Electron-enriched thione enables strong Pb-S interaction for stabilizing high quality CsPbI perovskite films with low-temperature processing.

Cesium lead iodide (CsPbI) perovskite is a promising photovoltaic material with a suitable bandgap and high thermal stability. However, it involves complicated phase transitions, and black-phase CsPbI is mostly formed and stabilized at high temperatures (200-360 °C), making its practical application challenging. Here, for the first time, we have demonstrated a feasible route for growing high quality black-phase CsPbI thin films under mild conditions by using a neutral molecular additive of 4(1)-pyridinethione (4-PT).

Reliable Measurement of Perovskite Solar Cells.

Perovskite solar cells (PSCs) have undergone an incredibly fast development and attracted intense attention worldwide owing to their high efficiency and low-cost fabrication. However, it is challenging to make a reliable measurement of PSCs, which creates great difficulty for researchers to compare and reproduce published results. Herein, the major measurement methods and key factors affecting evaluation of PSCs are summarized, such as hysteresis in current-voltage measurement, calibration of solar simulators for less mismatch in spectra and light intensity, and the area for the calculation of current density and power conversion efficiency.