Energy Material Advances / 2021 / Article / Fig 1

Research Article

Pushing the Band Gap Envelope of Quasi-Type II Heterostructured Nanocrystals to Blue: ZnSe/ZnSe1-XTeX/ZnSe Spherical Quantum Wells

Figure 1

Structural characteristics and optical properties of ZnSe/ZnSe1-XTeX/ZnSe SQW NCs. (a) Schematic illustration (left) and transmission electron microscopy (TEM) image (right) of ZnSe ()/ZnSe1-XTeX ()/ZnSe () NCs. Scale bar is 20 nm. (b) A photographic image of ZnSe ()/ZnSe1-XTeX ()/ZnSe () NC dispersions with varying Te ratios. varies from 0.03 (left) to 0.50 (right). (c) Schematics illustrating the bulk band structure of ZnSe/ZnSe1-XTeX/ZnSe NC (black solid line) and electron (blue) and hole (red) wave function at their lowest quantized energy state. The change in Te content () alters the energy states for the hole (left), whereas the modulation of ZnSe shell thickness alters the energy states for electron (right). (d) Absorption (dashed line) and PL spectra (solid line) of ZnSe ()/ZnSe1-XTeX ()/ZnSe NCs with varying Te ratios () and ZnSe shell thicknesses (). The inset displays PL QYs of ZnSe/ZnSe1-XTeX/ZnSe NCs with varying Te contents () and ZnSe shell thicknesses (, 1.2, 1.8, and 2.4 nm).