Nucleation Temperature-Dependent Synthesis of Polytypic CuInSe2 Nanostructures with Variable Tetrapod-Like and Core-Shell Morphologies

Despite the merits of low toxicity and light absorption/emission in the near-infrared spectral range, synthesis of polytypic CuInSe2 nanocrystals is challenging. Herein, we demonstrate a synthetic approach to produce polytypic CuInSe2 nanocrystals with variable morphologies, such as tetrapods with short or long arms; core/shell nanostructures; and hollow structures formed due to the Kirkendale effect. All polytypic CuInSe2 nanostructures realized in this work consist of a core with a chalcopyrite phase, and arms or shells with a wurtzite phase. With increasing nucleation temperature, the size of the chalcopyrite core gradually increases, while the arms or shells become smaller/thinner, due to the competition between nucleation and growth. This work provides guidance towards the synthesis of polytypic CuInSe2 nanocrystals with tunable size and morphology, and enriches the family of available CuInSe2 nanostructures.

Automated summary

This study presents a synthetic approach to produce polytypic CuInSe2 nanocrystals with variable morphologies, including tetrapods, core/shell structures, and hollow structures. These nanostructures consist of a chalcopyrite phase core and wurtzite phase arms or shells, and their size and morphology can be tuned by adjusting the nucleation temperature.