Improving Color Quality of Nanowire White Light-Emitting Diodes with Mn4+ Doped Fluoride Nanosheets.

Thi Hong Quan Vu,Hieu Pham Trung Nguyen,Barsha Jain,Thi Tuyet Doan,Ravi Teja Velpula,Tung Cao Thanh Pham,Hoang-Duy Nguyen

doi:10.3390/mi12080965

Abstract

A two-dimensional nanostructured fluoride red-emitting phosphor with an excellent quantum yield of ~91% is studied for cost-effective and high-color quality nanowire white light-emitting diodes (WLEDs). K2TiF6:Mn4+ phosphors are synthesized via an emulsification method using surfactants as sodium dodecyl sulphonate and oleic acid. The K2TiF6:Mn4+ phosphors in ultra-thin and nanosheet crystals are observed via scanning electron microscopy and high-resolution transmission electron microscopy. The surfactants are found to play a key role in inhibition of KTFM crystal growth process and stabilization of Mn4+ ions doping into the K2TiF6 host. The prepared phosphors exhibited intensive red emission at approximately 632 nm and excellent thermal stability in the range of 300–500 K upon 460 nm light excitation. Moreover, the K2TiF6:Mn4+ nanosheets were integrated on InGaN/AlGaN nanowire WLEDs for color quality study. The results show that the nanowire WLEDs with red-emitting phosphor exhibit unprecedentedly high color rendering index ~96.4, and correlated color temperature ~4450 K.

Highlights

White light-emitting diodes (WLED), composed of yellow phosphor and blue-lightlight emitting diodes (LEDs), have been replacing traditional lights such as incandescent and fluorescent lamps for general lighting because of their highlight efficiency, long lifetime and energy saving [1,2,3].In order to improve the color rendering index (CRI) of white lightemitting diodes (WLEDs), red-emitting fluoride materials with high quantum yield area promising candidate, which is considered as a phosphor converted WLED or pc-WLED approach [4,5,6]
In order to improve the color rendering index (CRI) of WLED, red-emitting fluoride materials with high quantum yield area promising candidate, which is considered as a phosphor converted WLED or pc-WLED approach [4,5,6]
The utilization of red-emitting fluoride materials in nanowire LEDs offers a promising solution for achieving high power and high color quality nanowire WLEDs

Summary

Introduction

LED, have been replacing traditional lights such as incandescent and fluorescent lamps for general lighting because of their highlight efficiency, long lifetime and energy saving [1,2,3]. In order to improve the color rendering index (CRI) of WLED, red-emitting fluoride materials with high quantum yield area promising candidate, which is considered as a phosphor converted WLED or pc-WLED approach [4,5,6]. The utilization of red-emitting fluoride materials in nanowire LEDs offers a promising solution for achieving high power and high color quality nanowire WLEDs. Micromachines 2021, 12, 965. The synthesis of fluoride phosphors at room temperature is not complex, which is suitable for industry production Owing to their special structural, electronic and optical properties, nanocrystals offer new possibilities for applications in lighting, display, energy and environmental technologies [15]. The luminous efficacy and color rendering index (CRI) of white-light emitting diodes (LEDs) using thin-KTFM has been improved remarkably [19].

Chemicals

Characterization of Materials

Results and Discussion

Conclusions