The distribution of deep states in undoped a-Si:H is investigated. For this purpose, a new experimental technique is introduced which is based on the principle of thermally-stimulated space-charge relaxation. A peak in the density of states is resolved at - 0.6 eV below the mobility edge of the conduction band. The energy position and magnitude of this peak are found to be consistent with space-charge-limited current measurements.
"The Distribution Of Deep States In Hydrogenated Amorphous Silicon", Proc. SPIE 0763, Physics of Amorphous Semiconductor Devices, (21 August 1987); doi: 10.1117/12.940158; https://doi.org/10.1117/12.940158