Investigating the charge relaxation in semiconductor heterostructures with quantum wells by means of admittance spectroscopy

Charge is evaluated as a function of temperature, based on the analysis and nmathematical processing of experimental capacitance-voltage characteristics obtained in frequency range of 1 kHz to 1 MHz and temperature range of 320 to 10 K for samples of InGaAs/GaAs heterostructures with quantum wells (QWs) and ultrathin InAs/GaAs wetting layers specially prepared for admittance measurements. It is found that the charge in the QW determined by the apparent concentration profiles from experimental C-V characteristics monotonically increases compared with the charge in quantum wells.