InAs/GaAs quantum dots grown on different GaAs substrates with graded In x Ga 1? x As strain-reducing layer

Abstract

Self-assembled InAs quantum dots with graded composition strain-reducing layer (SRL) grown on exact substrates were studied. It is shown that a graded In_xGa_1−xAs SRL leads to growth quality improvement, emission efficiency enhancement, and wavelength blueshift. Samples grown on 2° misoriented substrates with different In contents in graded In_xGa_1−xAs SRL were also investigated, and emission efficiency enhancement and wavelength blueshift were found when graded SRL was introduced and when the change rate of In content in graded In_xGa_1−xAs SRL was enlarged.