Solution-processed Ga-TiO₂ electron transport layer for efficient inverted organic solar cells

Abstract

To boost the charge transport and collection processes in inverted organic solar device, gallium (Ga) was added to conventional TiO₂ film to form the Ga-TiO₂ film. Compared to the pristine film, the Ga-TiO₂ film showed better energy level alignment, which is in good agreement with the heightened open-circuit voltage and fill factor. Attributed to the superior electron transport, the Ga-TiO₂ based solar cell achieved paramount power conversion efficiency (PCE) of 7.72%, while the pristine TiO₂ based solar cell showed lower PCE of 6.65%.