Non-equilibrium Green's function calculation of AlGaAs-well-based and GaSb-based terahertz quantum cascade laser structures

Journal Article · Mon Mar 16 00:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4916235· OSTI ID:22395746

Hosako, I. ^[1]

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1. National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo 184-8795 (Japan)

We investigate the performance of terahertz quantum cascade lasers (THz-QCLs) based on Al{sub x}Ga{sub 1−x}As/Al{sub y}Ga{sub 1−y}As and GaSb/AlGaSb material systems to realize higher-temperature operation. Calculations with the non-equilibrium Green's function method reveal that the AlGaAs-well-based THz-QCLs do not show improved performance, mainly because of alloy scattering in the ternary compound semiconductor. The GaSb-based THz-QCLs offer clear advantages over GaAs-based THz-QCLs. Weaker longitudinal optical phonon–electron interaction in GaSb produces higher peaks in the spectral functions of the lasing levels, which enables more electrons to be accumulated in the upper lasing level.

• OSTI ID: 22395746
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 11 Vol. 106; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTROSCOPY
ALUMINIUM ARSENIDES
ELECTRON-PHONON COUPLING
ELECTRONS
EQUILIBRIUM
GALLIUM ANTIMONIDES
GALLIUM ARSENIDES
GREEN FUNCTION
OPERATION
PERFORMANCE
PHONONS
SCATTERING
SEMICONDUCTOR MATERIALS
SPECTRAL FUNCTIONS
X-RAY SPECTROSCOPY