Understanding the temperature sensitivity of the photovoltaic parameters of perovskite solar cells

Perovskite solar cells (PSCs) have promised high-efficiency and low-cost solar-to-electrical conversion that now go outdoors for practical applications; however, the elevated outdoor temperature remarkably affects the photovoltaic efficiency. To date, there has been little work about understanding the temperature sensitivity of PSCs. Here, we build an analytical model to understand the temperature sensitivity and the limiting factors of temperature coefficient (TC) in PSCs. Our model is based on diffusion-drift numerical method by involving the temperature-dependent bandgap and band edge of perovskite layers, which quantitively describe the effect of many physical factors, including carrier recombination channels, trap density, band alignment and band variation of transport layers. It was found that the built-in electrical field and minority carrier concentration at interface are closely corrected with temperature, that is responsible for the temperature sensitivity of device performance. We show that this model can be used to explain the disparate temperature sensitivity of a series of reported real PSCs, and also gives potential pathways for the design and fabrication of temperature-insensitive photovoltaics towards practical applications.