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Correlation between Optical Localization-State and Electrical Deep-Level State in In 0.52Al 0.48As/In 0.53Ga 0.47As Quantum Well Structure. NANOMATERIALS 2021; 11:nano11030585. [PMID: 33652753 PMCID: PMC7996928 DOI: 10.3390/nano11030585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 11/23/2022]
Abstract
The peculiar correlationship between the optical localization-state and the electrical deep-level defect-state was observed in the In0.52Al0.48As/In0.53Ga0.47As quantum well structure that comprises two quantum-confined electron-states and two hole-subbands. The sample clearly exhibited the Fermi edge singularity (FES) peak in its photoluminescence spectrum at 10–300 K; and the FES peak was analyzed in terms of the phenomenological line shape model with key physical parameters such as the Fermi energy, the hole localization energy, and the band-to-band transition amplitude. Through the comprehensive studies on both the theoretical calculation and the experimental evaluation of the energy band profile, we found out that the localized state, which is separated above by ~0.07 eV from the first excited hole-subband, corresponds to the deep-level state, residing at the position of ~0.75 eV far below the conduction band (i.e., near the valence band edge).
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Kainz MA, Semtsiv MP, Tsianos G, Kurlov S, Masselink WT, Schönhuber S, Detz H, Schrenk W, Unterrainer K, Strasser G, Andrews AM. Thermoelectric-cooled terahertz quantum cascade lasers. OPTICS EXPRESS 2019; 27:20688-20693. [PMID: 31510157 DOI: 10.1364/oe.27.020688] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 06/20/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate the first lasing emission of a thermo-electrically cooled terahertz quantum cascade laser (THz QCL). A high temperature three-well THz QCL emitting at 3.8 THz is mounted to a novel five-stage thermoelectric cooler reaching a temperature difference of ΔT = 124 K. The temperature and time-dependent laser performance is investigated and shows a peak pulse power of 4.4 mW and a peak average output power of 100 μW for steady-state operation.
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Kainz MA, Schönhuber S, Andrews AM, Detz H, Limbacher B, Strasser G, Unterrainer K. Barrier Height Tuning of Terahertz Quantum Cascade Lasers for High-Temperature Operation. ACS PHOTONICS 2018; 5:4687-4693. [PMID: 31037249 PMCID: PMC6482977 DOI: 10.1021/acsphotonics.8b01280] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Indexed: 06/09/2023]
Abstract
Terahertz quantum cascade lasers (QCLs) are excellent coherent light sources, but are still limited to an operating temperature below 200 K. To tackle this, we analyze the influence of the barrier height for the identical three-well terahertz QCL layer sequence by comparing different aluminum concentrations (x = 0.12-0.24) in the GaAs/Al x Ga1-x As material system, and then we present an optimized structure based on these findings. Electron injection and extraction mechanisms as well as LO-phonon depopulation processes play crucial roles in the efficient operation of these lasers and are investigated in this study. Experimental results of the barrier height study show the highest operating temperature of 186.5 K for the structure with 21% aluminum barriers, with a record k B T max/ℏω value of 1.36 for a three-well active region design. An optimized heterostructure with 21% aluminum concentration and reduced cavity waveguide losses is designed and enables a record operating temperature of 196 K for a 3.8 THz QCL.
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Affiliation(s)
- Martin Alexander Kainz
- Photonics
Institut, TU Wien, 1040 Vienna, Austria
- Center
for Micro- and Nanostructures, TU Wien, 1040 Vienna, Austria
| | - Sebastian Schönhuber
- Photonics
Institut, TU Wien, 1040 Vienna, Austria
- Center
for Micro- and Nanostructures, TU Wien, 1040 Vienna, Austria
| | - Aaron Maxwell Andrews
- Center
for Micro- and Nanostructures, TU Wien, 1040 Vienna, Austria
- Institute
of Solid State Electronics, TU Wien, 1040 Vienna, Austria
| | - Hermann Detz
- Center
for Micro- and Nanostructures, TU Wien, 1040 Vienna, Austria
- Central
European Institute of Technology, Brno University
of Technology, 61200 Brno, Czech Republic
| | - Benedikt Limbacher
- Photonics
Institut, TU Wien, 1040 Vienna, Austria
- Center
for Micro- and Nanostructures, TU Wien, 1040 Vienna, Austria
| | - Gottfried Strasser
- Center
for Micro- and Nanostructures, TU Wien, 1040 Vienna, Austria
- Institute
of Solid State Electronics, TU Wien, 1040 Vienna, Austria
| | - Karl Unterrainer
- Photonics
Institut, TU Wien, 1040 Vienna, Austria
- Center
for Micro- and Nanostructures, TU Wien, 1040 Vienna, Austria
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