Twinning in Cu(In,Ga)S₂

Abstract

Epitaxial thin films of CuIn1‐xGaxS2 (0 ≤ x ≤ 1) were grown on single‐crystalline (111)cub‐oriented silicon substrates by means of molecular beam epitaxy from elemental sources. Employing reflection high energy electron diffraction and Rutherford backscattering spectroscopy the twinning characteristics and the composition of the films were determined, respectively. X‐ray diffraction measurements in transmission geometry were performed to determine the lattice mismatch to the substrate. The degree of twinning of the epitaxial films shows a highly non‐linear dependence on their gallium content x. The transition point between high twinning regime (low gallium content) and low twinning regime (high gallium content) is at xt = 0.74. The twinning characteristics are discussed and compared to lattice mismatch and metastable ordering types. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Morphology and structure evolution of Cu(In,Ga)S2 films deposited by reactive magnetron co-sputtering with electron cyclotron resonance plasma assistance

“…%) in our films, here it is most probably caused by twin stacking faults originating from the (112) diffraction peak. Oishi et al 17 and Cieslak et al 18 reported {112} twins in the Cu(In, Ga)S 2 films on Si(100) and Si(111), respectively. Rodriguez-Alvarez et al 19 also reported a signature that does not correspond to the ideal chalcopyrite structure of CIGSe and attributed this to stacking faults within the bulk of the films by modeling diffraction patterns of faulted CIGSe with the software DIFFaX.…”