Modeling for the Hybrid Schottky Junction: MXene/MAPbI₃

A hybrid MXene/MAPbI₃ Schottky junction was fabricated and systematically investigated through temperature-dependent current–voltage (I–V) and capacitance–voltage (C–V) analysis in the temperature range of 280–310 K. The device structure and energy band alignment at the MXene/MAPbI₃ interface confirm the formation of a rectifying Schottky barrier. Analysis of the forward-bias I–V characteristics reveals thermally activated carrier transport governed by thermionic emission, with an effective barrier height that decreases linearly with temperature. The extracted temperature coefficient of the barrier height is β_φ ≈ 4.3 × 10⁻⁴ eV K⁻¹, indicating significant interface-state contributions to the transport process. Log–log I–V characteristics exhibit a power-law dependence (I ∝ Vᵐ), with the exponent m decreasing with increasing temperature, consistent with trap-controlled space-charge-limited conduction at low bias and enhanced carrier injection at elevated temperatures. Reverse-bias currents increase monotonically with temperature, further supporting thermally assisted emission over the Schottky barrier. High-frequency C–V analysis shows pronounced frequency dispersion in the Mott–Schottky plots, confirming the presence of interface states at the MXene/MAPbI₃ junction. Corrected capacitance analysis yields a built-in voltage of approximately 0.7 V and a donor concentration of ~7.6 × 10¹⁴ cm⁻³. A direct current (DC) and high-frequency equivalent circuit model is proposed, incorporating depletion resistance, MXene sheet resistance, series resistance, and junction capacitance, which accurately describes both the DC transport and alternating current (AC) response of the hybrid Schottky device.