Nanoscale Imaging of Charge Carrier and Exciton Trapping at Structural Defects in Organic Semiconductors

Charge carrier and exciton trapping in organic semiconductors crucially determine the performance of organic (opto-)electronic devices such as organic field-effect transistors, light-emitting diodes, or solar cells. However, the microscopic origin of the relevant traps generally remains unclear, as most spectroscopic techniques are unable to simultaneously probe the electronic and morphological structure of individual traps. Here, we employ low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS) as well as tight-binding calculations derived from ab initio calculations to image the localized electronic states arising at structural defects in thin C-60 films (