Carrier dynamics and conductivity of SnO2 nanowires investigated by time-resolved terahertz spectroscopy

THz spectroscopy has been applied to investigate the photo-induced and intrinsic conductivity in SnO2 nanowires using the Drude-Smith model. The refractive index of the nanowires was found to decrease from 2.4 to 2.1 with increasing THz frequency and the dc mobility of the non-excited nanowires was determined to be 72 +/- 10 cm(2)/Vs. Measurements reveal that scattering times are carrier density dependent, while a strong suppression of long transport is evident. Intensity-dependent measurements provided an estimate of the Auger coefficient found to be gamma = (7.2 +/- 2.0) x 10(-31) cm(6)/s. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3698097]