This work presents a novel combined method for the in situ analysis of electronic properties of SiC/Si heterojunctions with submicron resolution (30 nm), integrating Kelvin probe force microscopy (KPFM) and scanning tunneling spectroscopy (STS). For the first time, we have experimentally discovered a threshold activation effect of the space charge region (SCR) with a characteristic delay time of 2. 3 ± 0. 5 s and nonexponential work function relaxation (τ = 35 ± 2 s, β = 0. 65 ± 0. 05), indicating an energy distribution of interface states with a characteristic energy of 0. 12 eV. A quantitative correlation between interface morphology and spatial distribution of the density of states ({D{₈ₓ}}) has been established, showing a fivefold increase of {D{₈ₓ}} in dislocation areas (>5 × 1012 cm–2 eV–1) compared to atomically smooth terraces. A physical model linking the {D{₈ₓ}} (x) gradient with nonlinear band curving in the depletion region has been developed. Specific engineering solutions for radiation-hard converters are proposed: contact geometry optimization (30% reduction of fringe fields), A{{l}₂}{{O}₃} passivation (40% Schottky barrier reduction), and doping for relaxation time control. The results enable the targeted improvement of betavoltaic cell efficiency and the sensitivity of ionizing radiation detectors.
Dolgopolov et al. (Wed,) studied this question.