Thermally evaporable 5,10-dihydroindeno[2,1-a]indenes form efficient interfacial layers in organic solar cells

Abstract

In this study, we synthesized several bis(diarylamino)dihydroindenoindene derivatives for use as small-molecule hole transporting materials (HTMs) in organic photovoltaics. Because of their photophysical, electrochemical, and morphological properties, as well as their surface energies and device structures, these barely soluble HTMs prohibited interfacial mixing during the subsequent deposition through spin-coating of the active layer. An optimized device having the structure indium tin oxide/HTM/P3HT:PCBM/Ca/Al operated with a fill factor of 67.8%.