PHOTOEMISSION AND INVERSE-PHOTOEMISSION STUDIES ON A THIN-FILM OF N,N'-DIMETHYLPERYLENE-3,4,9,10-BIS(DICARBOXIMIDE)

Ultraviolet photoemission (PE) and inverse photoemission (IPE) spectra were measured for thin films of N,N'-dimethylperylene-3,4,9,10-bis(di carboximide) (DM-PBDCI) and perylene-3,4,9,10-tetracarboxylic dianhydr ide (PTCDA), the former known as an n-type organic semiconductor and t he semiconducting nature of the latter still unidentified. The electro nic structure around the energy gap, obtained from the combination of PE and IPE spectra observed, is found to be almost the same for the tw o compounds, indicating that PTCDA could be assigned as an n-type semi conductor. (C) 1998 Elsevier Science B.V.