Investigation of carrier capture dynamics in InAs/GaAs single-layer quantum dots using terahertz time-resolved spectroscopy

Authors

Vince Paul Juguilon ⋅ PH National Institute of Physics, University of the Philippines Diliman
Deborah Anne Lumantas-Colades ⋅ PH National Institute of Physics, University of the Philippines Diliman
Neil Irvin Cabello ⋅ PH National Institute of Physics, University of the Philippines Diliman
Alexander De Los Reyes ⋅ PH National Institute of Physics, University of the Philippines Diliman
Inhee Maeng ⋅ KR YUHS-KRIBB Medical Convergence Research Institute, Yonsei University College of Medicine, Korea
Chul Kang ⋅ KR Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Korea
Chul-Sik Kee ⋅ KR Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Korea
Elmer Estacio ⋅ PH National Institute of Physics, University of the Philippines Diliman

Abstract

We observe carrier capture saturation at high excitation fluence in InAs/GaAs single-layer quantum dots using an optical pump-terahertz probe experiment conducted at room-temperature. Results show that carrier lifetime using a 0.4 mW optical pump was relatively constant at 500 ps, whereas the sample exited by 7.0 mW optical pump has lifetime of 3.7 ns immediately upon photoexcitation. Carrier lifetimes for all optical pump powers considered were observed to decrease and converge to around 500 ps after sufficient time. Calculations show that the 0.4 mW pump has photon density of 9.60 × 1010 photons/cm2 with a corresponding carrier density of 3 to 4 photoexcited carriers per dot. Meanwhile, the 7.0 mW pump has photon density of 1.68×10¹² photons/cm² with carrier density of 64 to 65 carriers per dot. This could imply that any increase in the excitation fluence may result to the filling of QD states, leading to an increase in the carrier lifetime of the sample.

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Issue

2022: Proceedings of the 40th Samahang Pisika ng Pilipinas Physics Conference

Article ID

SPP-2022-1F-05

Section

Optics and Photonics

Published

2022-10-03

How to Cite

[1]

VP Juguilon, DA Lumantas-Colades, NI Cabello, A De Los Reyes, I Maeng, C Kang, C-S Kee, and E Estacio, Investigation of carrier capture dynamics in InAs/GaAs single-layer quantum dots using terahertz time-resolved spectroscopy, Proceedings of the Samahang Pisika ng Pilipinas 40, SPP-2022-1F-05 (2022). URL: https://proceedings.spp-online.org/article/view/SPP-2022-1F-05.