Abstract

The development of wide bandgap II–VI heterostructures of high crystalline quality has led to progress in fundamental understanding of many-body electron-hole (e-h) interactions. Pronounced excitonic enhancements to optical gain of room-temperature ZnCdSe quantum well (QW) diode lasers have been observed.¹ At cryogenic temperatures, the e-h bound states are particularly robust, and stable excitonic molecules are found to dominate optical gain in the density regime up to about 5 × 10¹¹ cm⁻².² The biexciton binding energy has been measured to be E_B = 5.0 ± 0.5 meV in the binary ZnSe QW, where the absence of compositional disorder removes the added complications due to exciton-biexciton localization.³ Here we show evidence for the experimental observation of antibound excitonic molecular states in this system.

© 1998 Optical Society of America