QUANTUM-CONFINED STARK EFFECTS IN CDS1-XSEX QUANTUM DOTS

Quantum-confined Stark effects (QCSEs) on exciton-decay dynamics in CdS0.31Se0.69 semiconductor quantum dots (QDs) embedded in a glass matrix have been studied by time-resolved photoluminescence emission spectroscopy under different electric fields up to 2.5×105 V/cm. Under both conditions, in the absence or in the presence of an applied electric field, the exciton luminescence decay in QDs is found to follow the stretched exponential function I(t)=I0exp(-At). The decay rate A and exponent are found to vary linearly with the applied electric field, which can be accounted for by the field-induced reduction of the confined electron and hole wave-function overlap in QDs. The QCSE observed in the QDs is weaker than those observed in semiconductor quantum-well structures. © 1995 The American Physical Society.