A New Method for Measuring Thin Film Stress Under Operational Conditions to Understand Perovskite Solar Cell Degradation

Understanding perovskite degradation and stress responses under practical conditions is necessary to design efficient and stable photovoltaic devices. This experiment creates an in-situ stress testing system, in which the stress of a sample may be tested while it is subjected to conditions that it may experience in operation, such as cycles of sunlight. This immediate stress response is valuable in understanding what factors directly contribute to the stresses that degrade perovskite solar cells. Perovskite may be 2D or 3D and are composed of many different elements and additives. Each ink responds differently to sunlight exposure due to their different structures, which is important to characterize and comprehend. Preliminary testing and characterization for 2D, 3D and MAPI with gellan gum additive perovskite inks is conducted in this experiment. It is reported that the lattice expansion causing degradation-inducing stress is due to photon dosage rather than heat, and both 3D and 2D perovskites are sensitive to minute photon dosage.