Capacitance-voltage characteristics of the p-Cd0.27Hg0.73Te-based structures with a wide-gap graded-gap surface layer

摘要

Capacitance-voltage characteristics of the structure In-SiO2-(graded-gap layer Cd0.71-,0.27Hg0.29-0.73Te)-p-Cd0.27Hg0.73Te-GaAs are investigated at temperatures of 80 K and higher. The characteristics have the hysteresis, specifically, the characteristic is similar to a forward portion of the usual high-frequency characteristic (from enrichment to inversion), while the reverse portion has an extended plateau, in which the capacitance of the space-charge region is larger by a factor of approximately 2. To interpret the capacitance-voltage characteristic, the effect of partial screening of the graded-gap part of the space-charge region from the electric field of the test signal, as well as the effect of formation of the potential electron well near the surface due to the recharging of donor levels are considered.