Ap. Tyutnev et al., METHODOLOGICAL PROBLEMS OF DETERMINING THE MOBILITY OF EXCESS CHARGE-CARRIERS IN MOLECULARLY DOPED POLYMERS, Vysokomolekularnye soedinenia. Seria A, 40(6), 1998, pp. 1062-1068
The room-temperature mobility of holes in a molecularly doped polymer
(polycarbonate containing 30 wt% of hydrazone) was studied by methods
of nonstationary radiation-induced electric conductivity, time-of-flig
ht measurements, and pulsed monopolar carrier injection. It was establ
ished that the hole transport in the polymer system studied during sho
rt periods of time (hundreds of microseconds or a few milliseconds) af
ter the pulsed generation of carriers occurs in a dispersion regime (w
ith a dispersion parameter of similar to 0.4). Then the effective mobi
lity attains a plateau, and the transport regime changes from dispersi
on to Gaussian. The time-of-flight and stationary mobility values are
strongly dependent on the strength of applied electric field. All thre
e methods are virtually equally informative in studying the dispersion
branch of the time variation of the effective mobility, while the Gau
ssian transport regime is more conveniently studied by the time-of-fli
ght technique.