Lifetime and recombination kinetics in a-Se thin films

摘要: Abstract Modulated photoconductivity measurements in amorphous selenium (a-Se) thin films were carried out. Especially, photocarrier lifetime as a function of applied electric field (d.c.) and temperature was determined by using the quadrature frequency-resolved spectroscopy (QFRS) method. At low temperature, two different carrier channels observed. However, only one channel dominated at room (297 K). The dependence photocurrent (FRPC) investigated under fields. high temperatures, small independent activation energy value 147 ± 35 meV determined, which hole transport is controlled valence band-tail states. exponent ν power-law relationship ( I ph ∝ G ) between generating flux obtained fields excitation wavelengths. increases very little with decreasing shows stronger on dependences wavelengths also directly measured. non-ohmic behaviour observed We explained it frame traditional models.