Title :
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
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);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2009.2037727
