Non-zone-folded transition-energy calculations for quantum-confined Stark effect in Si1−xGex/Si quantum wells

Abstract

We report calculated bound-state transition energies at 77 K for symmetrically strained Si1−xGex/Si quantum wells grown on (100) Si substrates. The red shift in transition energies with bias due to the quantum-confined Stark effect is also examined. Transition energies are plotted as a function of Ge concentration, quantum-well thickness, and applied electric field. The calculations are based on phenomenological deformation potential theory and the envelope function method popularized by G. Bastard [Phys. Rev. B 24, 4714 (1981)]. The results presented here are useful for the design of Si1−xGexSi optoelectronic modulators operating at 1.3 and 1.55 μm.