Effect of electron transport layer crystallinity on the transient characteristics of inverted organic solar cells

Abstract

We present how the crystallinity of the electron transport layer can dramatically influence the transient characteristics of organic solar cells. We employed an inverted cell structure using TiOx prepared by atomic layer deposition as an electron transport layer. The device possessing the amorphous phase TiOx exhibited a continuous increase in the device characteristics upon continuous illumination at ambient, which is attributed to the filling of shallow electron traps within the amorphous phase TiOx upon illumination. In contrast, the characteristics of the device with the crystalline phase TiOx showed a negligible increase upon continuous illumination.