Radiative recombination transitions between states of bound and free excitons in uniaxially strained cadmium telluride

The way that emission lines from bound and free excitons in CdTe shift, split, and change in intensity under uniaxial strain have been investigated theoretically and experimentally. The nonlinear shift observed in the energy positions of peaks due to acceptor-bound excitons is caused by strong spin-spin interaction in the system of two heavy holes. A nonmonotonic dependence and abrupt quenching of the intensity of emission from acceptor-bound excitons in the high-strain regime (pressures P>1 kbar) with a simultaneous buildup in the free-exciton emission line has been observed. The theoretical model considers two basic mechanisms for recombination-radiative and Auger recombination. The results which were obtained can be used to identify types of defects in CdTe, and to determine local mechanical stresses in CdTe-based heterostructures. 17 refs., 5 figs