Formation of five-fold twinning electron diffraction pattern and twinning bands in bulk CuIn₃Se₅ via hot deformation

We analyzed bulk CuIn₃Se₅ alloys via transmission electron microscopy (TEM). The high-resolution TEM micrographs showed many twinning bands and doublet periodicity of the (0 0 2) lattice planes and corresponding fast Fourier transform patterns revealed the superstructure reflections. The selected area electron diffraction pattern showed the nearly five-fold rotation diffraction spots, which resulted from the four-fold rotation twinning at one point and other twinning bands. The TEM results indicated the CuIn₃Se₅ alloy deformed by hot press had many multiple-twinned crystallites as well as a high density of twinning in the {1 1 2} planes.