Preparation of quinary CuNixZn2−xInS4 nanocrystals with wurtzite structure and tunable band gap

Abstract

As the typical multifunctional materials, multinary metal chalcogenides have attracted tremendous attention due to their broad applications. In this work, quinary chalcogenide CuNixZn2−xInS4 (x = 0–2) nanocrystals with a wurtzite structure have been successfully synthesized for the first time by a solution method. The phase structure analysis suggests that the fabricated wurtzite phase has a disordered structure in which all metal cations share the same position and have a random distribution in the unit cell. The transmission electron microscopy results reveal that the products show a morphological evolution from sphere-like nanocrystals of CuZn2InS4 (x = 0) to bullet-like nanocrystals of CuNi2InS4 (x = 2) together with a growing particle size. All the as-obtained wurtzite CuNixZn2−xInS4 nanocrystals show a strong and broad visible light absorption. More importantly, the band gap energy of these nanocrystals can be readily tuned from 2.20 eV to 1.44 eV by varying the value of x from 0 to 2, which decreases almost linearly with the composition x. This work demonstrates a new series of I–II2–III–VI4 group chalcogenide semiconductors.