Li Jiasheng, Tang Yong, Li Zongtao, Ding Xinrui, Yu Binhai, Lin Liwei
Engineering Research Center of Green Manufacturing for Energy-Saving and New-Energy Technology , South China University of Technology , Guangdong 510640 , China.
Foshan Nationstar Optoelectronics Company Ltd. , Foshan 528000 , China.
ACS Appl Mater Interfaces. 2019 May 22;11(20):18808-18816. doi: 10.1021/acsami.8b22298. Epub 2019 Apr 26.
Quantum-dot (QD) white light-emitting diodes (LEDs) are promising for illumination and display applications due to their excellent color quality. Although they have a high quantum yield close to unity, the reabsorption of QD light leads to high conversion loss, significantly reducing the luminous efficacy and stability of QD white LEDs. In this report, SBA-15 mesoporous particles (MPs) with two-dimensional hexagonal pore structures (2D-HPS) are utilized to largely enhance the luminous efficacy and color-conversion efficiency of QD white LEDs in excess of 50%. The reduction in conversion loss also helps QD white LEDs to achieve a lifetime 1.9 times longer than that of LEDs using QD-only composites at harsh aging conditions. Simulation and testing results suggest that the waveguide effect of 2D-HPS helps in reducing the reabsorption loss by constraining the QD light inside the wall of 2D-HPS, decreasing the probability of being captured by QDs inside the hole of 2D-HPS. As such, materials and mechanisms like SBA-15 MPs with 2D-HPS could provide a new path to improve the photon management of QD light, comprehensively enhancing the performances of QD white LEDs.
量子点（QD）白光发光二极管（LED）因其出色的色彩质量而在照明和显示应用方面颇具前景。尽管它们具有接近1的高量子产率，但量子点光的再吸收会导致高转换损耗，显著降低量子点白光发光二极管的发光效率和稳定性。在本报告中，具有二维六角形孔结构（2D-HPS）的SBA-15介孔颗粒（MPs）被用于大幅提高量子点白光发光二极管的发光效率和颜色转换效率，提高幅度超过50%。转换损耗的降低还帮助量子点白光发光二极管在苛刻的老化条件下实现了比仅使用量子点复合材料的发光二极管长1.9倍的寿命。模拟和测试结果表明，二维六角形孔结构的波导效应有助于通过将量子点光限制在二维六角形孔结构的壁内来降低再吸收损耗，降低被二维六角形孔结构孔内量子点捕获的概率。因此，像具有二维六角形孔结构的SBA-15介孔颗粒这样的材料和机制可以为改善量子点光的光子管理提供一条新途径，全面提高量子点白光发光二极管的性能。
