학술논문

Enhanced LWIR response of InP/InAsP quantum discs-in-nanowire array photodetectors by photogating and ultra-thin ITO contacts
Document Type
Source
Nanotechnology NanoLund: Centre for Nanoscience. 35(21)
Subject
infrared photodetectors
long-wavelength infrared (LWIR)
nanowire array photodetectors
nanowires
photogating
quantum discs-in-nanowires
ultra-thin ITO contacts
Naturvetenskap
Fysik
Den kondenserade materiens fysik
Natural Sciences
Physical Sciences
Condensed Matter Physics
Language
English
ISSN
0957-4484
Abstract
Here we report on an experimental and theoretical investigation of the long-wavelength infrared (LWIR) photoresponse of photodetectors based on arrays of three million InP nanowires with axially embedded InAsP quantum discs. An ultra-thin top indium tin oxide contact combined with a novel photogating mechanism facilitates an improved LWIR normal incidence sensitivity in contrast to traditional planar quantum well photodetectors. The electronic structure of the quantum discs, including strain and defect-induced photogating effects, and optical transition matrix elements were calculated by an 8-band k·p simulation along with solving drift-diffusion equations to unravel the physics behind the generation of narrow linewidth intersubband signals observed from the quantum discs.