Enhanced efficiency in lead-free bismuth iodide with post treatment based on a hole-conductor-free perovskite solar cell

• Published in: Nano research Vol. 11; no. 12; pp. 6283 - 6293
• Main Authors: Shin, Jongmoon, Kim, Maengsuk, Jung, Sujeong, Kim, Chang Su, Park, Jucheol, Song, Aeran, Chung, Kwun-Bum, Jin, Sung-Ho, Lee, Jun Hee, Song, Myungkwan
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.12.2018; Springer Nature B.V
• Subjects: Atomic/Molecular Structure and Spectra; Band gap; Biomedicine; Biotechnology; Bismuth; Chemistry and Materials Science; Condensed Matter Physics; Conductors; Efficiency; Energy conversion efficiency; First principles; Iodides; Lead free; Materials Science; Nanotechnology; Optical properties; Perovskites; Photovoltaic cells; Photovoltaics; Research Article; Solar cells; Stability; Toxicity; lead free; perovskite; band-gap engineering; solar cells; bismuth halide
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-018-2151-4

Despite the excellent merits of lead perovskite solar cells, their instability and toxicity still present a bottleneck for practical applications. Bismuth perovskite has emerged as a candidate for photovoltaic (PV) applications, because it not only has a low toxicity but is also stable in air. However, the power conversion efficiency (PCE) remains an unsolved problem. We performed band gap tuning experiments to improve the efficiency. The absorption of ABi 3 I 10 structure films was extended within the visible region, and the optical band gap was decreased considerably compared to that for Cs 3 Bi 2 I 9 . Furthermore, we explained the correlation between the structure and the optical properties via a first-principles study. A device employing CsBi 3 I 10 as a photoactive layer exhibits a PCE of 1.51% and an excellent ambient stability over 30 days.