Unravelling the factors influencing halide perovskite based switchable photovoltaics

• Main Authors: Xing, Xuechao, Ng, Si En, Tay, Yeow Boon, Yantara, Natalia, Lew, Wen Siang, Mathews, Nripan
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2024
• Subjects: Physics; Other; Switchable photovoltaics; Halide perovskite; Ion migration; Metal contacts; Open circuit voltage
• Online Access: https://hdl.handle.net/10356/173935
• Institution: Nanyang Technological University

Lead halide perovskites have revolutionized the field of optoelectronics (such as photovoltaics and light emitting diodes) demonstrating extraordinary material properties despite being formed at low temperatures. However, ion migration in the bulk or at the interfaces results in stability issues especially in devices where metal electrodes directly interface with the perovskite film. Utilizing the switchable photovoltaic phenomenon (SPV) in halide perovskites as a measure of ion migration and electrochemical reactions within them, we evaluated Cs0.05MA0.15FA0.70PbI2.5Br0.5 triple cation perovskite, widely used in photovoltaics. We systematically measured the various factors determining the SPV, including electric field magnitudes, type of metal contacts, Illumination conditions, and temperature. This study reveals the roles of electrode work functions and reactivities on ion migration and local electronic structure modulation. ITO electrodes demonstrated the highest open-circuit voltage (Voc) about 0.85 V while Ag electrodes developed conductive filaments. However, the Voc distribution for Ti and Cr electrodes shows a more pronounced linear correlation with the poling electric field strength. Insights from this lateral design are directly relevant to transistor and memristor architectures and offer inputs into the design of perovskite-based photovoltaic/optoelectronic devices.