Hole eigenenergies in GaAsP/AlGaAs single quantum wells with biaxial tensile strain

Abstract

The effects of biaxial strain on the band-structure of III-V semiconductors have been investigated theoretically1,2 and experimentally3. These effects offer new degrees of freedom for heterostructure design, so-called "band-structure engineering4." In particular, when III-V semiconductors are biaxially strained, the heavy- and light-hole bands become non-degenerate, and anisotropic. The valence-band configuration that arises from biaxial tensile strain is particularly well-suited for devices that involve optical absorption. Tensile strain and the quantum size effect (QSE) of a square potential well have the opposite effect on hole energy at k=0, and if the appropriate material parameters and structural dimensions are chosen, the heavy and light-hole eigenenergies of the QW will coincide. Equivalent heavy- and light-hole excitonic resonances will result in a larger absorption coefficient5, which can improve the performance of photodiodes and high speed optical modulators6. In addition, the capability to tailor the relative energies of the heavy- and light-hole could lead to new devices that exploit the different polarization-selection rules for the heavy- and light-hole excitonic transitions6,7. In this presentation we report on the growth and photoluminescence of strained GaAsP/ALGaAs single QW′S. The combined effects of biaxial tensile strain and QSE on the hole eigenenergies will be clearly demonstrated.