The effects of several reducing and oxidizing etchants upon CdTe surfaces were characterized by using photoluminescence methods. For the purposes of excitation, several lines from 3 different types of gas laser, emitting at 325nm (He-Cd), 488nm (Ar-ion), and 632.8nm (He-Ne) were used. The corresponding light-penetration depth varied from about 25 to 200nm. An analysis of the photoluminescence as a function of depth not only permitted the characterization of the type of defect which was created by etching, but also its distance from the treated surface. Suitable etching solutions produced surfaces with a crystalline quality which was comparable to that of a cleaved surface, and the photoluminescence spectra did not depend upon the excitation energy.

J.Garcia-Garcia, J.Gonzalez-Hernandez, J.G.Mendoza-Alvarez, E.L.Cruz, G.Contreras-Puente: Journal of Applied Physics, 1990, 67[8], 3810-4