Overcoming the Light‐Soaking Problem in Inverted Polymer Solar Cells by Introducing a Heavily Doped Titanium Sub‐Oxide Functional Layer

Abstract

Light-soaking-free inverted polymer solar cell (i-PSC) devices are demonstrated by incorporating nitrogen doped sol–gel titanium sub-oxide (N-TiOx). A heavily doped electron transport layer in i-PSCs, N-TiOx on indium tin oxide, yields an Ohmic contact with the bulk heterojunction layer that does not exhibit light-soaking processes. This results in highly efficient i-PSCs with power conversion efficiencies of 8.8%.