Exciton Line Broadening In Cd sub x Zn sub (1-x) Te/ZnTe Multiple Quantum Wells.

We have investigated Cd sub x Zn sub (1-x) Te/ZnTe MQWs using absorption techniques. We have observed sharp excitonic features at low temperatures which strongly broaden at room temperature. The strength of the exciton-phonon coupling is determined from linewidth analysis. The large measured coupling explains the lack of well defined exciton resonances at room temperature, an important consequence for their use as optoelectronic devices.