(Invited) Understanding the Photochemistry of Perovskites for Photovoltaics

Thanks to their high absorption coefficient and ideal band-gap [1], lead halide perovskite materials are good candidates for the next generation of solar cells with an impressive certified power conversion efficiency of >26% [2]. However, the development of perovskite based solar cells is impeded, in some architectures, by obstacles including degradation of the perovskite layer by light, oxygen, and moisture. Photoluminescence (PL) is a measure of photoexcited carrier radiative recombination and is thus a great tool for studying charge carrier processes in solar cells as the later operates through the absorption of light. However, measuring the steady state and time-resolved photoluminescence (PL) of perovskite thin-films is not as straightforward as initially thought, highlighting the sometimes-surprising nature of these materials. [3-5] This has implications for the use of these materials in photovoltaics and LEDs. We will discuss our utilisation of PL studies to understand the stability and performance of perovskite materials. The impact of the incorporation of nanomaterials into perovskite devices will be discussed along with the opportunities and challenges this affords in terms of sustainability and performance. We will discuss the work of The Applied Photochemistry Group at the SPECIFIC Innovation and Knowledge Centre, Swansea University, which aims to develop an understanding of the photostability and photochemistry of materials and devices to advance performance, sustainability, and design for circular economy. Yang, WS; Park, BW; Jung, EH; Jeon, NJ; Kim, YC; Lee, DU; Shin, SS; Seo, J; Kim, EK; Noh, JH; Seok, SI. Science, 2017, 356 (6345), 1376-1379. Best Research-Cell Efficiency Chart | Photovoltaic Research | NREL. [Online]. Péan, EV; De Castro, CS; Davies, ML. Materials Letters , 2019, 243 , 191-194. Péan, EV; Dimitrov, S; De Castro, CS; Davies, ML. Phys. Chem. Chem. Phys ., 2020, 22 , 28345-28358. Péan, EV; Davies, ML. J. Chem. Inf. Model. 2023, 63 , 15, 4477–4482