Enhance the efficiency of perovskite solar cells using W doped SnO2 electron transporting layer

Abstract For low temperature (≤180 °C) processed perovskite solar cells (PSCs), SnO 2 has been proven to be one of the most effective electron transporting layer. However, problems, such as poor electric conductivity and high defect density, inevitably exist in the SnO 2 films which are fabricated using low temperature solution methods. Element doping of SnO 2 film is a feasible strategy to alleviate the above problems. Herein, W doping of the SnO 2 is realized through addition of ammonium tungstate hydrate into the molecular precursor of SnO 2 . The W doped SnO 2 film exhibits higher conductivity, and can better extract and transport the electrons from the perovskite films. Hence, power conversion efficiency is boosted from 20.60 % for the reference PSCs to 21.83 % for PSCs fabricated on 2.5 mg mL −1 ammonium tungstate hydrate doped SnO 2 films.