Steady-state photomodulation spectroscopy of a-Si:HI a-SiNx:H multilayer structures

The steady-state photomodulation (PM) spectrum and its temperature dependence were studied in a-Si:H/a-SiNx:H multilayer structures (MLS). We found that the photocarrier properties in MLS with Si sub layer thickness ds < 20 A are dominated by band-tail broadening resulting from increase in disorder. The PM spectrum for MLS with ds > 20 A is mainly due to interfacerelated defects; because of its similarity with the PM spectrum of P-doped a-Si:H we identify the defects as charged dangling bonds