Open AccessTensile-strained Ge/SiGe quantum-well photodetectors on silicon substrates with extended infrared response
Author(s) -
GuoEn Chang,
Shaowei Chen,
Hung-Hsiang Cheng
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.017562
Subject(s) - photodetector , materials science , optoelectronics , silicon , infrared , ultimate tensile strength , quantum well , semiconductor , band gap , germanium , strained silicon , stack (abstract data type) , optics , composite material , crystalline silicon , physics , amorphous silicon , laser , computer science , programming language
We report on tensile-strained Ge/Si 0.11 Ge 0.89 quantum-well (QW) metal-semiconductor-metal (MSM) photodetectors on Si substrates. A tensile strain of 0.21% is introduced into the Ge wells by growing the QW stack on in-situ annealed Ge-on-Si virtual substrates (VS). The optical characterization of Ge/Si 0.11 Ge 0.89 QW MSM photodetectors indicates that the optical response increases to a wavelength of 1.5 μm or higher owing to the strain-induced direct bandgap shrinkage. Analysis of the band structure by using a k · p model suggests that by optimizing the tensile strain and Ge well width, tensile-strained Ge/SiGe QW photodetectors can be designed to cover the telecommunication C-band and beyond for optical telecommunications and on-chip interconnection.