Short-period scattering-assisted terahertz quantum cascade lasers operating at high temperatures

Scientific Reports

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[1] THz Quantum Device Team, RIKEN Center for Advanced Photonics, 519-1399 Aramaki-aza Aoba, Aoba-ku, 980-0845, Sendai, Japan;THz Quantum Device Team, RIKEN Center for Advanced Photonics, 519-1399 Aramaki-aza Aoba, Aoba-ku, 980-0845, Sendai, Japan;0000 0001 2314 964X, grid.41156.37, School of Electronics Science and Engineering, Nanjing University, 163 Xianlin Street, Qixia District, 210046, Nanjing, China;nextnano GmbH, Lichtenbergstr. 8, 85748, Garching bei München, Germany;

DOI  :  10.1038/s41598-019-45957-8

来源: publisher

【 摘 要 】

Operating at high temperatures in the range of thermoelectric coolers is essential for terahertz quantum cascade lasers to real applications. The use of scattering-assisted injection scheme enables an increase in operating temperature. This concept, however, has not been implemented in a short-period structure consisting of two quantum wells. In this work, based on non-equilibrium Green’s function calculations, it emphasizes on the current leakage and parasitic absorption via high-energy states as fundamental limitations in this scheme with short-period. A new design concept employing asymmetric wells composition is proposed to suppress these limitations. A peak gain of 40 cm−1 at 230 K is predicted in the GaAs/AlGaAs semiconductor material system with an emission frequency of 3.5 THz.

【 授权许可】

CC BY