We performed a complex secondary ion mass spectroscopy (SIMS) 3D analysis of solar cell structures based on II-VI semiconductors. The chemical composition analysis, as well as the depth distribution of the main elements and contamination were done for AuCu/CdTe/CdS/conducting glass structures. A structure where the II-VI compounds were grown by pulsed laser ablation (PLA) was compared with another structure grown by ion sputtering deposition (ISD). In both cases contamination due to O, C and H was found at high concentrations, particularly at the boundaries between crystallites. In addition to the SIMS depth profiling, the surface roughness (SR) was analysed by atomic force microscopy (AFM). Poor SIMS depth resolution was correlated to high surface roughness. The root-mean-square of the surface roughness (R rms ) was found to be higher for ISD than for PLA structures. In addition, the lateral distribution of the main components and contamination were observed in the microscope mode with a resolution of about 1 µm. A larger lateral contamination was correlated to a larger R rms of the analysed surface. Experimental 'diffusion' tails of Cu and Au from the ohmic contacts on the CdTe layer are also explained by a high R rms for this layer.

No abstract

GaSb ingots were oriented along the low index crystal planes, (111), (ii0), and (I00), using an optical technique. The surfaces etched with an HCI:CuCI solution show very well-defined figures, revealing the high symmetry of the surface orientations. The reflectograms obtained from these surfaces allow the precise orientation of GaSb crystals, and they can be used to distinguish between the (III)A and (III)B faces.

A Chemical Etching Solution for the Determination of the Crystallographic Orientation of GaSb by Optical Reflectograms.-Etching of GaSb surfaces with a solution of 1.0 N CuCl in conc. HCl produces sharp figures on the low index planes, (111), (110), and (100) , which allow the optical orientation with an accuracy comparable with that obtained by using X-rays. In particular, the reflectograms obtained from the (111)A and (111)B surfaces are clearly different and allow their easy identification. -(GODINES, J. A.; DE ANDA, F.; CANALES, A.; BANOS, L.; RIOS-JARA, D.; J. Electrochem.