Colloidal Synthesis of P-Type ZnAs Nanocrystals.

Zinc pnictides, particularly ZnAs, hold significant promise for optoelectronic applications owing to their intrinsic p-type behavior and appropriate bandgaps. However, despite the outstanding properties of colloidal ZnAs nanocrystals, research in this area is lacking because of the absence of suitable precursors, occurrence of surface oxidation, and intricacy of the crystal structures. In this study, a novel and facile solution-based synthetic approach is presented for obtaining highly crystalline p-type ZnAs nanocrystals with accurate stoichiometry. By carefully controlling the feed ratio and reaction temperature, colloidal ZnAs nanocrystals are successfully obtained. Moreover, the mechanism underlying the conversion of As precursors in the initial phases of ZnAs synthesis is elucidated. Furthermore, these nanocrystals are employed as active layers in field-effect transistors that exhibit inherent p-type characteristics with native surface ligands. To enhance the charge transport properties, a dual passivation strategy is introduced via phase-transfer ligand exchange, leading to enhanced hole mobilities as high as 0.089 cm V s. This study not only contributes to the advancement of nanocrystal synthesis, but also opens up new possibilities for previously underexplored p-type nanocrystal research.