Carrier density distribution in AlGaAs/GaAs superlattices with different numbers of quantum wells determined by capacitance-voltage profiling

Abstract

The charge carrier density distribution in uniformly doped AlGaAs/GaAs superlattices with layer thicknesses of 1.5/10 nm and different numbers of quantum wells was studied. Both energy band theory and capacitance-voltage profiling were used to determine the carrier concentration profiles of the structures. During the analysis of the experimental and simulated capacitance-voltage characteristics, it was found that the maximum electron concentrations increase with an increase in the number of quantum wells from ∼ 7.1⋅10^16 cm^−3 for three wells to ∼ 9.3⋅10^16 cm^−3 for 25 wells with an overall superlattice doping level of ∼ 10^17 cm^−3.