Wavelength-Tunable InGaAs-Capped Quantum-Dot Infrared Photodetectors

Author

Lin, Wei-Hsun ; Tseng, Chi-Che ; Chao, Kuang-Ping ; Mai, Shu-Cheng ; Lin, Shih-Yen ; Wu, Meng-Chyi

Author_Institution

Inst. of Electron. Eng., Nat. Tsing Hua Univ., Hsinchu, Taiwan

Volume

22

Issue

4

fYear

2010

Firstpage

227

Lastpage

229

Abstract

Quantum-dot infrared photodetectors (QDIPs) with InGaAs capping layers are investigated. Compared with the standard QDIP with 2.5-mono-layer (ML) InAs QDs, the detection wavelength is shifted from 6 to 7.9 ??m for an 8-nm InGaAs-capped QDIP. By decreasing the QD coverage from 2.5 to 2.0 ML, an even longer detection wavelength 10.4 ??m is observed, which is attributed to the higher energy levels of the QD excited states resulted from the smaller QDs. By further increasing the capping layer thickness to 12 nm, longer detection wavelengths with broad response 10-18 ??m is observed for the InGaAs-capped QDIP.

Keywords

III-V semiconductors; excited states; gallium arsenide; indium compounds; infrared detectors; optical tuning; photodetectors; semiconductor quantum dots; InGaAs; capping layers; detection wavelength shift; excited states; quantum-dot infrared photodetectors; size 12 nm; size 8 nm; wavelength 10 mum to 18 mum; wavelength 6 mum to 7.9 mum; wavelength-tunable photodetectors; Quantum-dot infrared photodetectors (QDIPs);

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2009.2037727

Filename

5373933