Inverted organic solar cells based on aqueous processed ZnO interlayers at low temperature

Abstract

A facile solution processable and low temperature (≤150 °C) approach was developed to deposit ZnO electron transport interlayers for inverted organic solar cells. The ZnO thin films were fabricated from the stable and non-toxic aqueous precursor solutions of ammine-hydroxo zinc complex, [Zn(NH3)x](OH)2. The resulting inverted poly (3-hexylthiophene): [6-6]-phenyl C61 butryric acid methyl ester solar cells exhibited power conversion efficiency of 4.17% as well as decent stability. We demonstrate that the work function of the ZnO electron transport interlayers was critical in terms of governing the photovoltaic performance of the inverted devices.