[17p-K405-1~8] 12.5 Organic and hybrid solar cells

2:30 PM - 2:45 PM JST(5:30 AM - 5:45 AM UTC)English Presentation

[17p-K405-6] Effect of Alkali metal halide additive on AgBiI₄ lead-free solar cell

〇Shanas Fatima^1,2, Sunil Kumar Singh¹, Khadka B Dhruba², Yasuhiro Shirai² (1.Dept. of Phy. IIT BHU, 2.NIMS, Tsukuba, Japan)

Keywords:

lead free solar cell,additive engineering

Halide perovskites have achieved high power conversion efficiencies (PCEs) exceeding 26% for single-junction devices. However, their use is limited by lead toxicity and poor stability against moisture, air, and temperature. To address these issues, ternary Ag-Bi-I materials (rudorffites) have emerged as Pb-free alternatives, offering lower toxicity and better stability. Despite their promise, the PCE of rudorffite-based solar cells remains low. In this study, we investigate the effect of NaI additives on AgBiI₄, a Pb-free material with a bandgap of ∼1.84 eV. The NaI additive improves crystallization, resulting in compact, pinhole-free films. Devices with an ITO/SnO₂/AgBiI_4-NaI/PTAA/Ag configuration achieved a PCE of 3.72%, among the best for rudorffite solar cells (Fig. 1). NaI also reduced Bi⁰ ions, suppressed non-radiative relaxations (evidenced by increased PL intensity and lifetime), and improved device stability. This work highlights the role of additive engineering in enhancing rudorffite solar cell performance.