Superior performance of silver bismuth iodide photovoltaics fabricated via dynamic hot-casting method under ambient conditions

• Main Authors: Ghosh, Biplab, Wu, Bo, Guo, Xintong, Harikesh, Padinhare Cholakkal, John, Rohit Abraham, Baikie, Tom, Arramel, Wee, A. T. S., Guet, Claude, Sum, Tze Chien, Mhaisalkar, Subodh, Mathews, Nripan
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Materials::Energy materials; Bi-based Ternary Halides; Dynamic Hot Casting
• Online Access: https://hdl.handle.net/10356/137085; https://doi.org/10.21979/N9/OVZYOU
• Institution: Nanyang Technological University

Bismuth-based ternary halides have recently gained a lot of attention as lead-free perovskite materials. However, photovoltaic performances of these devices remain poor, mostly due to their low-dimensional crystal structure and large bandgap. Here, a dynamic hot casting technique to fabricate silver bismuth iodide-based perovskite solar cells under an ambient atmosphere with power conversion efficiencies above 2.5% is demonstrated. Silver bismuth iodides are 3D analogs of complex ternary bismuth halides with a suitable bandgap for a single junction solar cell. As far as it is known, these results represent the highest efficiency for solution processed air-stable lead-free perovskite solar cells. The enhanced solar cell performance via this dynamic hot casting technique can be attributed to long carrier lifetimes, micrometer-sized crystalline grains, and pinhole free thin-film formation with uniform morphology. This work provides a new direction for fabrication of solution-processed lead-free perovskite solar cells with a rapid fabrication strategy irrespective of the processing environment.