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CN-121985714-A - Air-stable perovskite wafer detector and preparation method thereof

CN121985714ACN 121985714 ACN121985714 ACN 121985714ACN-121985714-A

Abstract

The invention discloses an air-stable perovskite wafer detector and a preparation method thereof, and belongs to the technical field of solar cells. According to the method, the crystallization of perovskite and the in-situ polymerization of polypyrrole at the grain boundary are synchronously completed in an integrated hot-pressing process, and the compact perovskite wafer with a stable and conductive controllable grain boundary network is prepared by a one-step method. The preparation method comprises the steps of perovskite powder preparation, perovskite ammonium acetate adduct preparation, pyrrole monomer solution preparation, perovskite/pyrrole monomer composite powder preparation, mixed powder preparation, wafer hot press molding and device preparation. The obtained detector has excellent stability in an air environment, the 30-minute continuous working current offset is only 0.1%, and the sensitivity is high, so that the detector can be widely applied to the field of multiband photoelectric detection.

Inventors

  • LI YUNLONG
  • CHEN HUIWEN
  • ZHAO BO

Assignees

  • 中国科学院深圳先进技术研究院

Dates

Publication Date
20260505
Application Date
20251222

Claims (10)

  1. 1. The preparation method of the air-stable perovskite wafer detector is characterized by comprising the following steps of: step 1) perovskite powder preparation, namely dissolving precursor salt of all-inorganic perovskite in a good solvent, adding an anti-solvent to precipitate the precursor salt, and carrying out solid-liquid separation, washing and drying to obtain all-inorganic perovskite powder; Step 2) preparing a perovskite ammonium acetate adduct, namely mixing perovskite powder obtained in the step 1) with liquid ammonium carboxylate, washing with a low-polarity solvent and drying to obtain the adduct of perovskite and ammonium carboxylate; step 3) preparing pyrrole monomer solution, namely dissolving pyrrole monomer into an organic solvent which has low polarity, low boiling point and is stable to perovskite to obtain pyrrole monomer solution; Grinding and mixing the perovskite powder obtained in the step 1) and the pyrrole monomer solution obtained in the step 3), and carrying out vacuum drying at a low temperature to obtain ultra-dry perovskite/pyrrole monomer composite powder; Step 5) preparing mixed powder, namely mixing the perovskite/pyrrole monomer composite powder obtained in step 4), the perovskite ammonium acetate adduct obtained in step 2) and the low-boiling-point aprotic or inert proton solvent in proportion, and grinding uniformly to obtain mixed powder; Filling the mixed powder obtained in the step 5) in a hot-pressing die, heating to a set temperature, applying pressure, maintaining the pressure for a certain time, synchronously completing thermal decomposition and volatilization of carboxylate, promoting growth of perovskite crystal grains, in-situ polymerization of pyrrole monomers and removal of solvent, and finally obtaining the polypyrrole modified crystal boundary all-inorganic perovskite wafer; and 7) preparing the device, namely preparing a patterned electrode on the surface of the wafer obtained in the step 6) to obtain the perovskite wafer detector device.
  2. 2. The method for preparing an air stable perovskite wafer detector according to claim 1, wherein in the step 1), the all-inorganic perovskite is CsPbBr 3 or Cs 2 AgBiBr 6 , and the precursor salt of the all-inorganic perovskite comprises CsBr corresponding to CsPbBr 3 and PbBr 2 or CsBr corresponding to Cs 2 AgBiBr 6 , agBr and BiBr 3 ; The good solvent is dimethyl sulfoxide (DMSO), N-Dimethylformamide (DMF), N-dimethyl propenyl urea (DMPU) or N, N-dimethylacetamide (DMAc), preferably DMSO or DMPU; The concentration of a precursor solution formed by dissolving the precursor salt of the perovskite in a good solvent is 0.3-0.6 mol/L, preferably 0.4-0.5 mol/L; The anti-solvent is an alcohol, nitrile or ester solvent, preferably an alcohol solvent, and the volume of the added anti-solvent is 1-20 times of that of the good solvent; The solid-liquid separation mode is centrifugation or filtration, the centrifugal speed is 4000-10000 rpm, and the time is 5-10 minutes; The solvent adopted in the washing is n-hexane, toluene, alcohols and nitriles; And the drying is carried out by adopting vacuum drying, and the drying is carried out for 2-12 hours under the condition that the vacuum drying temperature is 50-80 ℃ and the vacuum degree is lower than-0.08 MPa.
  3. 3. The method of manufacturing an air stable perovskite wafer probe according to claim 1, wherein in step 2), the liquid ammonium carboxylate salt is methylammonium formate (MAFc), ethylammonium formate (EAFc), formamidine formate (FAFc), methylammonium acetate (MAAc), ethylammonium acetate (EAAc) or formamidine acetate (FAAc), preferably methylammonium acetate (MAAc) or methylammonium formate (MAFc); The mixing mode is mechanical grinding or high-speed vortex stirring, and the mixing concentration of the perovskite powder and the liquid ammonium salt is 0.1-3 g/mL, preferably 1-2 g/mL; the solvent adopted in the washing is an organic solvent with polarity lower than that of methanol, and comprises acetone, dichloromethane, n-hexane, toluene, chlorobenzene and ethyl acetate; and the drying is carried out by adopting vacuum drying, and the drying is carried out for 10-30 minutes at the vacuum drying temperature of 40-60 ℃.
  4. 4. The method for preparing an air-stable perovskite wafer detector according to claim 1, wherein in the step 3), the concentration of the organic solvent or toluene, n-hexane, chlorobenzene, acetonitrile or isopropanol, and the concentration of the pyrrole monomer solution ranges from 0.1 to 1.0mol/L.
  5. 5. The method for preparing an air stable perovskite wafer probe according to claim 1, wherein in the step 4), the grinding and mixing are performed by a mechanical grinding mode, the mechanical grinding is performed in an agate mortar or a ball mill, and the liquid monomer solution is fully and uniformly contacted with the solid powder by a shearing force to form a wet mixed material; the mass and volume ratio of the perovskite powder to the prepared pyrrole monomer is 0.5-4 g/mL; the condition of low-temperature vacuum drying is that the control temperature is less than 60 ℃, and the vacuum degree is lower than-0.08 MPa.
  6. 6. The method for preparing an air-stable perovskite wafer detector according to claim 1, wherein in the step 5), the oxidation-reduction potential of the weak oxidant is between +0.5 and +1.V, and is at least one selected from trivalent ferric salt and divalent molybdenum salt; The low-boiling point solvent is acetonitrile, acetone, methyl acetate or 2-methyltetrahydrofuran; The grinding is performed in an agate mortar or ball mill; the mass ratio of the adduct to the composite powder is (1-20) 1000, preferably (10-15) 1000; the mass ratio of the weak oxidant to the composite powder is (1-300): 1000, preferably (5-20): 1000.
  7. 7. The method of claim 1, wherein in step 6), the wafer preparation process comprises the following three steps: (1) Filling the mixed powder obtained in the step 5) into a hot-pressing mold, and then heating the mold until a material system in the mold reaches and stabilizes at a preset process temperature, wherein the process temperature is 80-300 ℃, preferably 120-200 ℃; (2) After the temperature is stable, high pressure is applied and the pressure is maintained for a set time, wherein the pressure range is 10-100 MPa, and preferably 20-50 MPa. (3) And after the pressure maintaining set condition is reached, removing the heating equipment, and naturally cooling the wafer to form the composite wafer modified by taking perovskite crystal grains as a matrix and taking a polypyrrole continuous network as a crystal boundary.
  8. 8. The method of claim 1, wherein in step 7), the patterned electrode is prepared by thermal evaporation, sputtering, photolithography, or screen printing, and a conductive electrode is prepared on the wafer surface to form an effective ohmic contact, and the conductive electrode comprises gold, silver, and carbon.
  9. 9. The method of claim 1, wherein in step 5), the function of the low boiling aprotic or inert protic solvent is replaced by a partial or excess of ammonium carboxylate salt, omitting the addition of the low boiling aprotic or inert protic solvent.
  10. 10. An air stable all-inorganic perovskite wafer detector produced by the production method according to any one of claims 1-9, wherein the detector comprises an all-inorganic perovskite wafer photoactive layer and patterned electrodes, and polypyrrole continuous conductive network is formed at the grain boundary of the all-inorganic perovskite wafer.

Description

Air-stable perovskite wafer detector and preparation method thereof Technical Field The invention belongs to the technical field of photoelectric sensing, and particularly relates to an air-stable perovskite wafer detector and a preparation method thereof. Background The all-inorganic perovskite is an ionic crystal with a chemical formula of ABX 3. Wherein the A-position is typically a monovalent inorganic cation such as Cs +, the B-position is a divalent metal cation such as Pb 2+、Sn2+、Ge2+, etc., and X is a monovalent halogen anion such as I -、Br-、Cl-, etc. as the introduction of volatile A-site organic cations (such as MA +、FA+ and the like) is avoided, compared with organic-inorganic hybrid perovskite, the organic-inorganic hybrid perovskite has higher thermal stability and environmental stability, has excellent photoelectric performance, and is widely focused in the fields of solar cells, light-emitting diodes, photoelectric detection and the like. Since 2015, the perovskite is applied to an X-ray detector for the first time, and the perovskite is gradually becoming a candidate material with competitiveness in the field of X-ray detection. However, all inorganic perovskite have ion migration problems inherent to ionic crystals. Meanwhile, compared with flexible organic-inorganic hybrid perovskite, the unique rigid structure of the perovskite can cause serious local lattice strain when ions migrate, promote the transition of the metastable state photoactive state towards the non-photoactive phase, and exacerbate the structural instability in the operation process. In X-ray detection applications, perovskite absorber layers are typically required to reach millimeter-scale thicknesses for efficient absorption of high energy photons. In order to ensure efficient extraction of carriers in this thickness of active layer, a high operating bias voltage must be applied. However, the synergistic effect of high voltage and high energy radiation can aggravate the ion migration phenomenon of the all-inorganic perovskite, and finally, the failure behaviors such as rapid decay of the sensitivity of the detector, signal drift and the like are initiated. Currently, the technical paths of improving the quality and inhibiting bulk ion migration of a polycrystalline wafer prepared by a hot pressing method are mainly divided into two methods of physical regulation and chemical modification. The physical method mainly regulates the Ostwald ripening process through the temperature, pressure and initial grain size of the perovskite powder of hot pressing, promotes grain growth and increases grain size, thereby constructing a wafer with low defect state density and enhancing the sensitivity and stability of the X-ray detector. Chemical approaches have focused on functional additives to regulate crystallization kinetics or to directly passivate grain boundaries. However, the prior arts have the problems that firstly, the additive (such as DMSO) used for promoting the crystallization quality of the hot pressed wafer can effectively regulate and control crystallization in the hot pressing process, but has certain biotoxicity, is easy to volatilize or remain in the synthesis and post-treatment processes, can cause potential pollution to soil and water environment due to improper disposal and does not meet the green electron manufacturing requirement, and secondly, the additive in the hot pressed perovskite wafer is mainly low-conductivity or insulating organic molecules such as 2-bromonaphthalene and TMTA in terms of passivating grain boundaries and can be effectively anchored at the grain boundary vacancy defects, but the effective transition of electrons/holes is inhibited while an ion migration barrier is constructed, so that the carrier collection efficiency is reduced, the sensitivity and the stability of a detector are difficult to be obtained, and thirdly, the chemical oxidation synthesis method of polypyrrole is a mature technology, but is directly carried out, There is a serious mismatch in simple grafting into perovskite hot pressing systems. the traditional polymerization conditions, such as oxidizing environment and an acidic initiation system, are extremely easy to cause chemical damage to the perovskite active layer, and the mixing difficulty of the liquid monomer and the solid powder makes it difficult to realize controllable in-situ polymerization at the crystal boundary, and in addition, the hot-pressing temperature of the perovskite is higher than the polymerization temperature of polypyrrole in the traditional process, so that the premature polymerization of the polypyrrole inhibits the growth of perovskite crystal grains. Therefore, there is a need to develop a synthesis strategy that is environmentally friendly and can simultaneously achieve ion migration passivation and electron/hole conduction to produce a high performance, highly stable all-inorganic perovskite wafer detector, Disclosure of Inve