| 초록 |
ZnSe (bulk=2.7 eV) quantum dots (QDs) are fabricated with lanthanide-Eu, the resulting QDs can achieve both visible and near-infrared fluorescent properties and promising candidates for fabricating a new class of light-converting materials. The broad spectrum was attributed to the 4F65D1→4F7 transition when the Eu2+ emission was increased from 450 to 550 nm. Eu3+ shows characteristic red emission peaks at 579, 592, 615, 651, and 700 nm owing to the electronic transition of 5D0→7Fj (j = 0, 1, 2, 3, 4). In this study, we report the in-situ synthesis of ZnSe:Eu by increasing Eu precursor mol concentration, which is a color-tunable, hybrid material emitting multimodal-emission. The expected Eu luminescence and structure property of the ZnSe QDs was verified by UV/vis, PL and XRD and XPS. Compared to the diffraction peaks of pristine ZnSe, the corresponding peaks for the ZnSe:Eu QDs are shifted, by about 0.43°, to larger angles, because the ionic radius of Eu3+ (0.95 Å) is larger than that of Zn2+ (0.74 Å). In addition, the intensity of the XRD peaks decrease monotonously, while the widths of the obtained XRD peaks show a systematic broadening with increasing Eu precursor mol concentration. It is also probably associated with lattice disorder and strain induced in the ZnSe lattice due to the substitution of Zn2+ ions by Eu3+ ions of comparatively higher ionic radius. Thus, the crystalline quality of Eu3+-doped ZnSe QDs decreases with Eu3+ doping. |
