Fabrication of Perovskite Uniform Film in Air via Introduction of Aniline Cations

Abstract

Alkylammonium lead(II) halide (APbX3) perovskite is developed to be the most potential light absorbing material in the photovoltaic field. However it is sensitive to water and oxygen, and the perovskite uniform film is difficult to be prepared in atmospheric environment. Here, CH3NH3PbI3 perovskite uniform layer was prepared in ambient environment via adding aniline cations in the methylamine deposition solution of the perovskite layer. XRD results indicate 3D crystalline structure of CH3NH3PbI3 perovskite is remained in the case of addition of the low concentration of aniline cations. With the addition increasing of aniline cations, 2D crystalline structure of (C6H5‐NH3)2PbI4 is gradually formed. SEM images indicate that the introduction of aniline cations obviously improves the coverage of CH3NH3PbI3 perovskite on nanocrystalline TiO2 thin film. The short circuit photocurrent and power conversion efficiency of perovskite solar cell based on the mixed perovskite were enhanced. The perovskite solar cell fabricated with the optimized molar ratio of aniline cations shows a short circuit photocurrent density of 17.1 mA⋅cm−2 and power conversion efficiency of 5.7%, which is 28% higher than that of the device based on pure CH3NH3PbI3 perovskite. The photovoltaic performance enhancement of perovskite solar cell is due to the formation of perovskite uniform layer as aniline cations are introduced, which suppresses the possible recombination processes.

Improving the Stability and Efficiency of Perovskite Solar Cells by a Bidentate Anilinium Salt

“…A weaker HB was reported to benefit the defect passivation of perovskite films . In addition, annilinium-based salts were found to improve the physical contact between the perovskite and the hole transport material (HTM), in the case of nip -type PSC . In both neutral and protonated molecules, the formation of HB with iodide is expected to heal ionic vacancies in the film. , …”