On the capability of revealing the pseudosymmetry of the chalcopyrite-type crystal structure

摘要

The tetragonal crystal-structure type of chalcopyrites (chemical formula A(I)B(III)C(2)(VI)) is a superstructure of sphalerite type. The c/a ratio differs generally from the ideal value 2, i.e., the crystal structure is pseudocubically distorted. For CuInSe2 and CuGaSe2 thin films, simulations demonstrate that it is theoretically possible to reveal the tetragonality in electron backscatter-diffraction (EBSD) patterns for CuGaSe2, whereas it may not be possible for CuInSe2. EBSD experiments on CuGaSe2 thin films using the "Advanced Fit" band-detection method show that it is possible to extract accurate misorientation-angle distributions from the CuGaSe2 thin film. Pole figures revealing the texture of the CuGaSe2 thin film are shown, which agree well with X-ray texture measurements from the same layer. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.