[A-6] III-V Light Sources

[A-6-07] [No Show] Consideration of the interface diffusions for narrow-period terahertz quantum cascade lasers

〇Li WANG¹, Tsung-Tse Lin¹, Thomas Grange², Ke Wang³, Hideki Hirayama¹ (1. RIKEN (Japan), 2. nextnano (Germany), 3. nanjing Univ. (China))

Presentation style: Online

The effects of diffused interface scattering on the transport and the optical gain is still not well shown. In this work, we have determined the interface profiles of GaAs/Al0.3Ga0.7As quantum structures using transmis-sion electron microscopy (TEM). The diffused width is extracted following sigmdial-type functions and then used as basic parameters to estimate the scattering of such a diffused interface based on NEGF method. The optical gain of the 3-level terahertz quantum cascade lasers at 300K is 32% down when such a diffused interface is con-sidered. However, the corresponding scattering is not the reason as its strength is quite small that plays a minor role on the lifetime of states, instead, the shifting of wave-function is original for this change of gain by leading to an obvious misalignment of resonant tunneling for injec-tion.