Enhanced Charge Extraction of Li-Doped TiO(2) for Efficient Thermal-Evaporated Sb(2)S(3) Thin Film Solar Cells

We provided a new method to improve the efficiency of Sb(2)S(3) thin film solar cells. The TiO(2) electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb(2)S(3) solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO(2) films. Compared with the undoped TiO(2), Li-doped mesoporous TiO(2) dramatically improved the photo-voltaic performance of the thermal-evaporated Sb(2)S(3) thin film solar cells, with the average power conversion efficiency (PCE) increasing from 1.79% to 4.03%, as well as the improved open-voltage (V(oc)), short-circuit current (J(sc)) and fill factors. The best device based on Li-doped TiO(2) achieved a power conversion efficiency up to 4.42% as well as a V(oc) of 0.645 V, which are the highest values among the reported thermal-evaporated Sb(2)S(3) solar cells. This study showed that Li-doping on TiO(2) can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb(2)S(3)-based solar cells.