Efficient and stable all-inorganic perovskite solar cells based on nonstoichiometric CsₓPbI₂Brₓ (x > 1) alloys

• Main Authors: Frolova, Lyubov A., Chang, Qing, Luchkin, Sergey Yu., Zhao, Daming, Akbulatov, Azat F., Dremova, Nadezhda N., Ivanov, Andrey V., Chia, Elbert E. M., Stevenson, Keith J., Troshin, Pavel A.
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2021
• Subjects: Science::Physics; Highly Efficient; Thin-films
• Online Access: https://hdl.handle.net/10356/151643
• Institution: Nanyang Technological University

Here we report a systematic study of all-inorganic perovskite-inspired systems based on CsₓPbI₂Brₓ alloys with x ranging from 0.95 to 4. The identified optimal non-stoichiometric composition Cs₁.₂PbI₂Br₁.₂ delivered the best optoelectronic, structural and photovoltaic characteristics in combination with the improved stability. The elucidated remarkable effect of the Cs₄PbI₂Br₄ impurity phase, serving as a reservoir of CsBr, on the photothermal stability and photovoltaic performance of CsPbI₂Br perovskite films offers a new paradigm in the development of more efficient and stable all-inorganic perovskite solar cells.