Enhanced Photoluminescence of 1.3 μm InAs Quantum Dots Grown on Ultrathin GaAs Buffer/Si Templates by Suppressing Interfacial Defect Emission

Yeonhwa Kim; Rafael Jumar Chu; Geunhwan Ryu; Seungwan Woo; Quang Nhat Dang Lung; Dae-Hwan Ahn; Jae-Hoon Han; Won Jun Choi; Daehwan Jung

doi:10.1021/acsami.2c14492

Enhanced Photoluminescence of 1.3 μm InAs Quantum Dots Grown on Ultrathin GaAs Buffer/Si Templates by Suppressing Interfacial Defect Emission

ACS Appl Mater Interfaces. 2022 Oct 5;14(39):45051-45058. doi: 10.1021/acsami.2c14492. Epub 2022 Sep 26.

Authors

Yeonhwa Kim^{1

2}, Rafael Jumar Chu^{1

2}, Geunhwan Ryu¹, Seungwan Woo^{1

3}, Quang Nhat Dang Lung^{1

2}, Dae-Hwan Ahn¹, Jae-Hoon Han¹, Won Jun Choi¹, Daehwan Jung^{1

2}

Affiliations

¹ Center for Opto-electronic Materials and Devices, Korea Institute of Science and Technology, Seoul 02792, South Korea.
² Division of Nano & Information Technology, University of Science and Technology, Seoul 02792, South Korea.
³ Department of Materials Science and Engineering, Korea University, Seoul 02481, South Korea.

PMID: 36162121
DOI: 10.1021/acsami.2c14492

Abstract

We report on the photoluminescence enhancement of 1.3 μm InAs quantum dots (QDs) epitaxially grown on an ultrathin 250 nm GaAs buffer on a Si substrate. Decreasing the GaAs buffer thickness from 1000 to 250 nm was found to not only increase the coalesced QD density from 6.5 × 10⁸ to 1.9 × 10⁹ cm^-2 but also decrease the QD photoluminescence emission intensity dramatically. Inserting an Al_0.4Ga_0.6As potential barrier layer maintained strong photoluminescence from the QDs by effectively suppressing carrier leakage to the GaAs/Si interfacial region even when the GaAs buffer was thinned to 250 nm. We then fabricated a light-emitting diode using the ultrathin 250 nm GaAs buffer on Si and confirmed strong electroluminescence peaking at 1.28 μm without interfacial defect emission at room temperature. We believe that this work is promising for monolithically integrated evanescent Si lasers using InAs/GaAs QDs.

Keywords: defect; electroluminescence; epitaxy; photoluminescence; quantum dot; silicon photonics.