Excitonic line broadening in bulk grown Cd1−xZnxTe

Abstract
Cd1−xZnxTe crystals grown by the traveling heater method have been investigated by low-temperature photoluminescence. The excitonic energy gap as a function of the alloy composition was determined over the complete range of x=0 to x=1. The composition dependent broadening of the neutral acceptor bound exciton (A 0X) line was determined. Theoretical calculations, where the A 0X exciton is treated within the pseudodonor model and the conduction/valence band offset between CdTe and ZnTe is taken into account, give close agreement with the experiment for x≤0.77. Evidence for clustering of Zn atoms is found for x≥0.77.