US Patent:
20110284756, Nov 24, 2011
Inventors:
Laddawan R. Miko - Lanham MD, US
David E. Franz - Pasadena MD, US
Carl M. Stahle - Severna Park MD, US
Bing Guan - Bowie MD, US
Diane E. Pugel - College Park MD, US
Shahid Aslam - Washington DC, US
International Classification:
G01J 1/42
H01L 27/146
US Classification:
250372, 257440, 257E27134
Abstract:
The invention concerns a single detector with two designable wavelengths and bandwidths for ultraviolet detection based on n/n-GaN and AlGaN structures grown over sapphire substrates. The detector has several layers grown over a sapphire substrates, including a buffer layer comprising AlN; a first band-edge comprising AlGaN; a second band-edge comprising AlGaN; a third band-edge comprising AlGaN. The detector also has ohmic contacts formed on the AlGaN band-edge. A bias voltage is applied to the detector through the ohmic contacts so as to select a range of wavelengths in the UV region of interest.