Superior color rendering with a phosphor‐converted blue‐cyan monolithic light‐emitting diode

Abstract

The future generation of modern illumination should not only be cheap and highly efficient, but also demonstrate high quality of light, light which allows better color differentiation and fidelity. Here we are presenting a novel approach to create a white solid-state light source providing ultimate color rendition necessary for a number of applications. The proposed semi-hybrid device combines a monolithic blue-cyan light emitting diode (MBC LED) with a green-red phosphor mixture. It has shown a superior color rendering index (CRI), 98.6, at correlated color temperature of around 3400 K. The MBC LED epi-structure did not suffer from the efficiency reduction typical for monolithic multi-color emitters and was implemented in the two most popular chip designs: "epi-up "and "flip-chip ". Redistribution of the blue and cyan band amplitudes in the white-light emission spectrum, using the operating current, is found to be an effective tool for fine tuning the color characteristics.

Novel efficient SrMgY3(SiO4)3F:Ce3+,Tb3+ phosphor with tunable color and thermal stability through energy transfer

“…In recent years, rare earth-activated phosphors have been widely used in white light-emitting diodes (w-LEDs) due to their advantages of high efficiency, long life, durability, energy-saving, and environmental protection. [1][2][3][4][5][6] The most widely used technique for fabricating w-LEDs in commerce is to coat yellow-emitting YAG:Ce 3+ phosphors onto blue GaN chips. [7][8][9][10] However, these w-LEDs lack the red component in their emission spectrum, limiting their application in indoor lighting, medical, and many other fields.…”

“…In recent years, rare earth‐activated phosphors have been widely used in white light‐emitting diodes (w‐LEDs) due to their advantages of high efficiency, long life, durability, energy‐saving, and environmental protection 1–6 . The most widely used technique for fabricating w‐LEDs in commerce is to coat yellow‐emitting YAG:Ce 3+ phosphors onto blue GaN chips 7–10 .…”

An Investigation on CCT and Ra Optimization for Trichromatic White LEDs Using a Dual-Weight-Coefficient-Based Algorithm

“…For the second type, Zhu et al [14] conducted a comprehensive study on illumination performances of the perovskite-based LED with four humps. Titkov et al [15] proposed a semi-hybrid device, which combined monolithic blue-cyan LED with green-red phosphor mixture, exhibiting the highest Ra of 98.6 at CCT of 3400 K. Yuan et al [16] manufactured a trichromatic WLED, which constitutes of blue-pump carbon dots and phosphor glass, realizing the highest Ra of 92.9 at CCT of 3610 K. Among these studies, a variety of methods are conventionally used, such as the multiple Gaussian function method [17], least-squares method [18], and iterative method of gradient descent [19]. However, these methods focus on improving the accuracy and the feasibility, as well as developing light-conversion material species with superior chromaticity; few of them discuss the improvement strategy of optimization speed for WLEDs.…”

Break the Interacting Bridge between Eu3+ Ions in the 3D Network Structure of CdMoO4: Eu3+ Bright Red Emission Phosphor

“…Phosphor-converted light-emitting diode (pc-LED) is the mainstream technology to produce solid-state illumination devices 3,4 . Nowadays, the commercial and excellent approach is the combination of cerium-doped yttrium aluminum garnet (YAG:Ce 3+ ) phosphor and blue InGaN LED chip which was first proposed in1997 5 .…”