Terahertz quantum well infrared photodetector
Abstract
The quantum well infrared photodetectors work well between about 3 to 30 microns in wavelength, using GaAs/AlGaAs materials. This work reports on an attempt in extending the wavelength coverage into the terahertz frequencies, i.e., into wavelengths longer than 30 microns. (30 microns in wavelength correspond to 10 terahertz in frequency.) A set of three wafers were grown and tested. A device with an aluminum fraction of 5% worked up to about 37 microns. The other two with 3 and 1.5% Al did not show any measurable photoresponse. In all cases, the background-limited infrared performance could not be reached with lowering the operating temperature. The dark current initially decreased with lowering the temperature but stopped in the 10-15 K region. Factors that influence the dark current will be discussed, and areas that can be improved will be pointed out.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARB10002L