Size Effect of Electrical and Optical Properties in Cr²⁺:ZnSe Nanowires

Previous studies have shown that the nano-crystallization process has an appreciable impact on the luminescence properties of nanocrystals, which determines their defect state composition, size and morphology. This project aims to explore the influence of nanocrystal size on the electrical and optical properties of Cr²⁺:ZnSe nanowires. A first-principles study of Cr²⁺:ZnSe nanowires with different sizes was carried out at 0 K in the density functional framework. The Cr²⁺ ion was found to prefer to reside at the surface of ZnSe nanowires. As the size of the nanocrystals decreased, a considerable short-wave-length shift in the absorption of the vis-near infrared wavelength was observed. A quantum mechanism for the wavelength tunability was discussed.