Alpha-sexthiophene/n− Si heterojunction diodes and solar cells investigated by I-V and C-V measurements

► The 6T/n−-Si junction has a current rectification characteristic explained by a Schottky heterojunction model. ► The Schottky barrier height and ideality factor were estimated to be 0.75-0.79 eV and 2.5, respectively. ► The depletion layer is generated solely in the n−-Si layer on a sub-micron scale. ► This heterojunction allows for power generation with power conversion efficiencies up to 0.4% with a simulated solar light exposure of 50 mW/cm2.