OBSERVATION OF THE QUANTUM-CONFINED STARK-EFFECT IN ZNSE ZNCDSE SINGLE-QUANTUM-WELL SYSTEMS/

We report the observation of the quantum-confined Stark effect (QCSE) in ZnSe/ZnCdSe single quantum wells grown by molecular beam epitaxy, u sing photoluminescence. In our experiments the electric field was appl ied via a reverse-biased Schottky barrier contact. To our knowledge, t his is the first observation of the QCSE in any wide gap II-VI semicon ductor heterostructure. Significant red shifts, typically 10-15 meV, a re detected before quenching. An associated reduction in the transitio n intensity, consistent with the QCSE is clearly observed. The depende nce of these results will be discussed as a function of quantum well d epth and thickness. Complete quenching of the luminescence is observed with applied voltages as low as 5 V. In addition, at lowest voltages, we also detect small blue shifts (up to 4 meV), which we attribute to the interaction between the externally applied electric field and the built-in field of the structure.