Relation Between Thermoluminescence and Charge Transport in Polysilylenes

The low-temperature thermally stimulated luminescence (TSL) has been applied for probing the energetic disorder of localized states in poly(methyl-phenylsilylene) (PMPSi). Interpretation of TSL as associated with charge carrier thermal release from intrinsic tail states and based on the Gaussian disorder model is suggested. The analysis the shape of the high-temperature wing of the TSL peak yields the half-width of the density of states (DOS) profile that agrees with energetic disorder parameter determined from the post-transient part of the transient photocurrent. The activation energy in TSL peak maximum is in accord with predictions of the theory for non-activated energetic relaxation of charge-carriers within a manifold of localized states and, therefore, no special features of the DOS in the gap are necessary for the explanation of the existence of the TSL peak The effect of polar additives as dinitrobenzenes is explained in terms of dipolar disorder model.