Conduction band offset of pseudomorphic InAs/GaAsdetermined by capacitance- voltage spectroscopy

摘要

InAs-±-layers embedded in a GaAs matrix are investigated by capacitance-voltage(C-V) measurements. The high resolution of the apparent carrier distribution (ACD) isconfirmed by the experimental observation of the electronic decoupling of two InAs-insertionsin samples with varying GaAs-interlayer thickness. By means of a direct method, I.e., withoutthe extensive self-consistent solution of Poisson and Schr¨odinger equation, the conductionband offset △Ec at the interfaces between an InAs-monolayer (ML) and a GaAs matrixwas investigated. The determined value of △Ec= 670 meV corresponds well to literature.Furthermore, using this direct method, the activation energy of the single electron level (SEL)in the InAs ML has been determined to be 61 meV.