Search

CN-121985715-A - Perovskite thin film material and preparation method thereof

CN121985715ACN 121985715 ACN121985715 ACN 121985715ACN-121985715-A

Abstract

The invention relates to the technical field of photoelectric materials, in particular to a perovskite thin film material and a preparation method thereof. The thin film material comprises a conductive substrate, and a narrow band gap perovskite layer, a middle interface modification layer and a wide band gap perovskite layer which are sequentially coated on the conductive substrate from bottom to top, wherein the chemical general formula of the narrow band gap layer is MA m FA n Pb 1‑ c Ge c I 3‑γ Br γ , the chemical general formula of the wide band gap layer is FA x Cs y Pb 1‑a M a I 3‑β Br β , and the middle interface modification layer is formed by compounding thioglycollic acid and nano titanium dioxide. The material realizes 400-1100nm wide spectrum high-efficiency absorption by the synergistic effect of lamination band gap complementation, ion doping and composite interface modification, remarkably reduces defect state density, improves photoelectric conversion efficiency and long-term stability, and provides key technical support for perovskite solar cell industrialization.

Inventors

  • LI TAO
  • ZHU LIANGLIANG
  • SHEN JI
  • WANG XIAOJUAN
  • MO LINGLING

Assignees

  • 兰州石化职业技术大学

Dates

Publication Date
20260505
Application Date
20260113

Claims (10)

  1. 1. The perovskite thin film material is characterized by comprising a conductive substrate, and a narrow-band-gap perovskite layer, a middle interface modification layer and a wide-band-gap perovskite layer which are sequentially coated on the conductive substrate from bottom to top; the conductive substrate is one of FTO glass, ITO glass or PET/ITO, PEN/ITO and PI/ITO flexible substrates; The chemical general formula of the narrow-band gap perovskite layer is MA m FA n Pb 1-c Ge c I 3-γ Br γ , wherein MA is methylamine ion, FA is formamidine ion, ge is germanium ion, m is more than or equal to 0.5 and less than or equal to 0.7,0.3 and less than or equal to 0.5, n is more than or equal to m+n=1, c is more than or equal to 0.01 and less than or equal to 0.10, and gamma is more than or equal to 0.01 and less than or equal to 0.1; the intermediate interface modification layer is formed by compositing thioglycollic acid and nano titanium dioxide; The chemical general formula of the wide-band-gap perovskite layer is FA x Cs y Pb 1-a M a I 3-β Br β , wherein FA is formamidine ion, cs is cesium ion, x is more than or equal to 0.7 and less than or equal to 0.9, y is more than or equal to 0.1 and less than or equal to 0.3, x+y= 1;M is Sn 2+ or Zn 2+ , a is more than or equal to 0.05 and less than or equal to 0.15, and beta is more than or equal to 0.2 and less than or equal to 0.4.
  2. 2. The perovskite thin film material according to claim 1, wherein the mass ratio of thioglycollic acid to nano titanium dioxide in the intermediate interface modification layer is 1:5-20.
  3. 3. The perovskite thin film material of claim 1, wherein the thickness of the wide bandgap perovskite layer is 100-300nm, the thickness of the intermediate interface modification layer is 5-20nm, and the thickness of the narrow bandgap perovskite layer is 200-500nm.
  4. 4. A method of producing a perovskite thin film material as claimed in any one of claims 1 to 3, comprising the steps of: (1) Sequentially placing the substrate into deionized water, absolute ethyl alcohol and acetone, ultrasonically cleaning for 10-20min, then drying by nitrogen, placing into an ozone cleaning machine, treating for 10-20min to obtain a pretreated substrate, and placing into a glove box for standby; (2) Adding iodomethylamine, iodoformamidine, lead iodide, germanium diiodide and lead bromide into an N, N-dimethylformamide/dimethyl sulfoxide mixed solution to prepare a narrow-band gap perovskite precursor solution with the total concentration of 1mol/L, heating to 50-70 ℃, stirring for reacting for 1-3 hours, filtering by a 0.22 mu m filter membrane, spin-coating on a pretreated substrate in a glove box, wherein the first-stage rotating speed is 400-600r/min for 5-10s, the second-stage rotating speed is 3000-5000r/min for 20-40s, dropwise adding isopropanol after the second-stage rotating speed is started for 10s, immediately transferring the substrate into a program-controlled temperature annealing furnace after spin-coating is completed, setting the heating rate to 3-7 ℃, heating to 100-120 ℃, preserving heat for 10-30min, and naturally cooling to room temperature to obtain a narrow-band gap perovskite layer; (3) Adding nano titanium dioxide into absolute ethyl alcohol, performing ultrasonic dispersion for 10-30min, adding thioglycollic acid, stirring for 1-2h at room temperature, then spin-coating on a pretreated substrate containing a narrow band gap perovskite layer in a glove box at a rotating speed of 3000-4000r/min for 30-60s, transferring into a vacuum drying oven after spin-coating is completed, transferring into an annealing furnace after drying, setting a heating rate of 3-7 ℃ per min, and performing heat preservation for 5-10min after rising to 80-100 ℃ to obtain an intermediate interface modification layer; (4) Adding amitraz, cesium iodide, lead iodide, MI 2 and lead bromide into an N, N-dimethylformamide/dimethyl sulfoxide mixed solution to prepare a wide-bandgap perovskite precursor solution with the total concentration of 1mol/L, heating to 60-80 ℃, stirring for reacting for 2-3 hours, filtering by a 0.22 mu m filter membrane, spin-coating on a pretreatment substrate with an intermediate interface modification layer and a narrow-bandgap perovskite layer in a glove box, wherein the first-stage rotating speed is 500-700r/min for 5-15s, the second-stage rotating speed is 3000-4000r/min for 20-30s, the second-stage rotating speed is 10s after the beginning, dripping isopropanol, transferring into a program temperature-controlled annealing furnace after spin-coating is completed, setting the heating rate to 3-7 ℃ per min, heating to 110-130 ℃ and then preserving heat for 20-30min, and naturally cooling to room temperature to obtain a wide-bandgap perovskite layer; (5) Transferring the pretreated substrate containing the wide-band-gap perovskite layer, the intermediate interface modification layer and the narrow-band-gap perovskite layer into a glove box, carrying out ultraviolet irradiation treatment, carrying out secondary annealing in an argon atmosphere, and cooling to room temperature to obtain the perovskite film material.
  5. 5. The method according to claim 4, wherein the substrate in (1) has a size of 10 cm. Times.10 cm, and the concentration of ozone in the ozone cleaning machine is 80-100mg/m 3 .
  6. 6. The method for preparing a perovskite thin film material according to claim 4, wherein the molar ratio of iodomethylamine, iodoformamidine, lead iodide, germanium diiodide and lead bromide in (2) is 0.5-0.7:0.3-0.5:0.85-0.985:0.01-0.1:0.005-0.05, the volume ratio of N, N-dimethylformamide and dimethyl sulfoxide in the mixed solution of N, N-dimethylformamide/dimethyl sulfoxide is 4:1, and the dropping amount of isopropanol is 0.3-0.7g.
  7. 7. The method for producing a perovskite thin film material according to claim 4, wherein the weight ratio of nano titanium dioxide to ethanol in (3) is 1:40-60.
  8. 8. The method for preparing a perovskite thin film material according to claim 4, wherein the molar ratio of iodoformamidine, cesium iodide, lead iodide, MI 2 and lead bromide in (4) is 0.7-0.9:0.1-0.3:0.65-0.85:0.05-0.15:0.1-0.2, the volume ratio of N, N-dimethylformamide and dimethyl sulfoxide in the N, N-dimethylformamide/dimethyl sulfoxide mixed solution is 3:1, and the dropping amount of isopropanol is 0.3-0.5g.
  9. 9. The method for producing a perovskite thin film material according to claim 4, wherein the ultraviolet irradiation treatment in (5) is carried out under the conditions of a wavelength of 365nm, a power of 10mW/cm 2 and an irradiation time of 10 to 20 minutes.
  10. 10. The method for producing a perovskite thin film material according to claim 4, wherein the secondary annealing condition in (5) is a temperature rising rate of 2-5 ℃ per minute, a temperature of 100-120 ℃ and a heat preservation period of 5-15 minutes.

Description

Perovskite thin film material and preparation method thereof Technical Field The invention relates to the technical field of photoelectric materials, in particular to a perovskite thin film material and a preparation method thereof. Background The perovskite solar cell has become a research hot spot in the field of new energy photoelectric materials by virtue of excellent photoelectric conversion efficiency, low preparation cost and flexible film forming property, and has wide application prospects in photovoltaic industry upgrading and energy structure transformation. The perovskite material has the core advantages that the controllability of the crystal structure of the ABX 3 is realized, the accurate regulation and control of the band gap width within the range of 1.2-2.3eV can be realized by regulating the A, B, X-bit ion component, and a foundation is provided for the utilization of broad spectrum solar energy. In recent years, the photoelectric conversion efficiency of a single perovskite solar cell has been significantly broken through, but is limited by the absorption limitation of a single band gap to solar spectrum, the efficiency improvement gradually approaches to the theoretical limit, and the laminated structure design is pushed to be a key direction for breaking through the bottleneck. However, the existing perovskite thin film materials and lamination techniques still face a number of core technical bottlenecks. On one hand, the traditional laminated structure mostly adopts a double-laminated design, has poor band gap gradient matching property, is difficult to realize the full-band efficient absorption of 400-1100nm solar spectrum, has lower energy utilization rate of near infrared and ultraviolet bands, and meanwhile, has poor effective modification and connection mechanism at an interlayer interface, so that charge transmission is blocked, non-radiation recombination is serious, and interface defects become key factors for limiting efficiency and stability. On the other hand, the perovskite material is easy to change phase due to the influence of temperature and humidity environment in the crystal structure, a single cation system or doping strategy is difficult to consider high light absorption coefficient and structural stability, so that the efficiency attenuation of the material is remarkable in long-term use, and in addition, the existing interface modification material is mostly single-function type, so that the synergistic effect of defect blocking, charge transmission and environmental blocking cannot be realized at the same time. In the aspect of preparation technology, the preparation of the existing high-efficiency perovskite thin film often depends on high-temperature annealing (more than or equal to 150 ℃) and a precise spin coating technology, so that the energy consumption is high, large-area uniform film formation is difficult to realize, and the industrialized application process is restricted. Meanwhile, the suitability of the precursor solution proportion, film forming conditions and post-treatment flow in the traditional process is insufficient, so that uneven crystallinity of the film and higher defect state density are easily caused, and the consistency and reliability of the device performance are further affected. Therefore, the laminated perovskite thin film material with the characteristics of broad spectrum absorption, high stability and large-scale preparation potential is developed, and the problems of incomplete spectrum coverage, poor interface compatibility, insufficient stability and the like in the prior art are solved by optimizing component doping, interface modification and preparation process, so that the laminated perovskite thin film material has become an urgent need for promoting the industrial development of perovskite solar cells. Disclosure of Invention The invention aims to solve the defects in the prior art, and provides a perovskite thin film material and a preparation method thereof. Based on the above object, the invention provides a perovskite thin film material, which comprises a conductive substrate, and a narrow-band gap perovskite layer, an intermediate interface modification layer and a wide-band gap perovskite layer which are sequentially coated on the conductive substrate from bottom to top; the conductive substrate is one of FTO glass, ITO glass or PET/ITO, PEN/ITO and PI/ITO flexible substrates; The chemical general formula of the narrow-band gap perovskite layer is MA mFAnPb1-cGecI3-γBrγ, wherein MA is methylamine ion, FA is formamidine ion, ge is germanium ion, m is more than or equal to 0.5 and less than or equal to 0.7,0.3 and less than or equal to 0.5, n is more than or equal to m+n=1, c is more than or equal to 0.01 and less than or equal to 0.10, and gamma is more than or equal to 0.01 and less than or equal to 0.1; the intermediate interface modification layer is formed by compositing thioglycollic acid and nano titanium