ELECTROLUMINESCENCE FROM ALUMINUM-POROUS SILICON REVERSE-BIASED SCHOTTKY DIODES FORMED ON THE BASE OF HIGHLY DOPED N-TYPE POLYSILICON

The fabrication and the properties of light-emitting aluminum-porous s ilicon Schottky diodes, formed on the base of highly doped n-type poly silicon are presented. The polysilicon layer was formed on a crystalli ne silicon substrate by low-pressure chemical vapour deposition. Highl y doped n(+)-poly-Si was then formed by phosphorous thermal diffusion. On this material the porous layer was obtained by electrochemical ano dization using process parameters between electropolishing and pore fo rmation regimes. The structure of the formed layer was investigated us ing the transmission electron microscopy technique. Photoluminescence spectra obtained after anodization are reported. The aluminum electrod es (pads) were obtained by standard photolithography and subsequent el ectrochemical aluminum anodization process. Electroluminescence (EL) w as observed in reverse biased junctions. EL emission spectrum was broa d and covered the whole visible range with a maximum at 770-800 nm. Cu rrent-voltage characteristics were determined at different temperature s. The optical and electrical characteristics of the developed light e mitting diodes are promising for display device applications.