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Title: Optimization of barrier layer thickness in MgSe/CdSe quantum wells for intersubband devices in the near infrared region

The authors report the optimization of MgSe barrier thickness in CdSe/MgSe multiple quantum well structures and its effect on structural, optical qualities and intersubband (ISB) transition characteristics. Three samples with the MgSe thicknesses of 2 nm, 3 nm, and 4 nm were grown on InP substrates by molecular beam epitaxy. X-ray diffraction and photoluminescence measurements showed that the thinner the MgSe barrier thickness the better the structural quality. However, ISB absorption was only observed in the sample with a MgSe thickness of 3 nm. Failing to observe ISB absorption in the sample with a thicker MgSe barrier (≥4 nm) is due to the deteriorated material quality while the missing of ISB transition in the sample with thinner barrier (≤2 nm) is due to the tunneling of electrons out of the CdSe wells. The optimized MgSe barrier thickness of around 3 nm is found to be able to suppress the electron tunneling while maintaining a good material quality of the overall structure.
Authors:
;  [1] ;  [2]
  1. Department of Electrical Engineering, The City College of New York, New York 10031 (United States)
  2. Department of Chemistry, The City College of New York, New York, New York 10031 (United States)
Publication Date:
OSTI Identifier:
22492880
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 16; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; CADMIUM SELENIDES; INDIUM PHOSPHIDES; MOLECULAR BEAM EPITAXY; OPTIMIZATION; PHOTOLUMINESCENCE; QUANTUM WELLS; SUBSTRATES; THICKNESS; TUNNEL EFFECT; X-RAY DIFFRACTION