Quantum-confined Stark effect in interdiffused AlGaAs/GaAs quantum well

Abstract

The quantum-confined Stark effect is analyzed in an interdiffused Al0.3Ga0.7As/GaAs single quantum well (QW) with an as-grown well width of 100 Å, where the confinement profile is modeled by an error function. Results indicate a twofold enhancement of the Stark shift for the interdiffused quantum well over that of the square quantum well for a 50 kV/cm applied field. The fundamental exciton absorption peak also shows a much larger reduction with increasing applied field in the more extensively interdiffused QW. These characteristics may be used to realize optical modulators with higher on/off ratios and lower drive voltages.