Analysis of time-of-flight transient photocurrent in organic semiconductors with coplanar-blocking-electrodes configuration

Time-of-flight transient photocurrent in organic semiconductors with coplanar-blocking-electrodes configuration has been numerically analyzed. Time-of-flight measurements for such a sample configuration enable us to determine the drift mobilities of organic semiconducting materials applicable to organic field effect transistors. It is shown that the charge-carrier transit time can be determined in both non-dispersive and dispersive transport under the condition that the charge-carrier transit time is much shorter than the monomolecular and bimolecular recombination lifetimes. It is also shown that the localized-state distributions can be determined from the analysis of the transient photocurrent.