Modifications in Gap State Distribution Upon High Energy Electron Bombardment in n Type Hydrogenated Amorphous Silicon

Abstract

ABSTRACTModifications in the structural parameters of n type a-Si:H due to bombardment of different doses of 10 keV and 1 MeV electrons and the consequent changes in the gap state distribution are studied. A systematic dependance of the changes on the energy and dosage of electrons is observed. The Deep Level Transient Spectroscopy results reveal that apart from increasing the gap state density over a broad energy range, the electron bombardment also modifies the charge state of the defect, which is conclusively brought out by the result of C-V measurements. An understanding of the reason behind such modifications is sought by studying the structural parameters of the bombarded films directly with the help of Laser Raman Spectroscopy.