STABLE VISIBLE PHOTOLUMINESCENCE AND ELECTROLUMINESCENCE FROM NANOCRYSTALLINE SILICON THIN-FILMS FABRICATED ON THIN SIO2 LAYERS BY LOW-PRESSURE CHEMICAL-VAPOR-DEPOSITION

Nanocrystalline silicon thin films were deposited on thin SiO2 layers by low pressure chemical vapour deposition (LPCVD) at temperatures bet ween 580 and 610 degrees C. The layer thickness was between 15 and 30 nm. The silicon dioxide layer of thickness between 5 and 20 nm was the rmally grown on silicon by high temperature thermal oxidation. Photolu minescence (PL) spectra excited by the 488 nm argon ion laser line sho wed two different emission bands, one present in all luminescent sampl es and centered between 500 and 600 nm and the other between 700 and 8 00 nm which was obtained only for some samples. Stable electroluminesc ent devices were obtained. their electrical characteristics being domi nated by the presence and quality of the oxide layer. Results on I-V a nd C-V measurements will be reported and device performance will be di scussed.