Cadmium selenide-amorphous hydrogenated silicon heterostructures

Heterojunctions have been fabricated between CdSe films made by vacuum evaporation and amorphous hydrogenated Si films deposited by plasma discharge. With adjusted conditions, junctions of good rectification ratios have been produced (1000:1 at 2 V), although showing significant interface states. The band offsets were determined by an internal photoemission technique as 0.06 eV for the valence bands and 0.02 eV for the conduction bands. A small unoptimised solar cell gave near 7% efficiency.