0057] Fig. 20 Schematic diagram of the structure of a narrow-band photoresponse detector. DETAILED DESCRIPTION

[0058] As used herein:

[0059] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0060] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0061] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0062] In these examples, parts and percentages are by mass unless otherwise indicated.

[0063] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0064] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0065] A single crystal perovskite material, comprising a perovskite single crystal and a metal oxide film layer coated on the surface thereof;

[0066] The perovskite single crystal comprises a general formula of MAPbX 3 One or more of the compounds of, wherein X is one or more of Cl, Br and I.

[0067] Methylammonium lead trihalide perovskite MAPbX 3 (MA=CH 3 NH 3 , X is Cl, Br or I) is an emerging low-cost, solution-processable material with a tunable band gap from the violet to the near-infrared for application in high-performance optoelectronic devices.

[0068] Perovskite single crystals grown in supersaturated solutions inevitably have a large number of surface defects. Its defect density is large, similar to that of polycrystalline thin films, but there are fewer defects inside the single crystal. Therefore, when light of different wavelengths is incident on the surface of the single crystal, light with a shorter wavelength has a smaller penetration depth. Therefore, in thicker single crystals, short wavelengths can only stay on the surface of the single crystal and recombine with point defects on the surface. Therefore, the response spectrum of the detector is smaller at short wavelengths. On the contrary, long-wave light with energy lower than the band gap excitation energy has a larger penetration depth due to its smaller absorption coefficient, so it can be incident into the interior of the crystal. The generated photogenerated charge is not easily affected by surface recombination, so the detector response is higher in the long-wave region. It is precisely because of the surface recombination caused by such defect differences that the single crystal has a narrowband characteristic of characteristic absorption.

[0069] In an optional embodiment, the material of the metal oxide film layer includes one or more of aluminum oxide, magnesium oxide and hafnium oxide.

[0070] In an optional embodiment, the thickness of the metal oxide film layer is 50nm-300nm.

[0071] Optionally, the thickness of the oxide film layer may be 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm or any value between 50 nm and 300 nm.

[0072] In an optional embodiment, the perovskite single crystal is MAPbBr 3-x Cl x Hybrid perovskites;

[0073] In an alternative embodiment, the MAPbBr 3-x Cl x The molar ratio of CI to Br in the perovskite is 4:1;

[0074] In an optional embodiment, the perovskite single crystal is MAPbI 3-x Br x mixture of

[0075] In an optional embodiment, the MAPbI 3-x Br x The molar ratio of Br to I in the perovskite is 15:1.

[0076] By controlling the single crystal composition, not only the response range of the narrow-band light-responsive detector is broadened, but also the change of the X-position element extends the narrow-band single crystal perovskite to the field of all-inorganic and double perovskite, further enriching the material composition and structural system of the single crystal perovskite detector.

[0077] In an optional embodiment, the size of the perovskite single crystal is:

[0078] The length and width are independently 1mm-20mm, and the height is 1mm-10mm.

[0079] Optionally, the length and width of the perovskite single crystal can independently be 1mm, 5mm, 10mm, 15mm, 20mm or any value between 1mm-20mm, and the height can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or any value between 1mm-10mm.

[0080] The present application also provides a method for preparing the single crystal perovskite material, comprising:

[0081] The perovskite single crystal precursor solution is allowed to stand under heating conditions to separate the solid from the liquid to obtain the perovskite single crystal;

[0082] Using ozone as an oxygen precursor and a metal compound corresponding to the metal oxide film layer as a metal precursor, atomic layer deposition is performed on the surface of the perovskite single crystal to obtain the single crystal perovskite material.

[0083] In an optional embodiment, the perovskite single crystal precursor solution includes PbX 2 and MAX;

[0084] In an optional embodiment, the method for preparing the perovskite single crystal precursor solution comprises:

[0085] The PbX 2 , mixing the MAX and solvent, stirring until transparent, and filtering;

[0086] In an alternative embodiment, the solvent comprises DMF.

[0087] In an optional embodiment, the temperature of the heating condition is 80°C-120°C;

[0088] In an optional embodiment, the heating conditions include constant temperature or continuous heating;

[0089] In an optional embodiment, the standing time is 24h-48h.

[0090] Optionally, the temperature of the heating condition can be 80°C, 90°C, 100°C, 110°C, 120°C or any value between 80°C and 120°C; the standing time can be 24h, 30h, 36h, 42h, 48h or any value between 24h and 48h.

[0091] In an optional embodiment, the atomic deposition comprises:

[0092] The surface of the perovskite single crystal is first activated with ozone, and then the metal oxide film layer is deposited.

[0093] The present application also provides a narrow-band light-responsive detector, the raw material of which includes the single crystal perovskite material.

[0094] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0095] Example 1

[0096] a.MAPbBr 3 Single crystal growth

[0097] (1) Preparation of precursor solution: Weigh 1.101 of PbBr 2 Powder and 0.3357 MABr powder were placed in a 10 mL beaker, 5 mL of DMF solution was measured with a pipette and added to the beaker to prepare a precursor solution with a molar concentration of 0.6 mol / L, placed in a magnetic rotor and sealed with tin foil, and stirred with a stirrer at room temperature for 1 h until the precursor solution becomes transparent. The obtained transparent precursor solution was filtered with a 0.22 μm syringe filter and placed in a culture dish.

[0098] (2) Single crystal growth: The filtered transparent precursor solution was placed in a constant temperature drying oven at 80°C for 24 hours. Several 0.4-1.5 cm 2 Size of single crystal.

[0099] (3) Storage of single crystals: When the temperature rises to 80°C, the single crystal stops growing. The single crystal is taken out from the solution and the residual solution is absorbed with filter paper. The single crystal is placed in a constant temperature drying oven at 60°C for drying. After being taken out, it is sealed and stored in a moisture-proof cabinet.

[0100] b.ALD alumina coating

[0101] At 50°C, 1×10 -2 Under vacuum conditions of 1.5 pa, with O 3 As oxygen precursor, trimethylaluminum (TMA) was used as aluminum precursor. The deposition rate was about The specific deposition process is as follows:

[0102] First, a 40% concentration of O 3 The flow rate was 40 sccm and the pulse was 0.02 sec. 3 While activating the surface of the perovskite single crystal, Al 2 O 3 The smaller Al-OH bonds and Al-Al bonds are formed through O 3 Replace the traditional H 2 O. Because Al-OH bond and Al-Al bond are Al 2 O 3 An important source of surface defects, so O 3 As a precursor, Al 2 O 3 It has better film quality. After waiting for ten seconds for the effect to be complete, a 0.02 second TMA pulse is applied, and the following chemical reaction occurs: 2Al(CH 3 )+O 3 =Al 2 O 3 +3C 2 H 6 . Extra C 2 H 6 Will be eliminated. Wait another ten seconds for the reaction to complete, and then start the next cycle. After the cycle is completed, 100nm of Al can be formed on the surface of the single crystal. 2 O 3 of film deposition.

[0103] Figure 1 MAPbBr obtained in Example 1 3 Photo of a single crystal, dimensions are 12mm long × 12mm wide × 2mm high.

[0104] Figure 2 and Figure 3 MAPbBr at different magnifications 3 SEM image of single crystal.

[0105] Figure 4 and Figure 5 The single crystal perovskite obtained in Example 1 is coated with Al 2 O 3 SEM photos of thin film materials at different locations, showing Al on the surface of the single crystal 2 O 3 Membrane layer.

[0106] Figure 6 MAPbBr obtained in Example 1 3 XRD spectrum of single crystal, Figure 7 The single crystal perovskite obtained in Example 1 is coated with Al 2 O 3 XRD spectra of thin film materials.

[0107] MAPbB 3 Single crystal and MAPbBr 3 Single crystal coated with Al 2 O 3 The XRD spectra of the thin film material show four MAPbBr at the same positions (001), (002), (003) and (004). 3 The single crystal characteristic peaks and the absence of other impurity peaks indicate that the single crystal synthesis quality is good and exhibits single crystal characteristics.

[0108] The MAPbBr obtained in Example 1 3 Single crystal and MAPbBr 3 Single crystal coated with Al 2 O 3 The light response characteristics of the film materials were tested separately, and the results are as follows Figure 8 and Fig. 9 shown.

[0109] Compared with MAPbBr 3 Photoresponse curve of single crystal, coated with Al 2 O 3 The photoresponse curve of the single crystal after filming is suppressed on the high energy side, showing a similar 3 Different narrowband properties of single crystals.

[0110] Fig.10 MAPbBr obtained in Example 1 3 Single crystal and MAPbBr 3 Single crystal coated with Al 2 O 3 Photoluminescence spectra (PL) of thin film materials.

[0111] Compared with MAPbBr 3 PL peak position of single crystal, coated with Al 2 O 3The peak position of the single crystal after film formation is slightly red-shifted and the intensity increases.

[0112] Fig.11 and Fig.12 (From top to bottom in the two figures, the corresponding power decreases successively) is low temperature variable power photoluminescence. Two peaks appear at 559nm and 545nm before and after coating. The low energy peak is the impurity peak. After comparison, it is found that the luminescence peak of impurities is enhanced after coating with aluminum oxide. It proves that more defect energy levels are indeed introduced in the process of ALD growth of aluminum oxide.

[0113] Example 2

[0114] a.MAPbBr 3 Single crystal growth

[0115] (1) Preparation of precursor solution: Weigh 0.734 of PbBr 2 Powder and 0.224 MABr powder were placed in a 10 mL beaker, 2 mL of DMF solution was measured with a pipette and added to the beaker to prepare a precursor solution with a substance concentration of 1 mol / L, placed in a magnetic rotor and sealed with tin foil, and stirred with a stirrer at room temperature for 1 h until the precursor solution becomes transparent. The obtained transparent precursor solution was filtered with a 0.22 μm syringe filter and placed in a culture dish.

[0116] (2) Growth of single crystals: The filtered transparent precursor solution was placed in a constant temperature drying oven at 90°C for 24 hours. Several 0.6 cm thick particles appeared at the bottom of the beaker. 2 Size of single crystal.

[0117] (3) Storage of single crystals: When the temperature rises to 90°C, the single crystal stops growing. The single crystal is taken out from the solution and the residual solution is absorbed with filter paper. The single crystal is placed in a constant temperature drying oven at 60°C for drying. After being taken out, it is sealed and stored in a moisture-proof cabinet.

[0118] b.ALD alumina coating

[0119] At 100°C and 1×10 -2 Under vacuum conditions of 1.5 pa, with O 3 As oxygen precursor, trimethylaluminum (TMA) was used as aluminum precursor. The deposition rate was about The specific deposition process is as follows:

[0120] First, a 40% concentration of O 3 The flow rate was 40 sccm and the pulse was 0.02 sec. 3 While activating the surface of the perovskite single crystal, Al 2 O 3 The smaller Al-OH bonds and Al-Al bonds are formed through O3 Replace the traditional H 2 O. Because Al-OH bond and Al-Al bond are Al 2 O 3 An important source of surface defects, so O 3 As a precursor, Al 2 O 3 It has better film quality. After waiting for ten seconds for the effect to be complete, a 0.02 second TMA pulse is applied, and the following chemical reaction occurs: 2Al(CH 3 )+O 3 =Al 2 O 3 +3C 2 H 6 . Extra C 2 H 6 Will be eliminated. Wait another ten seconds for the reaction to complete, and then start the next cycle. After the cycle is completed, 200nm of Al can be formed on the surface of the single crystal. 2 O 3 of film deposition.

[0121] Example 3

[0122] a.MAPbBr 3 Single crystal growth

[0123] (1) Preparation of precursor solution: Weigh 0.734 of PbBr 2 Powder and 0.224 MABr powder were placed in a 10 mL beaker, 2 mL of DMF solution was measured with a pipette and added to the beaker to prepare a precursor solution with a substance concentration of 1 mol / L, placed in a magnetic rotor and sealed with tin foil, and stirred with a stirrer at room temperature for 1 h until the precursor solution becomes transparent. The obtained transparent precursor solution was filtered with a 0.22 μm syringe filter and placed in a 4 ml sample bottle.

[0124] (2) Single crystal growth: Place the filtered transparent precursor solution on a heating table and heat it at 110°C for 4 h and 24 h. Several ~4 cm thick particles will appear at the bottom of the sample bottle. 2 Size of single crystal.

[0125] (3) Storage of single crystals: After the single crystal stops growing, take the single crystal out of the solution and use filter paper to absorb the remaining solution. Place it in a constant temperature drying oven to dry at 60°C. After taking it out, place it in a moisture-proof cabinet and seal it for storage.

[0126] b.ALD alumina coating

[0127] At 150°C and 1×10 -2 Under vacuum conditions of 1.5 pa, with O3 As oxygen precursor, trimethylaluminum (TMA) was used as aluminum precursor. The deposition rate was about The specific deposition process is as follows:

[0128] First, a 40% concentration of O 3 The flow rate was 40 sccm and the pulse was 0.02 sec. 3 While activating the surface of the perovskite single crystal, Al 2 O 3 The smaller Al-OH bonds and Al-Al bonds are formed through O 3 Replace the traditional H 2 O. Because Al-OH bond and Al-Al bond are Al 2 O 3 An important source of surface defects, so O 3 As a precursor, Al 2 O 3 It has better film quality. After waiting for ten seconds for the effect to be complete, a 0.02 second TMA pulse is applied, and the following chemical reaction occurs: 2Al(CH 3 )+O 3 =Al 2 O 3 +3C 2 H 6 . Extra C 2 H 6 Will be eliminated. Wait another ten seconds for the reaction to complete, and then start the next cycle. After the cycle is completed, 250nm of Al can be completed on the surface of the single crystal. 2 O 3 of film deposition.

[0129] Example 4

[0130] a.MAPbBr 3 Single crystal growth

[0131] (1) Preparation of precursor solution: Weigh 0.734 of PbBr 2 Powder and 0.224 MABr powder were placed in a 10 mL beaker, 2 mL of DMF solution was measured with a pipette and added to the beaker to prepare a precursor solution with a substance concentration of 1 mol / L, placed in a magnetic rotor and sealed with tin foil, and stirred with a stirrer at room temperature for 1 h until the precursor solution becomes transparent. The obtained transparent precursor solution was filtered with a 0.22 μm syringe filter and placed in a culture dish.

[0132] (2) Growth of single crystals: The filtered transparent precursor solution was placed in a constant temperature drying oven at 90°C for 24 hours. Several 0.6 cm thick particles appeared at the bottom of the beaker.2 Size of single crystal.

[0133] (3) Storage of single crystals: When the temperature rises to 90°C, the single crystal stops growing. The single crystal is taken out from the solution and the residual solution is absorbed with filter paper. The single crystal is placed in a constant temperature drying oven at 60°C for drying. After being taken out, it is sealed and stored in a moisture-proof cabinet.

[0134] b. ALD hafnium oxide coating

[0135] At 100°C and 1×10 -2 Under vacuum conditions of 1.5 pa, with O 3 As the oxygen precursor, tetra(methylethylamine)hafnium (TEMAHf) was used as the hafnium source precursor. The deposition rate was about The pulse time of TEMAHf precursor is 1.6s, the carrier gas volume is 120sccm, and the high-purity nitrogen purge time is 5s; 3 As a precursor, an ozone generator with 90% power and a carrier gas volume of 100 sccm was used. 3 The pulse duration is 0.8s, and the high-purity nitrogen purge time is 6s; H 2 The O precursor carrier gas volume is 150sccm, the pulse duration is 0.2s, and the high-purity nitrogen purge time is 5s. After the cycle is completed, 200nm of Al can be formed on the single crystal surface. 2 O 3 of film deposition.

[0136] Example 5

[0137] a.MAPbBr 3 Single crystal growth

[0138] (1) Preparation of precursor solution: Weigh 0.734 of PbBr 2 Powder and 0.224 MABr powder were placed in a 10 mL beaker, 2 mL of DMF solution was measured with a pipette and added to the beaker to prepare a precursor solution with a substance concentration of 1 mol / L, placed in a magnetic rotor and sealed with tin foil, and stirred with a stirrer at room temperature for 1 h until the precursor solution becomes transparent. The obtained transparent precursor solution was filtered with a 0.22 μm syringe filter and placed in a culture dish.

[0139] (2) Growth of single crystals: The filtered transparent precursor solution was placed in a constant temperature drying oven at 90°C for 24 hours. Several 0.6 cm thick particles appeared at the bottom of the beaker. 2 Size of single crystal.

[0140] (3) Storage of single crystals: When the temperature rises to 90°C, the single crystal stops growing. The single crystal is taken out from the solution and the residual solution is absorbed with filter paper. The single crystal is placed in a constant temperature drying oven at 60°C for drying. After being taken out, it is sealed and stored in a moisture-proof cabinet.

[0141] b.ALD alumina coating

[0142] At 50°C, 1×10 -2 Under vacuum conditions of 1.5 pa, with O 3 As oxygen precursor, trimethylaluminum (TMA) was used as aluminum precursor. The deposition rate was about The specific deposition process is as follows:

[0143] First, a 40% concentration of O 3 The flow rate was 40 sccm and the pulse was 0.1 sec. 3 While activating the surface of the perovskite single crystal, Al 2 O 3 The smaller Al-OH bonds and Al-Al bonds are formed through O 3 Replace the traditional H 2 O. Because Al-OH bond and Al-Al bond are Al 2 O 3 An important source of surface defects, so O 3 As a precursor, Al 2 O 3 It has better film quality. After waiting for ten seconds for the effect to be complete, a 0.02 second TMA pulse is applied, and the following chemical reaction occurs: 2Al(CH 3 )+O 3 =Al 2 O 3 +3C 2 H 6 . Extra C 2 H 6 Will be eliminated. Wait another ten seconds for the reaction to complete, and then start the next cycle. After the cycle is completed, 100nm of Al can be formed on the surface of the single crystal. 2 O 3 of film deposition.

[0144] Example 6

[0145] a.MAPbI 3 Single crystal growth

[0146] (1) Preparation of precursor solution: Weigh 1.383% PbI 2The powder and 0.477 of MAI powder were placed in a 10 mL beaker. 5 mL of DMF solution was measured with a pipette and added to the beaker to prepare a precursor solution with a molar concentration of 0.6 mol / L. After being placed in a magnetic rotor, it was sealed with tin foil and stirred with a stirrer at room temperature for 1 hour until the precursor solution became transparent. The obtained transparent precursor solution was filtered with a 0.22 μm syringe filter and placed in a culture dish. It was directly placed on a hot plate at 120°C for heating. Heating for 48 hours can obtain a 1-3 mm single crystal material.

[0147] Fig.13 MAPbI obtained in Example 6 3 Photo of a single crystal.

[0148] (2) Storage of single crystals: When the temperature rises to 90°C, the single crystal stops growing. The single crystal is taken out from the solution and the residual solution is absorbed with filter paper. The single crystal is placed in a constant temperature drying oven at 60°C for drying. After being taken out, it is sealed and stored in a moisture-proof cabinet.

[0149] b.ALD alumina coating

[0150] At 50°C, 1×10 -2 Under vacuum conditions of 1.5 pa, with O 3 As oxygen precursor, trimethylaluminum (TMA) was used as aluminum precursor. The deposition rate was about The specific deposition process is as follows:

[0151] First, a 40% concentration of O 3 The flow rate was 40 sccm and the pulse was 0.1 sec. 3 While activating the surface of the perovskite single crystal, Al 2 O 3 The smaller Al-OH bonds and Al-Al bonds are formed through O 3 Replace the traditional H 2 O. Because Al-OH bond and Al-Al bond are Al 2 O 3 An important source of surface defects, so O 3 As a precursor, Al 2 O 3 It has better film quality. After waiting for ten seconds for the effect to be complete, a 0.02 second TMA pulse is applied, and the following chemical reaction occurs: 2Al(CH 3 )+O 3 =Al 2 O 3 +3C 2 H 6 . Extra C 2 H 6Will be eliminated. Wait another ten seconds for the reaction to complete, and then start the next cycle. After the cycle is completed, 50nm of Al can be formed on the surface of the single crystal. 2 O 3 of film deposition.

[0152] The MAPbI obtained in Example 6 3 The light response characteristics of single crystal and single crystal perovskite materials were tested respectively, and the results are as follows Fig.14 and Fig.15 shown.

[0153] Example 7

[0154] The equimolar ratio of CH 3 NH 3 I, PbI 2 (98%) (molar ratio 1:1) and an equal molar ratio of CH 3 NH 3 Br,PbBr 2 (99%) (molar ratio 1:1) was dissolved in a mixed solvent of DMF and GBL at a molar ratio of 1:15 at 70°C (the volume ratio of the mixed solvent of DMF and GBL was equal to that of PbBr 2 :PbI 2 After the precursor is dissolved and becomes transparent, it is filtered with a 0.22 μm syringe filter. The clarified precursor solution is placed in a culture dish and heated on a hot plate at 100°C. After about 48 hours, CH 3 NH 3 PbI 3-x Br x Single crystal.

[0155] Example 8

[0156] The equimolar ratio of CH 3 NH 3 Br,PbBr 2 (99%) (molar ratio 1:1) and an equal molar ratio of CH 3 NH 3 Cl, PbCl 2 (99.99%) (molar ratio 1:1) was dissolved in a DMSO / DMF mixed solvent at a molar ratio of 4:1 at room temperature (the volume ratio of the DMSO / DMF mixed solvent was equal to that of PbCl 2 After the precursor is dissolved and becomes transparent, it is filtered with a 0.22 μm syringe filter. The clarified precursor solution is placed in a culture dish and heated on a hot plate at 80°C. After about 48 hours, CH 3 NH 3 PbB3-x Cl x Single crystal.

[0157] Comparative Example 1

[0158] The difference from Example 1 is that CsPbBr 3 Single crystal replacement of MAPbBr 3 .

[0159] The obtained materials were tested and the results were as follows Fig.16 shown.

[0160] The single crystal perovskite material obtained in Example 1 was tested under the same conditions, and the results are as follows: Fig.17 shown.

[0161] Depend on Fig.16 and Fig.17 By comparison, MAPbBr 3 Compared with CsPbBr 3 Compared with , it has higher responsiveness and narrower response width.

[0162] Cb 3 The single crystal preparation method is as follows:

[0163] First, prepare 1.1 mol / L CsBr in HBr solution and 1.9 mol / L PbBr 2 The HBr solution was then titrated at a ratio of 1.01:1 to obtain high-purity CsPbBr 3 Powder. CsPbBr 3 The powder was placed in a quartz ampoule coated with carbon film and then evacuated to 10 -4 Pa, and then melted and sealed, and finally placed in a heat treatment furnace and heated to 580 ° C for 2 hours, and finally cooled to room temperature after 12 hours, and CsPbBr was obtained for single crystal growth. 3 Powder.

[0164] The ampoule is placed in the quartz tube of the horizontal moving zone furnace, and the heater is moved so that its initial position is at the tip of the ampoule. The heater of the horizontal moving zone furnace is heated to 640-650℃, and the mechanical moving device is controlled to move the heater in the horizontal moving zone furnace at a certain speed, so that the heater moves from the tip of the ampoule to the tail end. During this period, the temperature of the heater remains unchanged. The movement of the heater drives the movement of the solid-liquid interface, and the CsPbBr 3 Crystal growth.

[0165] Comparative Example 2

[0166] Different from Example 1, ozone is not used as the oxygen precursor.

[0167] Tested under the same conditions without O 3 Treatment only coated with Al 2 O 3 MAPbBr 3 The light response characteristic curve of the single crystal is shown in the following figure. Fig.18 shown.

[0168] Depend on Fig.18 and Fig. 9 By comparison, Fig. 9 Through O 3 The light response of the treated single crystal showed obvious suppression effect at high energy. Fig.18 Not passed through O 3 The photoresponse of the treated single crystals did not show a significant inhibitory effect, which can be explained by the fact that O 3 The crystal surface can be corroded to introduce more defects on the crystal surface or near the surface, thereby enhancing surface recombination and reducing the enhanced suppression ratio of high-energy photometric response.

[0169] It should be noted that the MAPbX used in this application 3 Single crystal and MAPbX 3 There are essential differences between microcrystals, as follows:

[0170] a. Different sizes

[0171] The size of single crystals is in the order of centimeters while the size of crystallites is in the order of micrometers.

[0172] b. Different preparation methods

[0173] Single crystal preparation method:

[0174] The inversion temperature crystallization (ITC) method is based on an unusual reverse solubility system, that is, at high temperatures, the solubility in a specific organic solvent or solvent gradually decreases. Therefore, when heated at high temperatures, once the solution reaches the supersaturated stage, nucleation and crystallization will occur.

[0175] Please refer to the embodiments of this application for details.

[0176] Microcrystal preparation method:

[0177] The perovskite microcrystals were synthesized by a one-step solution deposition method. 3 NH 3 Br and 0.367gPbBr 2 Mix in dimethylformamide solvent to form a precursor solution. Then stir at 60 ° C overnight. Use a pipette to measure 5 μL of the perovskite solution, drop it onto a 2 cm × 6 cm glass substrate, and spread it evenly. Finally, the sample is annealed at 90 ° C for about 10 minutes to generate microcrystals.

[0178] c. Different defect locations

[0179] Single crystals have no grain boundaries, and their defects are mostly concentrated on the crystal surface, similar to polycrystalline films, with fewer defects inside the single crystal.

[0180] It should also be noted that there is an essential difference between using ozone and oxygen as precursors: ozone can corrode the surface of perovskite, break the surface and introduce defects. The introduction and change of surface defects enhances surface recombination and can enhance the narrow spectrum suppression ratio; oxygen does not have this function.

[0181] In order to illustrate the effect of the thickness of the metal oxide film coated on the surface of the perovskite single crystal on the performance of the obtained detector, the method provided in Example 1 was used as a basis to prepare MAPbBr coated with 12nm, 25nm, and 50nm of aluminum oxide, respectively. 3 Materials (samples 1, 2, and 3), and then the normalized response spectra of the detectors corresponding to the single crystal and samples 1, 2, and 3 are obtained as follows Fig.19 shown.

[0182] Depend on Fig.19 It can be seen that as the thickness of the coated aluminum oxide increases, the introduced interface dipole states increase, causing the space charge region to grow, so the short-wave (high-energy photon) cutoff edge gradually red-shifts.

[0183] The present application also provides a narrow-band light response detector, the structural diagram of which is shown in FIG. Fig. 20 shown.

[0184] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0185] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A narrow-band photoresponse detector, It is characterized in that The raw materials include single crystal perovskite material, which includes a single crystal perovskite and a metal oxide film layer coated on the surface thereof; The perovskite single crystal comprises a general formula of MAPbX 3 One or more compounds of, wherein X is one or more of Cl, Br and I; The material of the metal oxide film layer includes one or more of aluminum oxide and hafnium oxide; The thickness of the metal oxide film layer is 50nm-300nm.

2. The narrow-band photoresponse detector according to claim 1, It is characterized in that The perovskite single crystal is MAPbBr 3- x Cl x of hybrid perovskites.

3. The narrow-band photoresponse detector according to claim 2, It is characterized in that The MAPbBr 3-x Cl x The molar ratio of CI to Br in the perovskite is 4:

1.

4. The narrow-band photoresponse detector according to claim 1, It is characterized in that The perovskite single crystal is MAPbI 3- x Br x mixture.

5. The narrow-band photoresponsive detector according to claim 4, It is characterized in that The MAPbI 3-x Br x The molar ratio of Br to I in the perovskite is 15:

1.

6. The narrow-band photoresponsive detector according to any one of claims 1 to 5, It is characterized in that The size of the perovskite single crystal is: The length and width are independently 1mm-20mm, and the height is 1mm-10mm.

7. The narrow-band photoresponsive detector according to claim 1, It is characterized in that The preparation method of the single crystal perovskite material comprises: The perovskite single crystal precursor solution is allowed to stand under heating conditions to separate the solid from the liquid to obtain the perovskite single crystal; Using ozone as an oxygen precursor and a metal compound corresponding to the metal oxide film layer as a metal precursor, performing atomic layer deposition on the surface of the perovskite single crystal, and then introducing an interface dipole layer to obtain the single crystal perovskite material; The perovskite single crystal precursor solution includes PbX 2 and MAX; The method for preparing the perovskite single crystal precursor solution comprises: The PbX 2 , mixing the MAX and solvent, stirring until transparent, and filtering; The solvent included DMF.

8. The narrow-band photoresponsive detector according to claim 7, It is characterized in that The temperature of the heating condition is 80°C-120°C.

9. The narrow-band photoresponsive detector according to claim 7, It is characterized in that The heating conditions include constant temperature or continuous heating.

10. The narrow-band photoresponsive detector according to claim 7, It is characterized in that The standing time is 24h-48h.

11. The narrow-band photoresponsive detector according to any one of claims 7 to 10, It is characterized in that The atomic layer deposition comprises: The surface of the perovskite single crystal is first activated with ozone, and then the metal oxide film layer is deposited.

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