Breaking AgInTe₂ Quantum Dot Chain to Fabricate AgInTe₂-ZnS Janus Nanocrystals

Colloidal multinary chalcogenides (MnCs) have emerged as excellent optoelectronic materials, where S- and Se-based MnCs show considerable progress; however, the Te counterpart suffers from detrimental surface oxidation. Moreover, Te-based I-III-VI MnCs (e.g., AgInTe₂) tend to form a one-dimensional (1-D) anisotropic structure via the self-assembly of surface-oxidized Te, thus restricting the isolation of AgInTe₂ quantum dots (QDs). We report successful control of the self-assembly of Te-based MnCs to arrest the growth of AgInTe₂ QDs by using a synergistic capping agent (dodecanethiol and oleic acid). The reaction proceeds with several intermediates, including hexagonal microrods (MR), tetragonal QDs in a chain arrangement, and tetragonal MRs. Importantly, we note that the incorporation of ZnS QDs triggers the breaking of the chain arrangement of the AgInTe₂ QDs and the emergence of evenly distributed AgInTe₂-ZnS Janus nanocrystals with significantly reduced long-term Te-oxidative properties. Arresting the AgInTe₂ QD chain and the subsequent Janus nanocrystal formation could have promising opportunities for 1-D charge hopping and efficient charge transport for optoelectronic applications, respectively.