15 June 2022 Hot-carrier dynamics and transport in III–V heterostructures for photovoltaic applications
Herath P. Piyathilaka, Rishmali Sooriyagoda, Vincent R. Whiteside, Tetsuya D. Mishima, Michael B. Santos, Ian R. Sellers, Alan D. Bristow
Author Affiliations +
Abstract

Type-II multiple quantum well superlattices based on InAs/AlAsSb are investigated for ground- and excited-state charge carrier transport and excited-state charge carrier dynamics. It is found that ground-state transport matches well to impurity and optical phonon interactions, while the excited-state transport shows increased terahertz photoconductivity for the correct excitation conditions that have previously been linked to a metastability in the early time response after photoexcitation. This regime also shows a reduction in carrier mobility, which is also expected to be due to ambipolar diffusion and increased carrier–carrier scattering. Overall, carrier excited-state dynamics confirm the metastability in early time response and are related to strong Auger scattering. For increased excitation intensities, the Auger-scattering rate increases to obtain a lower carrier density more rapidly. The result is a stronger scattering of carriers energetically deeper into their respective bands, where they exhibit a much slower carrier recombination rate and can maintain their relative temperature as a result of a phonon bottleneck that forces reabsorption of optical phonons. In addition to a previously reported phonon bottleneck, the carrier dynamics offer potential pathways to stabilize hot carriers with further bandgap engineering.

© 2022 Society of Photo-Optical Instrumentation Engineers (SPIE) 1947-7988/2022/$28.00 © 2022 SPIE
Herath P. Piyathilaka, Rishmali Sooriyagoda, Vincent R. Whiteside, Tetsuya D. Mishima, Michael B. Santos, Ian R. Sellers, and Alan D. Bristow "Hot-carrier dynamics and transport in III–V heterostructures for photovoltaic applications," Journal of Photonics for Energy 12(3), 032209 (15 June 2022). https://doi.org/10.1117/1.JPE.12.032209
Received: 1 March 2022; Accepted: 24 May 2022; Published: 15 June 2022
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Cited by 2 scholarly publications.
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KEYWORDS
Scattering

Terahertz radiation

Phonons

Heterojunctions

Photovoltaics

Solar energy

Carrier dynamics

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