Author/Authors :
Cook، نويسنده , , Steffan and Ohkita، نويسنده , , Hideo and Kim، نويسنده , , Youngkyoo and Benson-Smith، نويسنده , , Jessica J. and Bradley، نويسنده , , Donal D.C. and Durrant، نويسنده , , James R.، نويسنده ,
Abstract :
The photophysical properties of [6,6]-phenyl C61 butyric acid methyl ester (PCBM) are found to differ depending on its concentration in thin films. A film of dispersed PCBM molecules in polystyrene (PS) showed only weak absorption in the visible region (400–700 nm) with a single S1 → S0 emission band at around 700 nm. By comparison, a film of pristine PCBM showed heightened absorption in the visible region and the presence of an additional higher energy emission at ∼500 nm assigned to the presence of charge transfer (CT) transitions in crystalline PCBM. The energy of the CT exciton is estimated to be ∼2.8 eV.
