Spectroscopic Studies Of Cdte(111) Bulk And Surface Electronic Structure

Cadmium telluride (CdTe) is a direct band-gap semiconducting material with broad applications in optoelectronic devices. Here we report on a high-resolution angle-resolved photoemission (ARPES) study of CdTe(111) surfaces prepared by sputtering and annealing that show a (2 x 2) reconstruction as observed by electron diffraction. The ARPES maps along high-symmetry directions show prominent features with their intensities modulated by varying the incident photon energy, thus suggesting important matrix element effects associated with photoemission. The results are in excellent agreement with first-principles calculations of the bulk band structure and one-dimensional density of states. A prominent surface state is observed that exhibits a (2 x 2) periodicity in agreement with the symmetry of the surface reconstruction.