Dispersiveness of the transient secondary photocurrent in phosphorushyphen;doped hydrogenated amorphous silicon (ahyphen;Si:H) was discussed. Because the recombination kinetics in the system are bimolecular and, as shown previously, the excess electrons are in a quasithermal equilibrium between the conduction band and shallow traps within a very short period of time after pulsed excitation, it has been inferred that the dispersiveness of the transient secondary photocurrent can be attributed to a distribution of recombination coefficients of excess trapped holes. Following this result, the rate equations for representing relaxation processes of excess carriers, including the bimolecular recombination process, were analyzed and the procedure for evaluating the distribution of recombination coefficients of excess trapped holes was derived. The transient secondary photocurrents of phosphorushyphen;dopedahyphen;S:H with different doping levels were analyzed according to the proposed method. Two components were noticed in the spectrum of the distribution of recombination coefficients; the main component was located in the range of 10minus;11ndash;10minus;9cm3thinsp;sminus;1and the additional component was located in the range of 10minus;14ndash;10minus;12cm3thinsp;sminus;1. From the discussion about these results, combined with the results previously obtained, it was concluded that those distributed values of the recombination coefficients were those of the two hole traps in phosphorushyphen;dopedahyphen;Si:H.
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