Observation of antisite domain boundaries in Cu2ZnSnS4 by atomic-resolution transmission electron microscopy

摘要: Atomic resolution transmission electron microscopy has been used to examine antisite defects in Cu2ZnSnS4 (CZTS) kesterite crystals grown by a hot injection method. High angle annular dark field (HAADF) imaging at sub-0.1 nm resolution, and lower magnification using reflections sensitive cation ordering, are reveal domain boundaries (ADBs). These boundaries, typically 5–20 apart, extending distances of 100 or more into the crystals, lie on variety planes have displacements type ½[110] ¼[201], which translate Sn, Cu Zn cations positions. It is shown that some ADBs describe change local stoichiometry removing S either atoms, implying these can be electrically charged. The observations also showed marked increase disorder regions within 1–2 grain surfaces suggesting growth ordered crystal takes place interface with disordered shell. estimated contribute average ∼0.1 defect pairs per unit cell. Although this up an order magnitude less than highest densities reported, presence high may charged suggests significant influence efficiency CZTS solar cells.