GaAsSb layer with graded composition reducing stress in InAs/GaAs quantum dots

摘要

The multilayer semiconductor epitaxial structure of InAs / GaAs quantum dots and GaAsSb cover and the stress-reducing layer of sparing type heterojunction between InAs quantum dots and GaAsSb layer and permitting issuance of electroluminescence at telecommunication wavelength of 1300 nm. Maintaining heterojunction type I for these wavelengths is achieved gradovaným composition GaAs.sub.1-xnSb.sub.xnvrstvy so that the GaAsSb layer being lower concentration of Sb (x = .03 to .09) immediately adjacent the quantum dots, (thereby securing a sufficient barrier for holes in InAs quantum dots and their localization in quantum dots) in the direction of epitaxial growth the concentration of antimony in the GaAsSb rise to the maximum concentration which is in the range x = 0.15-0.30. (This provides a necessary lowering of tensions within the quantum dot and an extension of the emitted wavelengths). The structure can be realized with the continuous changes of the concentration of antimony or stepwise by using two or more layers.