Photo and electroluminescence from PECVD grown a-Si:H/SiO2 multilayers

Abstract Multilayers (ML) of a-Si:H/SiO2 have been grown using plasma enhanced chemical vapor deposition. Room-temperature photoluminescence (PL) and electroluminescence (EL) in the range 1.35–1.8 eV has been observed in as-deposited and annealed samples. A noticeable redshift of the PL peak has been detected by increasing the a-Si:H layer thickness in the range 0.7–2.1 nm, as well as the annealing temperature (700–1200°C). The strong correlation between PL and EL spectra indicates that light emission from a-Si:H/SiO2 ML can be attributed to the same luminescence centers in Si layers and nanoclusters. The luminescence mechanism can be interpreted in terms of quantum and spatial confinement of carriers.