Abstract
A theoretical analysis, using a Schrödinger solver, is made to calculate the electric field-dependent interband transitions in a Si/Si
1−
x
Ge
x
/Si double QW strain-compensated in relaxed Si
1−
y
Ge
y
barriers. The conduction and the valence band present a W-like potential profile, resulting in a quasi-type I heterostructure. Three peculiar features are revealed as the electric field is increased: (i) two uncoupled e
11 and e
12 electron levels are generated, (ii) the e
11–hh
1 fundamental transition due to first silicon QW exhibits a red shift in emission energy while the e
12–hh
1 transition energy is bleu shifted, (iii) an improved wave function overlap for the e
11–h
1 fundamental transition, the latter property showing the advantage having two adjacent QWs in this W architecture.