CN-121985718-A - Passivation additive for improving perovskite defects, perovskite film and preparation method of perovskite film

Abstract

The invention discloses a passivation additive for improving perovskite defects, a perovskite film and a preparation method thereof. According to the invention, moroxydine hydrochloride is added into the perovskite precursor solution, so that the crystallization process of the perovskite film can be regulated and controlled, defects are passivated, the obtained perovskite film has large and uniform grain size, few gaps among grains, high film density and few non-radiative recombination defects in the film, the survival life of carriers is greatly prolonged, the non-radiative recombination loss of the carriers is greatly reduced, and the photoelectric performance of the wide-bandgap perovskite is effectively improved.

Inventors

• LI WEI
• Luo Yueyao
• LIU YUHUI
• DU HONGQIANG

Assignees

• 武汉理工大学

Dates

Publication Date

20260505

Application Date

20260130

Claims (10)

1. 1. A passivating additive for improving perovskite defects, which is characterized in that the passivating additive is moroxydine hydrochloride.
2. 2. A perovskite thin film comprising the passivation additive of claim 1.
3. 3. A method for preparing a perovskite film according to claim 2, which is characterized by comprising the specific steps of adding moroxydine hydrochloride into a perovskite precursor solution, vibrating uniformly, spin-coating the perovskite film onto a substrate, dripping an antisolvent in the later stage of spin-coating, and annealing the substrate to obtain the perovskite film with high crystallinity on the surface of the substrate.
4. 4. The method for preparing a perovskite thin film according to claim 3, wherein the solute in the perovskite precursor solution is a perovskite material precursor with an ABX 3 structure, wherein a is one or more of CH 3 NH 3 + 、HC(NH 2 ) 2 + 、Cs + or Rb + , B is at least one of Pb 2+ 、Sn 2+ , and X is at least one of I - 、Br - 、Cl - .
5. 5. The method for preparing a perovskite thin film according to claim 4, wherein the perovskite precursor solution is prepared by dissolving methyl ammonium chloride, formamidine iodine, cesium iodide, lead chloride, lead bromide and lead iodide in a mixed solvent according to the chemical proportion of Cs 0.21 FA 0.76 MA 0.03 )Pb(Cl 0.06 Br 0.14 I 0.80 ) 3 , wherein the mixed solvent is a mixed solution of N, N-dimethylformamide and dimethyl sulfoxide according to the volume ratio of 3-4:1.
6. 6. The method for producing a perovskite thin film according to claim 5, wherein the concentration of methyl ammonium chloride in the perovskite precursor solution is 2.7 to 3.0g/L.
7. 7. The method for preparing the perovskite thin film according to claim 3, wherein the mass-volume ratio of moroxydine hydrochloride to the perovskite precursor solution is 0.5-5mg/mL, and the shaking process condition is that shaking is carried out for 1-5 hours at a frequency of 1000-3000 times/min until the solute is completely dissolved.
8. 8. The method for preparing a perovskite thin film according to claim 3, wherein the anti-solvent is added dropwise in the latter stage of spin coating, wherein the specific process conditions are that spin coating is carried out at a speed of 3000-6000rpm for 20-60 seconds, and the anti-solvent is added dropwise 3-10 seconds before the spin coating is finished.
9. 9. The method for preparing the perovskite thin film according to claim 3, wherein the annealing process conditions are that the perovskite thin film is preserved for 10-60 minutes at 80-150 ℃ under the protection of inert atmosphere, and then cooled to room temperature along with a furnace.
10. 10. A perovskite solar cell, comprising a transparent conductive substrate, a hole transport layer, the perovskite thin film of claim 2, a perovskite upper surface passivation layer, an electron transport layer, a buffer layer and an electrode layer which are sequentially stacked.

Description

Passivation additive for improving perovskite defects, perovskite film and preparation method of perovskite film Technical Field The invention belongs to the technical field of passivation of structural parts of an organic solid-state device, and particularly relates to a passivation additive for improving perovskite defects, a perovskite film and a preparation method of the perovskite film. Background Solar energy is considered as the new energy source with the most development potential in the twentieth century. Perovskite is attracting attention as a light absorbing material of a new generation of photovoltaic devices due to high efficiency, and through the development of over ten years, the international authentication efficiency of single junction perovskite solar cells is approaching that of crystalline silicon solar cells. However, perovskite photovoltaic cells have poor long-term stability and become a critical obstacle to their commercial application. The core problems of the perovskite type organic compound crystal are mainly characterized in that on one hand, the thermal stability of A-site organic cations (such as formamidine ions FA + and methylammonium ions MA +) in a perovskite crystal structure is weak, inorganic Pb-I octahedral frameworks collapse due to easy volatilization so as to promote decomposition of an optically active phase, and on the other hand, a large number of intrinsic defects such as vacancies and interstitial atoms are easy to form in a crystal lattice in the crystallization process, and the defects can induce non-radiative recombination of carriers, greatly reduce the open-circuit voltage of a device and also serve as channels for ion migration. Particularly, under the induction of external conditions such as illumination, thermal fields, water vapor and the like, halogen ions (I -、Br-、Cl-) are extremely easy to migrate and segregate, so that the photoelectric performance of the material is quickly attenuated. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a passivation additive for improving perovskite defects, a perovskite film and a preparation method thereof, and the passivation additive is introduced into a perovskite precursor solution to regulate and control crystal nucleation and growth, improve crystal quality, passivate defects by utilizing molecular structure characteristics of the perovskite precursor solution, inhibit ion migration and further improve photoelectric conversion efficiency and stability of a device. In a first aspect, the invention provides a passivating additive for improving perovskite defects, wherein the passivating additive is moroxydine hydrochloride. In a second aspect the present invention provides a perovskite thin film comprising a passivation additive as described above. The grain boundaries of the perovskite thin film contain moroxydine hydrochloride molecules that interact with the perovskite crystals through their functional groups. The third aspect of the invention provides a preparation method of the perovskite film, which comprises the specific steps of adding moroxydine hydrochloride into a perovskite precursor solution, vibrating uniformly, spin-coating onto a substrate, dripping an anti-solvent in the later stage of spin-coating, and annealing the substrate to obtain the perovskite film with high crystallinity on the surface of the substrate. According to the scheme, the solute in the perovskite precursor solution is a perovskite material precursor with an ABX 3 structure, wherein A is CH 3NH3+ (MA +）、HC(NH2)2+ (one or more of FA +）、Cs+ or Rb +; B is at least one of Pb 2+、Sn2+; and X is at least one of I -、Br-、Cl-). Preferably, the perovskite precursor solution is obtained by dissolving methyl ammonium chloride (MACl), formamidine iodine (FAI), cesium iodide (CsI), lead chloride (PbCl 2), lead bromide (PbBr 2) and lead iodide (PbI 2) in a mixed solvent according to the stoichiometry of Cs 0.21FA0.76MA0.03)Pb(Cl0.06Br0.14I0.80)3. According to the scheme, the mixed solvent is a mixed solution of N, N-Dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) according to the volume ratio of 3-4:1. According to the scheme, the concentration of the methyl ammonium chloride in the perovskite precursor solution is 2.7-3.0g/L. According to the scheme, the mass volume ratio of moroxydine hydrochloride to the perovskite precursor solution is 0.5-5mg/mL. According to the scheme, the oscillation process conditions are that the oscillation is carried out for 1-5 hours at the frequency of 1000-3000 times per minute until the solute is completely dissolved. According to the scheme, the anti-solvent is dripped in the later period of spin coating, and the specific process conditions are that spin coating is carried out for 20-60 seconds at a rotating speed of 3000-6000rpm, and the anti-solvent is dripped in 3-10 seconds before the spin coating is finished. According to the scheme, the antisolvent is ethyl ac