Asymmetric trap-assisted transport in silicon: Crossover beyond Poole-Frenkel scaling

We demonstrate nonlinear, asymmetric charge transport in Al/p-Si and n-SnS/p-Si structures governed by field-induced trap-assisted emission. The I − V characteristics reveal deviations from Ohmic behavior, captured by a generalized exponential model with voltage and current offsets. Data of studied devices and various bias conditions collapse onto a single scaling curve, thus providing compelling evidence for a crossover from Poole to Frenkel-type conduction. Gate-dependent modulation confirms electrostatic control of the emission barrier. The present study only focusses on identification of the conduction mechanism and the findings uncover a tunable transport regime relevant to resistive switching, electrostatically tunable trap assisted transport, and trap-engineered semiconductor systems.