Single crystal structure and opto-electronic properties of oxidized Spiro-OMeTAD

Single crystals of Spiro(TFSI)(2) were grown, the optical and electronic properties were characterized and compared with neutral Spiro-OMeTAD. Density-functional theory was used to get insights into binding and band structure properties. The flat valence bands indicate a rather limited orbital overlap in Spiro(TFSI)(2).