Electron-density dependence of longitudinal-optical phonon lifetime in InN studied by subpicosecond time-resolved Raman spectroscopy

摘要

Subpicosecond time- resolved Raman spectroscopy has been used to measure the lifetime of the A(1)( LO) and E-1( LO) phonon modes in InN at T = 10 K for photoexcited electron - hole pair density ranging from 5 x 10(17) to 2 x 10(19) cm(-3). The lifetime has been found to decrease from 2.2 ps at the lowest density to 0.25 ps at the highest density. Our experimental findings demonstrate that the carrier- density dependence of LO phonon lifetime is a universal phenomenon in polar semiconductors.