Highly Efficient and Thermally Stable QD-LEDs Based on Quantum Dots-SiO2-BN Nanoplate Assemblies

Yangyang Xie; Dongdong Yang; Lulu Zhang; Zizhen Zhang; Chong Geng; Chongyu Shen; Jay G Liu; Shu Xu; Wengang Bi

doi:10.1021/acsami.9b18500

Highly Efficient and Thermally Stable QD-LEDs Based on Quantum Dots-SiO₂-BN Nanoplate Assemblies

ACS Appl Mater Interfaces. 2020 Jan 8;12(1):1539-1548. doi: 10.1021/acsami.9b18500. Epub 2019 Dec 27.

Authors

Yangyang Xie¹, Dongdong Yang¹, Lulu Zhang¹, Zizhen Zhang¹, Chong Geng¹, Chongyu Shen², Jay G Liu², Shu Xu¹, Wengang Bi¹

Affiliations

¹ Tianjin Key Laboratory of Electronic Materials and Devices, School of Electronics and Information Engineering , Hebei University of Technology , 5340 Xiping Road , Beichen District, Tianjin 300401 , China.
² Shineon Co., Ltd. , Building 3, No. 58 Jinghai Road , BDA, Beijing 100176 , China.

PMID: 31834777
DOI: 10.1021/acsami.9b18500

Abstract

Silica encapsulation effectively elevates the resistance of quantum dots (QDs) against water and oxygen. However, QDs-SiO₂ composites present low thermal conductivity and strong thermal accumulation, leading to considerable fluorescence quenching of QDs in optoelectronic devices at high power. Here, a sandwich structural QDs-SiO₂-BN nanoplate assembly material (QDs-SiO₂-BNAs) is developed to reduce the thermal quenching and enhance the stability of QDs in LEDs. The QDs-SiO₂-BNAs is fabricated by embedding QDs-SiO₂ into the interlayer of layer-by-layer assembled BN nanoplates, and the BN nanoplates are pretreated by SiO₂ encapsulation to strengthen the interaction with QDs-SiO₂. This assembly structure endows the QDs with fast heat dissipation and double surface protection against air. The medium power QDs-converted LEDs (QD-LEDs) fabricated by direct on-chip packaging of the QDs-SiO₂-BNAs gain 44.2 °C temperature reduction at 0.5 W in comparison with conventional QD-LEDs. After aging, the resulting QD-LEDs present degradation of only 1.2% under sustained driving for 250 h. The QD-LEDs also pass the 1 week reliability test at 85 °C/85% RH with <±0.01 shift of the color coordinates, demonstrating the profound potential of the QDs-SiO₂-BNAs in LED lighting and display applications.

Keywords: assembly; boron nitride; light-emitting diodes; quantum dots; stability.