High color rendering index white LEDs fabricated using InP/ZnS green-emitting quantum dots and InP/ZnSe/ZnS red-emitting quantum dots

Abstract

Quantum dots (QDs) have the advantages of spectrally adjustable, high quantum yield and narrow half-peak width, and are the most potential light-converting materials for white light that achieve high color rendering index and high saturation. The InGaN blue light chip currently used excites Ce-doped yttrium aluminum garnet (YAG: Ce3+) yellow phosphor, and the white light-emitting diode (WLED) realized exhibits color rendering index (CRI) <80 and an unsatisfactory color coordinate because of lack of red spectral components. In order to improve the CRI of white LEDs, in this paper, we fabricated InP / ZnS green-emitting QDs and InP / ZnSe / ZnS red-emitting QDs, and excited YAG: Ce3+ yellow phosphor, InP / ZnS green-emitting QDs and InP / ZnSe / ZnS redemitting QDs with blue chip , made WLED (I), and compared with WLED (II) generated by using blue LED chip to excite YAG: Ce3+ yellow phosphor. The result shows that the WLED (I) achieves a CRI of 90.3 at a driving current of 5 mA. The Commission International de L’Eclairage (CIE) chromaticity coordinates are (0.3393, 0.3342), and the correlated color temperature (CCT) is 5186K, which is high quality white light close to sunlight.