2020/12/23 by Mariana Mar Lucas, Tiago B. Ramos, Lucas, Mariana Mar +13
Engineering · Materials Science · #78A45 #Applied Physics (physics.app-ph) #Chalcogenide Semiconductor Thin Films #Copper-based nanomaterials and applications #FOS: Physical sciences #J.2 #Materials Science (cond-mat.mtrl-sci)
paper · pdf · doi:10.48550/arxiv.2012.12598
openalex publication_date 2020/12/23 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
We demonstrate a non-destructive approach to provide structural properties on\nthe grain level for the absorber layer of kesterite solar cells. Kesterite\nsolar cells are notoriously difficult to characterize structurally due to the\nco-existence of several phases with very similar lattice parameters.\nSpecifically, we present a comprehensive study of 597 grains in the absorber\nlayer of a 1.64% efficient Cu2ZnSnS4 (CZTS) thin-film solar cell, from which 15\ngrains correspond to the secondary phase ZnS. By means of three dimensional\nX-ray diffraction (3DXRD), we obtained statistics for the phase, size,\norientation, and strain tensors of the grains, as well as their twin relations.\nWe observe an average tensile stress in the plane of the film of ~ 70 MPa and a\ncompressive stress along the normal to the film of ~ 145 MPa. At the grain\nlevel, we derive a 3D stress tensor that deviates from the biaxial model\nusually assumed for thin films. 41% of the grains are twins. We calculate the\nfrequency of the six types of \Σ3 boundaries, revealing that 180\deg\nrotations along axis <221> is the most frequent. This technique can be applied\nto polycrystalline thin film solar cells in general, where strain can influence\nthe bandgap of the absorber layer material, and twin boundaries play a role in\nthe charge transport mechanisms.\n