Adjustable ultraviolet-sensitive detectors based on amorphous silicon

Thin-film detectors made of hydrogenated amorphous silicon (LI-Si:H) and am orphous silicon carbide (a-SiC:H) with adjustable sensitivity in the ultrav iolet (UV) spectrum were developed. Thin PIN diodes deposited on glass subs trates in N-I-P layer sequence with a total thickness of down to 33 nm and a semitransparent Ag front contact were fabricated. The optimized diodes wi th a 10 nm Ag contact exhibit spectral response values above 80 mA/W in the wavelength range from 295 to 395 nm with a maximum of 91 mA/W at 320 nm, F or longer wavelengths, the spectral response drops by 50% at 450 nm. Increa sing the thickness of the Ag front contact leads to a narrowing of the spec tral response at around 320 nm, which allows the adjustment from a broad UV to a selective UV-B-sensitive detector. (C) 2001 American Institute of Phy sics.