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Proceedings Paper

Ultraviolet-to-infrared dual-band detectors based on quantum dot and heterojunction structures
Author(s): A. G. Unil Perera
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Paper Abstract

Tunneling quantum dot photodetector (T-QDIP) structures designed for multi-band infrared and heterojunction detectors for ultraviolet (UV) to infrared (IR) radiation detection are presented. In T-QDIPs, photoabsorption takes place in InGaAs QDs due to intersubband transitions of carriers. Photoexcited carriers are selectively collected through resonant tunneling, while the dark current is blocked by AlGaAs/InGaAs tunneling barriers. This approach to block dark current without reducing photocurrent was observed in a detector responding at ~ 6 and ~ 17 μm up to 300 K. In addition, UV/IR dual-band detectors were developed based on GaN/AlGaN Heterojunction Interfacial Workfunction Internal Photoemission (HEIWIP) structures. A typical HEIWIP detector structure consists of a single (or series of) doped emitter(s) followed by an undoped barrier(s) between two highly doped contact layers. Reported UV/IR structures use n-doped GaN emitters and AlxGa1-xN barriers. The UV response is due to interband (valence-to-conduction) transitions in the undoped AlGaN barrier, while the IR response arises from intraband transitions in the n-doped GaN emitter. Preliminary detectors were successfully demonstrated with a 360 nm threshold UV response up to 300 K and 8-14 μm IR response up to 80 K.

Paper Details

Date Published: 11 March 2008
PDF: 6 pages
Proc. SPIE 6984, Sixth International Conference on Thin Film Physics and Applications, 698432 (11 March 2008); doi: 10.1117/12.792385
Show Author Affiliations
A. G. Unil Perera, Georgia State Univ. (United States)


Published in SPIE Proceedings Vol. 6984:
Sixth International Conference on Thin Film Physics and Applications

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