Investigation for optoelectronic characteristics and imaging performance of InAs quantum dot covered with In0.1Ga0.9As/GaAs multilayer based focal plane array

Tzu-Chiang Chen; Jian-Hao Lai

doi:10.1117/1.3572146

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1 June 2011 Investigation for optoelectronic characteristics and imaging performance of InAs quantum dot covered with In₀_.₁Ga₀_.₉As/GaAs multilayer based focal plane array

Tzu-Chiang Chen, Jian-Hao Lai

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Optical Engineering, 50(6), 061004 (2011). https://doi.org/10.1117/1.3572146

Abstract

We report on a structure prepared by metalorganic chemical vapor deposition and molecular beam epitaxy techniques incorporated with a standard process of compound semiconductor to achieve In0.1Ga0.9As/InAs/In0.1Ga0.9As quantum dot infrared photodetector (QDIP)-based focal plane array. For investigating the mechanism of carrier transport and optoelectronic behavior, the photoresponse spectra and dark current were measured in agreement with the theoretical simulations. Furthermore, a model is proposed with the systematic analyses and explained for designing high-performance QDIPs based on the calculations of thermal activation energy and detectivity. For QDIP photoresponse measurements, the photovoltaic photoresponse is achieved, which can be attributed to the asymmetric morphology of quantum dot epitaxy. With increasing bias, the photoresponse spectra exhibit a redshift due to band bending that generates a thinner triangle barrier which increases the escape possibility of the excited carriers situated at lower excited-state levels. The trapezoid-edged scheme enhances infrared coupling and increases the photoresponse intensity. A single-sided gradient AlxGa1-xAs (x = 0.25→0) barrier can suppress the dark-current under bias efficiently. The infrared imaging performance of InGaAs QDIP based on 320×256 FPA is also demonstrated in this paper.

©(2011) Society of Photo-Optical Instrumentation Engineers (SPIE)

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Tzu-Chiang Chen and Jian-Hao Lai "Investigation for optoelectronic characteristics and imaging performance of InAs quantum dot covered with In₀_.₁Ga₀_.₉As/GaAs multilayer based focal plane array," Optical Engineering 50(6), 061004 (1 June 2011). https://doi.org/10.1117/1.3572146

Published: 1 June 2011

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