Depth resolved cathodoluminescence and microanalysis of ZnCdSe/ZnSe quantum well heterostructures

The novel approaches to study the II–VI-based laser heterostructures using cathodoluminescence and electron probe microanalysis techniques are described in detail. The heterostructures were grown by molecular beam epitaxy on GaAs (0 0 1) substrates and consist of bottom and top ZnMgSSe cladding layers and ZnCdSe/ZnSe quantum well embedded in Zn(Mg)SSe/ZnSe graded index waveguide. The microanalysis technique based on the intensity measurements of characteristic X-rays has been applied to determine both the composition of ZnCdSe quantum well layer and its position within heterostructure. The depth resolved cathodoluminescence technique has been applied for the transport studies of electron beam generated carriers in heterostructure. The cathodoluminescence intensity of ZnCdSe quantum well has been measured as a function of electron beam energy. The Monte-Carlo simulations of carrier generation distribution within the heterostructure under electron beam irradiation have been used for fitting of experimental results. It made possible the nondestructive characterization of the multilayer heterostructure to estimate both deficiency and carrier transport length.

► Electron probe microanalysis technique for multilayer heterostructures was developed.
► The composition and depth position of ZnCdSe QW in heterostructures were defined.
► The depth resolved cathodoluminescence was used to study charge carrier transport.
► Monte-Carlo simulation of carrier generation distribution in depth was used.
► The carrier transport properties of heterostructure depend on its quality.