Study on Photoelectric Conversion Properties for Near‐infrared Absorbing Materials

Abstract The feasibility of near‐infrared (NIR) absorbing material Cs 0.33 WO 3 to transform NIR to photocurrent in a solid‐state device is reported. The electrical properties and energy levels of Cs 0.33 WO 3 and the impedance of the devices are analyzed in detail to realize the photovoltaic transformation mechanism further. Polyvinylpyrrolidone incorporation into the Cs 0.33 WO 3 layer can effectively suppress electron‐hole recombination and raise the photocurrent density from 2.5 to 22.2 (a 788% increase), which is much larger than that in a liquid‐electrolyte device. Poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) used as a hole transport material can lead to a lower energy barrier and faster response than NiO X , but resulting in worse device stability.