Observation of optical phonon instability induced by drifting electrons in semic

2019-12-23 02:06:28

optical semiconductor electrons instability phonons

责任者: Liang, W.;Tsen, K.T.;Sankey, O.F.;Komirenko, S.M.;Kim, K.W.;Kochelap, V.A.;Meng-Chyi Wu;Ho, C.-L.;Wen-Jeng Ho;Morkoc, H. 单位: Dept. of Phys. & Astron., Arizona State Univ., Tempe, AZ, USA 来源出处: Applied Physics Letters(Appl. Phys. Lett. (USA)),2003/03/24,82(12):1968-70 摘要: We have experimentally proven the Cerenkov generation of optical phonons by drifting electrons in a semiconductor. We observe an instability of the polar optical phonons in nanoscale semiconductors that occurs when electrons are accelerated to very high velocities by intense electric fields. The instability is observed when the electron drift velocity is larger than the phase velocity of optical phonons and rather resembles a sonic boom for optical phonons. The effect is demonstrated in p-i-n semiconductor nanostructures by using subpicosecond Raman spectroscopy 关键词: acoustoelectric effects;aluminium compounds;Cherenkov radiation;gallium arsenide;III-V semiconductors;interface phonons;p-n heterojunctions;Raman spectra;optical phonon instability;drifting electrons;Cerenkov generation;polar optical phonons;electron drift velocity;p-i-n semiconductor nanostructures;subpicosecond Raman spectra;AlAs-GaAs-AlAs