Title: Non-radiative recombination at dislocations in InAs quantum dots grown on silicon

Abstract

We study the impact of misfit dislocations on the luminescence from InAs quantum dots (QDs) grown on Si substrates. Electron channeling contrast imaging is used together with cathodoluminescence mapping to locate misfit dislocations and characterize the resulting nonradiative recombination of carriers via near-infrared light emission profiles. With a 5 kV electron beam probe, the dark line defect width due to a typical misfit dislocation in a shallow QD active layer is found to be approximately 1 μm, with a 40%–50% peak emission intensity loss at room temperature. Importantly, we find that at cryogenic temperatures, the dislocations affect the QD ground state and the first excited state emission significantly less than the second excited state emission. At the same time, the dark line defect width, which partially relates to carrier diffusion in the system, is relatively constant across the temperature range of 10 K–300 K. Our results suggest that carrier dynamics in the QD wetting layer control emission intensity loss at dislocations, and that these defects reduce luminescence only at those temperatures where the probability of carriers thermalizing from the dots into the wetting layer becomes significant. We discuss the implications of these findings toward growing dislocation-tolerant, reliable quantum dot lasersmore » on silicon.« less

Authors:

Selvidge, Jennifer ^[1]; Norman, Justin ^[1]; Salmon, Michael E. ^[2]; Hughes, Eamonn T.  ^[1];

• Search DOE PAGES for author "Hughes, Eamonn T."
• Search DOE PAGES for ORCID "0000-0003-2428-6923"
• Search orcid.org for ORCID "0000-0003-2428-6923"

Bowers, John E. ^[3]; Herrick, Robert ^[4]; Mukherjee, Kunal  ^[1]

• Search DOE PAGES for author "Mukherjee, Kunal"
• Search DOE PAGES for ORCID "0000-0002-2796-856X"
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+ Show Author Affiliations

1. Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, USA
2. EAG Laboratories–Eurofins Materials Science, 628 Hutton St., Suite 103, Raleigh, North Carolina 27606, USA
3. Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, USA; Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, California 93106, USA
4. Intel Corporation, Santa Clara, California 95054, USA

Publication Date:

2019-09-23

Research Org.:

Columbia Univ., New York, NY (United States)

Sponsoring Org.:

USDOE Advanced Research Projects Agency - Energy (ARPA-E)

OSTI Identifier:

1613736

Alternate Identifier(s):

OSTI ID: 1566273

Grant/Contract Number:  

AR0000843

Resource Type:

Accepted Manuscript

Journal Name:

Applied Physics Letters

Additional Journal Information:

Journal Volume: 115; Journal Issue: 13; Journal ID: ISSN 0003-6951

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Physics; Emission spectroscopy; Quantum dots; Luminescence; Electron beams; Lasers; Crystallographic defects; Epitaxy