Direct Observation of the Conventional Epitaxial and Novel Heteroaxial ZB-WZ Stacking Faults

Abstract

Compared to the conventional ZB-WZ stacking fault that aligns with the crystal growth axis, a novel heteroaxial ZB-WZ stacking fault axis that intercepts the growth axis by 70.3° is observed and analyzed in this report. The formation of the reported heteroaxial ZB-WZ stacking fault is attributed to the nanocrystals’ tendency to achieve the lowest possible systematic disorder by avoiding atomic array distortion at the intersection of two tetrahedral polytypic interphases.

Resolving Multielement Semiconductor Nanocrystals at the Atomic Level: Complete Deciphering of Domains and Order in Complex CuαZnβSnγSeδ (CZTSe) Tetrapods

“…Different from our previous research on a similar CZTSe tetrapod with 3 different types of Bravais lattice boundary defects, namely, polytypic, epitaxial, and heteroaxial ZB-WZ stacking faults, the 4 different domains discussed in this study are interlaced without Bravais lattice boundary defects. All 4 chemical ordering domains of different volumes with various chemical stoichiometries all contribute to the overall chemical stoichiometry, resulting in the noninteger stoichiometry, Cu 2.6 Zn 1.1 SnSe 3.2 (Figure S2).…”

“…Herein, by imaging nanocrystals with multiple crucial zone axis orientations, we present chemical ordering analysis on highly complex quaternary element semiconductor nanocrystals with low-symmetry crystal domains. Morphological analysis of CZTSe tetrapod NCs 12,13 (∼48 nm) was carried out through the compilation of TEM imaging and cation−anion modeling (Figure 1a−d, Figure S1). As displayed in Figure 1a, CZTSe tetrapods have a 3D tetragonal structure with wurtzite-derived arms (original phase WZ P6 3 mc and a zinc-blende-derived core (original phase ZB F4̅ 3m).…”

“…Morphological analysis of CZTSe tetrapod NCs , (∼48 nm) was carried out through the compilation of TEM imaging and cation–anion modeling (Figure a–d, Figure S1). As displayed in Figure a, CZTSe tetrapods have a 3D tetragonal structure with wurtzite-derived arms (original phase WZ P 6 3 mc and a zinc-blende-derived core (original phase ZB F 4̅3 m ).…”