The inverted PVSC device with PTN-Br as the cathode interlayer exhibits a reduced WF, better ohmic contact and improved electron mobility, leading to improved PCE. Due to the suitable UV absorption of PTN-Br, the device showed much-enhanced stability under UV radiation.
Controlling the grain size of the organic–inorganic perovskite thin films using thiourea additives now crossing 2 μm size with >20% power conversion efficiency.