Impedance, admittance or current–voltage? What each measurement really tells about charge transport in deepblue hosts

Host mobilities are usually quoted from one technique without saying what that technique can actually pin down. Using single-carrier devices of three deep-blue phosphine-oxide hosts, we credit impedance spectroscopy (IS), admittance and steady-state current–voltage (J–V ) data each with what they can fix. Documented rules for point selection, dispersion and transport onset make the published IS mobilities reproducible. Quality-gated admittance pins down the electrostatic state of the films: its ac conductance exceeds the dc conductance of the corresponding device types by up to several hundred times, and no transit feature is resolved in the clean band. Gated J–V sweeps locate a high-slope onset consistent with trap filling under stated assumptions, and the spread between successive sweeps of one device sets a built-in check before hosts are ranked. The result is a constraint map that assigns each technique its role and makes host-transport claims auditable.