PHOTOCONDUCTIVITY DURING 30 NS LASER-PULSES IN A-SI-H

The photoconductivity, sigma(p)(t), of intrinsic and compensated hydro genated amorphous silicon (a-Si:H) was measured at room temperature wi th nanosecond time resolution during 30 ns long laser pulses of 650 nm wavelength and pulse energies, P, between 35 mJ/cm(2) and 2 mu J/cm(2 ). For larger P the response time of sigma(p) is faster than 1 ns and sigma(p) = cP(1/2) with the same c value for ail samples studied, inde pendent of defect concentration, N-D. Deviations from this bimolecular recombination law begin when the total steady state photocarrier conc entration becomes comparable to or less than N-D.