Carrier mobility in a polar semiconductor measured by an optical pump-probe technique

Muneaki Hase
2009 Applied Physics Letters  
Ultrafast dephasing of the plasmonlike longitudinal optical phonon-plasmon coupled ͑LOPC͒ mode in highly doped n-GaAs has been investigated by using a femtosecond optical pump-probe technique with 40 THz bandwidth as a function of photodoping levels. The direct measurement of plasmon damping with the help of a wavelet analysis enables us to extract carrier ͑electron͒ mobility, which decreases with increasing the photodoping levels. It is found that the mobility is suppressed at high photodoping
more » ... at high photodoping levels due to electron-hole scattering, while it is enhanced near a critical density, being plausibly attributed to the strong coherent coupling of the LO phonon with the plasmon.
doi:10.1063/1.3103275 fatcat:2bx4k2gi3bh4heml4lv4uei6ty