Yang Zhiwen, Wu Qianqian, Zhou Xiaochuan, Cao Fan, Yang Xuyong, Zhang Jianhua, Li Wanwan
The State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Nanoscale. 2021 Feb 28;13(8):4562-4568. doi: 10.1039/d0nr05025c. Epub 2021 Feb 18.
Environment-friendly high color purity blue zinc selenide (ZnSe) quantum dot-based light-emitting diodes (QLEDs) are promising candidates in next-generation display applications. However, due to the large bandgap of ZnSe (2.7 eV), the reported electroluminescence (EL) wavelengths of ZnSe QLEDs are mainly located within the range from purple to violet blue, and preparing blue emitting (>445 nm) ZnSe QLEDs remains challenging. Herein, we report a seed-mediated and double shell strategy to synthesize large-sized blue ZnSe/ZnS/ZnS core/shell/shell quantum dots (QDs). The as-prepared QDs possess excellent features including narrow full widths at half-maximum (11-19 nm), tunable emission wavelengths (410-451 nm), and high photoluminescence quantum yields (≥50%). Using ZnSe/ZnS/ZnS QDs as emitters in an inverted device, a color saturated blue QLED with an EL wavelength of 446 nm, a maximum luminance of 106 cd m, a current efficiency of 0.94 cd A, and an EQE of 2.62% is successfully fabricated. These results indicate that blue ZnSe QLEDs have great potential for future display technologies.
环境友好型、高色纯度的基于蓝色硒化锌（ZnSe）量子点的发光二极管（QLED）是下一代显示应用中很有前景的候选者。然而，由于ZnSe的带隙较大（2.7 eV），已报道的ZnSe QLED的电致发光（EL）波长主要位于从紫色到紫蓝色的范围内，制备发射蓝光（>445 nm）的ZnSe QLED仍然具有挑战性。在此，我们报道了一种种子介导的双壳层策略来合成大尺寸的蓝色ZnSe/ZnS/ZnS核/壳/壳量子点（QD）。所制备的量子点具有优异的特性，包括半高宽窄（11 - 19 nm）、发射波长可调（410 - 451 nm）以及高光致发光量子产率（≥50%）。在倒装器件中使用ZnSe/ZnS/ZnS量子点作为发光体，成功制备出了色饱和的蓝色QLED，其EL波长为446 nm，最大亮度为106 cd m，电流效率为0.94 cd A，外量子效率为2.62%。这些结果表明蓝色ZnSe QLED在未来显示技术中具有巨大潜力。
