Lifetime and recombination kinetics in a-Se thin films

A Comparison of DC and Modulated Photocurrent in Chalcogenide Glasses

“…It is suggested that υ = 1 corresponds to monomolecular recombination and υ = 0.5 to bimolecular recombination. Although, in the case of continuous distribution of traps the value of υ may be anywhere between 0.5 and 1.0 depending on the light intensity and temperature range [15].…”

“…The DC and modulated photocurrent measurements have been widely used for understanding the defect states in the chalcogenide thin films. Recombination process is a key point when describing carrier transport kinetics in such films because it strongly affects the photoresponse of these films at all levels of external excitation [15]. The applied voltage and modulation frequency effects on exponent υ in the power-law relationship I ∼ G υ between generation rate and photocurrent give valuable informations about recombination kinetics and distribution of localized states in the band gap [16].…”

Charge carrier lifetime in boron carbide thin films

“…It should be noted that the measured carrier lifetime in B 4 C film is much longer than that in diamond-like carbon films ͑0.08 ms͒, 9 a-Si:H films ͑ϳ0.1 s͒, 10 and a-Se thin film ͑11.3 s͒. 11 The longer carrier lifetime could be attributed to the unique structural unit ͑icosahedron͒ and the three-center twoelectron bond ͑the electron-deficient bond͒ in amorphous B 4 C films, 12 because the self-induced distortion of the icosahedron via bipolaronic conduction could extend the carrier lifetime. 13 As shown in Table I, besides the laser intensity and the electric field, the carrier lifetime is also affected by the deposition temperature.…”