Fig. 3.

Impedance spectroscopy on p-doped films. Arrhenius-type doping activation determined by Mott-Schottky analysis on ITO/host:F₆-TCNNQ(50 nm)/Al diodes with a ZnPc or b MeO-TPD as host, respectively. c C(f) spectra of the ZnPc:F₆-TCNNQ device at zero bias and varying sample temperature from RT to 20 K in steps of ∆T = 10 K. Doping freeze-out causes steadily increasing depletion and, for T ≤ 100 K, vanishing trap response. d Depletion width w calculated from (b) at 10 and 30 kHz, and ε_r = {4.7; 5.3}