High Color-Rendering Index and Stable White Light-Emitting Diodes Based on Highly Luminescent Quantum Dots |
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Authors: | Jinke Bai Meilun Zhang Ruiyao Jiang Ziming Wu Linfeng Wang Xiao Jin Qinghua Li Yuxiao Wang Xueru Zhang Yinglin Song |
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Institution: | 1. Department of Physics, Harbin Institute of Technology, Harbin, 150001 P. R. China;2. Guangdong Provincial Key Laboratory of Development and Education for Special Needs Children, Lingnan Normal University, Zhanjiang, 524048 P. R. China |
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Abstract: | Solid-phase color converter-based quantum dots (QDs) white light-emitting diodes (WLEDs) have become promising next-generation solid-state light sources. However, the development of these WLEDs’ production still suffers from constraints involving insufficient color-rendering index (CRI), low color stability, and short operation lifetimes. Here, thick-shell Cd0.05Zn0.95S/CdSe/CdxZn1–xS spherical quantum wells are developed with good color tunability from green to red regions and high photoluminescence quantum yield (up to 88% for green wavelengths). QDs with five emission colors are used to fabricate a series of WLEDs, which possess a good correlated color temperature tunability from warm (3210 K) to cool (22 000K) white light, and a high CRI Ra (>90). Specifically, the neutral white light device with Commission Internationale de l´Eclairage (CIE, International Commission on illumination) of (0.36, 0.36) and the standard white light device with CIE of (0.33, 0.33) achieve a CRI Ra up to 95.8 and 95.11, respectively, they also exhibit long operating life and great color stability. These results indicate that the improvement of the performance and stability of the WLED based on thick-shell spherical quantum wells is remarkable progress in the commercialization of QD-based solid-state lighting. |
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Keywords: | color stability operation lifetimes quantum dots thick-shell white light-emitting diodes |
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