Detection of the HOMO density of BEDT-TTF from the scanning tunneling microscopy study of β-(BEDT-TTF)2I3

The organic conducting salt β-(BEDT-TTF)2I3 (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene) was examined by scanning tunneling microscopy (STM) and by electronic band structure calculations. The observed STM images are consistent with the (011) surface of the salt and are in good agreement with the partial electron density plot calculated for the (011) surface. These studies show the detection of the highest occupied molecular orbital (HOMO) pπ-orbital density of BEDT-TTF by STM for the first time.