Philippe Boring

Electronic Structure and Optical Properties of (Ga, In)As-(Ga, Al)As Quantum Wells and Superlattices under Internal and External Strain Fields

We present a detailed study of the electronic structure and optical properties of (Ga,In)As-(Ga,AI)As strained-layer quantum wells and superlattices grown along either the (001) and (111) directions.

Photo-induced screening of the excitonic interaction in ZnSe-ZnTe type II strained-layer superlattices

Abstract We report the observation of nonlinear optical properties of ZnSe-ZnTe superlattices under photo-injected carriers, at pumped liquid helium temperature. Identification of several transitions measured by transmission on samples grown by metalorganic vapour phase epitaxy and etched away from the GaAs substrate is made in the context of the envelope function approach. This reveals that the conduction to valence band line-ups are type II in these samples. This situation is invoked in order to interpret the efficiency of the exciton screening.

MOVPE-growth and physics of ZnSe-ZnTe superlattices

Abstract We have grown short-period ZnSe-ZnTe superlattices using low-pressure MOVPE. The influence of the growth parameters was investigated in detail. Combination of optical characterization with a tight-binding calculation gives a value of 200 meV for the strain-free valence band offset.

Tailoring of the Valence Band Offset in the ZnSe/ZnTe Strained-Layer Superlattices Using Strong Built-in Strain Fields

ZnSe/ZnTe strained-layer short period superlattices have been grown by MOVPE. Using well adapted buffer layers, we could tune the internal built-in strain of the individual layers. We studied both free standing superlattices and strained-layer superlattices lattice matched to ZnTe. We observe that the tuning of the valence band offset by the internal strain can produce a switching of the superlattice band gap from type II e 1 hh 1 to type I e 1 lh 1 . Photoreflectance investigations enabled us to measure excited state transitions allowing us to obtain the strain free valence band offset with considerable accuracy