SUB-GAP AND BAND EDGE OPTICAL ABSORPTION IN a-Si:H BY PHOTOTHERMAL DEFLECTION SPECTROSCOPY

Abstract

Using photothermal deflection spectroscopy, we have investigated the optical absorption of various a-Si:H films in the range of 2.1-0.6 eV. An absorption shoulder which depends on deposition conditions and on doping was found and was attributed to dangling bonds. We also observed that the exponential edge broadens with increasing spin density