Observation of Phase Transitions in an Electron–Hole System Associated with Dislocation Cores in Cadmium Telluride

Evolution of the fine structure of dislocation microphotoluminescence lines in cadmium telluride with a decrease in the optical-excitation power density has been demonstrated at low (5 K) temperatures. The character of this evolution for each of the three bands under investigation (Y1 (~1.47 eV), Y2 (~1.49 eV), and Y3 (~1.51 eV)) indicates the existence of a transition from electron–hole plasma to exciton states. It is established that the fine structure of band Y3 at the excitation densities of 0.1–0.01 W/cm2 exhibits signs of formation of metastable states with participation of a dislocation core.