Optical Studies of Electric-Field-Induced Electron and Hole Transient Transports and Optical Phonon Instability in Semiconductor Nanostructures

In this chapter the use of picosecond/subpicosecond time-resolved/transient Raman spectroscopy to study electric-field-induced transient carrier transport and longitudinal optical phonons in semiconductor nanostructures is demonstrated. The important physics behind transient carrier transport in nanostructure semiconductors is revealed. Experimental results on electron-velocity overshoot in a GaAs-based p--i--n nanostructure are presented and discussed. In addition, electron ballistic transport in an InP-based p--i--n nanostructure and electron- as well as hole-velocity overshoots in an Al\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{0.3}$$\end{document}Ga\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{0.7}$$\end{document}As-based p--i--n nanostructure are demonstrated and discussed. Cerenkov generation of optical phonons by drifting electrons in GaAs-based p--i--n nanostructure is reported. Finally, some future challenging experiments related to these novel transient carrier transport phenomena are addressed.