Nanocrystalline gallium nitride electron transport layer for cesium lead bromide photovoltaic power converter in blue light optical wireless power transmission

Abstract Nanocrystalline gallium nitride (nc-GaN) layers were deposited by RF magnetron sputtering for the electron transport layer of the cesium lead bromide (CsPbBr 3 ) photovoltaic power converter. We investigated the structural and electrical properties of the nc-GaN layers and found that substrate heater temperature is a key factor to determine the electrical conductivity of the nc-GaN layers. CsPbBr 3 photovoltaic power converters with nc-GaN electron transport layers show good photovoltaic performance. The best performance was obtained at the substrate heater temperature of 550 °C and a conversion efficiency of 5.56% ( V OC = 1.24 V, J SC = 6.68 mA cm −2 , FF = 0.66) under AM1.5 G illumination with a light intensity of 100 mW cm −2 . The estimated conversion efficiency under blue light with a wavelength of 450 nm is 28.8%.