Efficiency enhancement of semi-transparent sandwich type CH3NH3PbI3 perovskite solar cells with island morphology perovskite film by introduction of polystyrene passivation layer†
Highly semi-transparent sandwich type CH3NH3PbI3 (MAPbI3) island perovskite solar cells with high efficiency were constructed by introduction of a polystyrene (PS) passivation interlayer. The PS insulator can prevent direct contact between the TiO2 electron conductor and the polytriarylamine hole conductor. The PS passivation interlayer could be selectively deposited on bare TiO2 by a consecutive spin-coating and spin-washing process. The average visible transmittance of semi-transparent sandwich type MAPbI3 island perovskite solar cells with and without PS passivation layer was ∼20.9% and ∼18.6%, respectively; its power conversion efficiency was 10.2% for forward scan condition and 10.6% for reverse scan condition (average = 6.17% ± 2.32% for 40 samples) and 5.9% for forward scan condition and 6.6% for reverse scan condition (average = 2.93% ± 1.57% for 40 samples); and its efficiency degradation for 30 days was ∼5% and ∼9%, respectively.