DETERMINATION OF RECOMBINATION AND PHOTOGENERATION PARAMETERS OF A-SI-H USING PHOTOCONDUCTIVITY MEASUREMENTS

The non-linear dependence of photoconductivity (PC) on wavelength and intensity of illumination was used to evaluate the lifetime and quantu m efficiency coefficient of carrier photogeneration in RF sputtered th in films of a-Si:H. The change of spatial distribution of radiation in tensity over the sample thickness with the change of photon energy has been taken into account. Due to this, for the photon energies greater than the semiconductor energy gap, the decay of PC with an increase o f absorption coefficient of radiation could be described using only on e recombination parameter: the lifetime factor proportional to carrier lifetime. The comparison of the values of absorption coefficient obta ined from the measurements of optical transmittance, CPM and the quant um efficiency coefficient is presented. The determination of carrier l ifetime as a function of energy of photons that generate the free carr iers is discussed.