Title :
Characteristics of a multicolor InGaAs-GaAs quantum-dot infrared photodetector
Author :
Chakrabarti, S. ; Su, X.H. ; Bhattacharya, Pallab ; Ariyawansa, G. ; Perera, A.G.U.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Univ. of Michigan, Ann Arbor, MI, USA
Abstract :
A three-color quantum-dot infrared photodetector has been fabricated and characterized. The active absorption region consists of undoped In/sub 0.4/Ga/sub 0.6/As quantum dots separated by GaAs barriers. Intersublevel transitions of electrons in the quantum dots results in absorption peaks at /spl sim/3.5, 7.5, and 22 μm. The devices were characterized at 80 K and 120 K. The dark current density is 10/sup -6/ A/cm2 at 120 K for an applied bias of 1 V. The responsivity and specific detectivity D/sup */ are 0.07 A/W and 4.8×10/sup 10/ cm/spl middot/Hz12//W for the 7.5-μm response at 80 K for an applied bias of 3 V.
Keywords :
III-V semiconductors; current density; gallium arsenide; indium compounds; infrared detectors; photodetectors; semiconductor quantum dots; 1 V; 120 K; 3 V; 80 K; InGaAs-GaAs; absorption peaks; dark current density; intersublevel transitions; multicolor InGaAs-GaAs quantum-dot infrared photodetector; responsivity; specific detectivity; Dark current; Density measurement; Electromagnetic wave absorption; Electrons; Extraterrestrial measurements; Gallium arsenide; Infrared detectors; Photodetectors; Quantum dots; Temperature; Dark current; InAs–GaAs; detectivity; infrared detector; quantum dots; responsivity;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2004.838295
