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

Multilayers (ML) of a-Si:II/SiO2 have been grown using plasma enhanced chem ical vapor deposition. Room-temperature photoluminescence (PL) and electrol uminescence (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 detect ed by increasing the a-Si:H layer thickness in the range 0.7-2.1 nm, as wel l as the annealing temperature (700-1200 degreesC). The strong correlation between PL and EL spectra indicates that light emission from a-Si:HISiO2 ML can be attributed to the same luminescence centers in Si layers and nanocl usters. The luminescence mechanism can be interpreted in terms of quantum a nd spatial confinement of carriers. (C) 2001 Elsevier Science B.V. All righ ts reserved.