Share Email Print
cover

Proceedings Paper

Cross-sectional TEM (XTEM) analysis for vertically coupled quaternary In0.21Al0.21Ga0.58As capped InAs/GaAs quantum dot infrared photodetectors
Author(s): Binita Tongbram; Hemant Ghadi; Sourav Adhikary; Arjun Mandal; Subhananda Chakrabarti
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

This paper presents a detailed morphological analysis of vertically strain-coupled InAs quantum dots with a fixed quaternary capping (In0.21Al0.21Ga0.58As) of 3 nm and a GaAs barrier ranging in thicknesses from 9 to 18 nm. The coupled heterostructures were studied using cross-sectional transmission electron microscopy and compared with uncoupled heterostructures with 2-nm quaternary capping and 50-nm GaAs capping thickness. Power-dependent photoluminescence spectra showed that a minimum capping of 9 nm produced a multimodal dot-size distribution. Increasing the capping from 9 to 18 nm reduced the vertical correlation, thus increasing the dot uniformity. Increasing the capping thickness reduced the coupling and increased the dot size. At a maximum capping (18nm) coupled quantum dots exhibit a bimodal dot-size distribution compared to the mono-modal distribution of the uncoupled quantum dots. The coupled samples demonstrated superior optical properties to uncoupled samples.

Paper Details

Date Published: 27 February 2015
PDF: 10 pages
Proc. SPIE 9373, Quantum Dots and Nanostructures: Synthesis, Characterization, and Modeling XII, 93730S (27 February 2015); doi: 10.1117/12.2074835
Show Author Affiliations
Binita Tongbram, Indian Institute of Technology Bombay (India)
Hemant Ghadi, Indian Institute of Technology Bombay (India)
Sourav Adhikary, Indian Institute of Technology Bombay (India)
Arjun Mandal, Indian Institute of Technology Bombay (India)
Subhananda Chakrabarti, Indian Institute of Technology Bombay (India)


Published in SPIE Proceedings Vol. 9373:
Quantum Dots and Nanostructures: Synthesis, Characterization, and Modeling XII
Diana L. Huffaker; Holger Eisele, Editor(s)

© SPIE. Terms of Use
Back to Top