Steady-state photoconductivity in amorphous semiconductors containing correlated defects

Defect levels in the band gap of amorphous selenium

“…However, subsequent attempts at confirming and expanding on the post-transit analysis results were only partially successful [9]. The thermally accessible levels of the negative-U defects are also instrumental in carrier recombination in chalcogenide semiconductors [10], such that their energy positions in the gap can be derived from the temperature dependence of steady-state photocurrent measurements [11,12]. Following the successful use of this method for several arsenic chalcogenides [13], Qamhieh et al [14] made use of it to pin down the corresponding energy levels in a-Se.…”

Characterization of the interface properties in a-Si : H/c-Si heterostructures by photoluminescence

“…While the higher PL yield after ZnO deposition is solely related to a higher excitation flux, the deposition of Al was shown to result in a higher quasi-Fermi level splitting with improved back-interface properties. The statistics of the interface defects is taken to follow the well-established statistics developed for dangling bonds in a-Si:H which takes into account the three charge states positive, neutral and negative [15,16]. Thus, the defect density at an energy (E) is the sum of the densities in the different charge densities can be derived [15,16].…”

“…The statistics of the interface defects is taken to follow the well-established statistics developed for dangling bonds in a-Si:H which takes into account the three charge states positive, neutral and negative [15,16]. Thus, the defect density at an energy (E) is the sum of the densities in the different charge densities can be derived [15,16]. …”

“…The nature of the interface defect was taken as that of a dangling bond with its three possible charge states and corresponding densities of positive (D+), neutral (D0) and negative (D−) defects. The statistics in terms of a modified ShockleyRead-Hall approach to take account of the double-occupancy and correlation energy between the D+/0 and D0/− transitions was applied [15,16]. No approximations limiting the transitions to capture processes as in [17] have been introduced.…”

Electrical properties of a-Se85−xTe15Snx thin films

“…In chalcogenide glasses, it is assumed that the localized states in the mobility gap are the D + and D À states and that no other levels are significant [1,2]. So, these measurements in chalcogenide glasses may be helpful in understanding the recombination mechanisms, which in turn give information regarding the localized states present in the mobility gap of these materials.…”