Organic photovoltaics with high stability sustained for 100 days without encapsulation fabricated using atomic layer deposition

Abstract

ZnO thin films with a rippled surface structure were used as electron-collecting layers of inverted organic photovoltaics (OPVs). Using additional ultrathin layers of ZnO and TiO 2 fabricated using atomic layer deposition (ALD), not only the power-conversion efficiency of the OPVs could be increased (up to 3.5%), but also the photovoltaic performance became nearly constant within 100 days without any additional encapsulations of the solar cells under ambient conditions. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Low stability is a hurdle to be overcome for application of organic photovoltaics (OPV). As described in this Letter, ultrathin layers of ZnO and TiO 2 fabricated using atomic layer deposition on ZnO electron-collecting layers of OPV could greatly enhance the photostability of OPV. Without any additional encapsulation of the solar cells under ambient conditions, no significant decrease in performance of the solar cells could be found for 100 days. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.