Bandgaps and band offsets in strain-compensated InGaAs/InGaAsP multiple quantum wells

摘要

In terms of the parameter interpolation principle, calculations are performed for bandgaps and band offsets in strain-compensated In$-z$/Ga$-1$MIN@z$/As/In$-x$/Ga$- 1$MIN@x$/As$-y$/P$-1$MIN@y$/ multiple quantum well structures on InP. Relations between strains and material compositions in In$-z$/Ga$-1$MIN@z$/As wells and In$-x$/Ga$- 1$MIN@x$/As$-y$/P$-1$MIN@y$/ barriers are analyzed, and relative ranges of strains are evaluated. Bandgaps of In$- z$/Ga$-1$MIN@z$/As wells and In$-x$/Ga$-1$MIN@x$/As$-y$/P$- 1$MIN@y$/ barriers for heavy- and light-holes are studied, and relative ranges of bandgaps are estimated. Dependence of band offsets of conduction band and valence band for heavy- and light-holes on strain compensation between In$-z$/Ga$- 1$MIN@z$/As wells and In$-x$/Ga$-1$MIN@x$/As$-y$/P$- 1$MIN@y$/ barriers is investigated, and variation of band offsets versus strain compensation is discussed. The computed results show that strains, bandgaps and band offsets are functions of material compositions, strain compensation changes the band offsets, and hence modifies the band structures and improves the features of strain- compensated multiple quantum well optoelectronic devices.