A double-etch process, based upon the Inoue solution, was developed for the production of pits on crystals. A comparison of the resultant etch patterns with those generated by applying the Nakagawa etchant suggested that extended defects should be attacked by the present etchant, while more detailed etching could be performed by using the Nakagawa etchant. Since extended defects were correlated with precipitates in the crystals, the etching method permitted excess concentrations of Cd or Te to be spatially resolved.

G.Brandt, H.Ennen, R.Moritz, W.Rothemund: Journal of Crystal Growth, 1990, 101[1-4], 226-31