Complex permittivity analysis revisited: Microwave spectroscopy of organic semiconductors with resonant cavity

摘要

The complex permittivity analysis of microwave dielectric loss spectroscopy has been revisited to deduce the intrinsic values of the mobility of charge carriers injected at the interface between an organic semiconductor and a gate insulator. A perturbation model with a simple parabolic function for frequency-dependent microwave resonance in the cavity enables us to experimentally determine the real and imaginary parts of the permittivity change caused by the injected charge carriers based on the Drude-Zener model, leading to the simultaneous assessment of the intrinsic charge-carrier mobility, the averaged trap depth/density, and the ratio of free-trapped charge carriers. The present frequency-dependent precise analysis of complex permittivity provides rapid and non-destructive screening of the total landscape of the charge-carrier transport at interfaces.