Carrier concentration in selectively doped n-AlGaAs/GaAs single heterojunctions

Carrier concentration of a two dimensional electron gas, ns in n-AlGaAs/GaAs heterostructures is measured with varying the spacer layer thickness. Structures are designed to eliminate the effects of the charges at the surface and interface on ns. Thus obtained ns is shown to be in good agreement with calculation in which 65% of the band gap difference between AlGaAs and GaAs is assumed to appear in the conduction band. © 1990.