Impact of the Graded-Gap Layer on the Admittance of MIS Structures Based on MBE-Grown <italic>n</italic>-Hg1 - <italic>x</italic>Cd<italic>x</italic>Te (<italic>x</italic> = 0.22-0.23) with the Al2O3 Insulator.

The impact of the presence of the near-surface graded-gap layers with an increased content of CdTe on the admittance of MIS structures based on MBE-grown <italic>n</italic>-Hg_{1-<italic>x</italic>}CdxTe (<italic>x</italic> = 0.22-0.23) with the Al₂O₃ insulating coating has been experimentally studied. It has been shown that the structures with a gradedgap layer are characterized by a deeper and wider capacitance dip in the low-frequency capacitance-voltage (CV) characteristic and by higher values of the differential resistance of the space-charge region than the structures without such a layer. It has been found that the main features of the hysteresis of capacitance dependences typical of the graded-gap structures with SiO₂/Si₃N₄ are also characteristic of the MIS structures with the Al₂O₃ insulator. The factors that cause an increase in the CV characteristic hysteresis upon formation of the graded-gap layer in structures with SiO₂/Si₃N₄ or Al₂O₃ are still debatable, although it may be assumed that oxygen plays a certain role in formation of this hysteresis. [ABSTRACT FROM AUTHOR]