TAILORING OF INTERNAL FIELDS IN INGAAS/GAAS MULTIWELL STRUCTURES GROWN ON (111)B GAAS

We present a study of internal field distributions in strained InGaAs/GaAs multiple quantum wells in p-i-n structures grown on (111) B-oriented GaAs. Room temperature photocurrent spectroscopy shows clear blueshifting of the el-hh1 transition as the well fields are reduced by external bias. The relative length of total well to total barrier material is shown to be an important factor in determining the well and barrier fields. We demonstrate a photocurrent contrast ratio of 4.5:1 for only 3 V applied bias across a 25 quantum well In0.13Ga0.87As p-i-n diode and discuss the implication of our results to the design of high performance electro-optic modulators and self electro-optic effect devices in this material system.