Hot electron cooling in InSb probed by ultrafast time-resolved terahertz cyclotron resonance

Article

关键词: TEMPERATURE-DEPENDENCE;    PHOTOEXCITED CARRIERS;    BAND-STRUCTURE;    RELAXATION;    GAAS;    TRANSPORT;    INAS;    GAP;    THERMALIZATION;    DIFFUSION;   

DOI  :  10.1103/PhysRevB.103.245205

来源: SCIE

【 摘 要 】

Measuring terahertz (THz) conductivity on an ultrafast timescale is an excellent way to observe charge-carrier dynamics in semiconductors as a function of time after photoexcitation. However, a conductivity measurement alone cannot separate the effects of charge-carrier recombination from effective mass changes as charges cool and experience different regions of the electronic band structure. Here we present a form of time-resolved magneto-THz spectroscopy that allows us to measure cyclotron effective mass on a picosecond timescale. We demonstrate this technique by observing electron cooling in the technologically significant narrow-bandgap semiconductor indium antimonide. A significant reduction of electron effective mass from 0.032 to 0.017 m(e) is observed in the first 200 ps after injecting hot electrons. The measured electron effective mass in InSb as a function of photoinjected electron density agrees well with conduction band nonparabolicity predictions from ab initio calculations of the quasiparticle band structure.

【 授权许可】

Free