A PbS nanocrystal-C60 photovoltaic device for infrared light harvesting

Abstract
PbSnanocrystal ( nc - Pb S ) - C 60 photovoltaic devices are demonstrated, in which nc-PbS function as electron donors, showing infrared photosensitivity up to 1600 nm . Annealing nc-PbS is proved to remove capping oleic acid ligands, studied using x-ray photoelectron spectroscopy, significantly improving the short circuit current, open circuit voltage, and fill factor. The device performance is rationalized by quantum confinement in nc-PbS and energy level alignment at the heterojunction based on direct measurements of nc-PbS ionization potential using ultraviolet photoelectron spectroscopy.