Improved stability and efficiency of inverted triple-cation mixed-halide perovskite solar cells with CsI-modified NiOx hole transporting layer

Ching-Ho Tien; Yu-Chen Liu; Thangaraji Vasudevan; Lung-Chien Chen

doi:10.1016/j.heliyon.2024.e25352

Improved stability and efficiency of inverted triple-cation mixed-halide perovskite solar cells with CsI-modified NiOx hole transporting layer

Heliyon. 2024 Jan 28;10(3):e25352. doi: 10.1016/j.heliyon.2024.e25352. eCollection 2024 Feb 15.

Authors

Ching-Ho Tien¹, Yu-Chen Liu², Thangaraji Vasudevan², Lung-Chien Chen²

Affiliations

¹ Department of Semiconductor Engineering, Lunghwa University of Science and Technology, No. 300, Sec. 1, Wanshou Rd., Taoyuan, 33306, Taiwan.
² Department of Electro-Optical Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei, 10608, Taiwan.

Abstract

Addressing the critical challenge of mitigating defect generation and enhancing the extended durability of perovskite solar cells (PeSCs) requires effective passivation materials. In our study, we investigated the impact of varying concentrations of cesium iodide (CsI), an alkali halide, on the interface layer among the hole transporting layer (HTL) and the perovskite film in a triple-cation lead hybrid halide Cs_0.15FA_0.81MA_0.04Pb(I_2.86Br_0.14)₃ perovskite layer. Our findings revealed that the introduction of CsI into the NiOx HTL led to improved crystallinity and a reduction in defects within the perovskite film. Consequently, the photovoltaic performance of the CsI-modified PeSC exhibited a notable enhancement. Specifically, the photoelectric conversion efficiency (PCE) increased from 18.7 % in the original PeSC, which lacked CsI modification, to 20.5 %. Moreover, this improvement in PCE was accompanied by excellent stability, with the CsI-modified PeSC retaining 80 % of its opening PCE even afterward 144 h of testing.

Keywords: CsI; Interface engineering; Passivation; Perovskite solar cell; Perovskites.