Iodide capped PbS/CdS core-shell quantum dots for efficient long-wavelength near-infrared light-emitting diodes

Xuyong Yang,Fuqiang Ren,Yue Wang,Tao Ding,Xia Wei Sun,Dongling Ma,Handong Sun

doi:10.1038/s41598-017-15244-5

Abstract

PbS based quantum dots (QDs) have been studied in great detail for potential applications in electroluminescent devices operating at wavelengths important for telecommunications (1.3–1.6 μm). Despite the recent advances in field of quantum dot light-emitting diode (QLED), further improvements in near-infrared (NIR) emitting device performance are still necessary for the widespread use and commercialization of NIR emitting QLED technology. Here, we report a high-performance 1.51-μm emitting QLED with inverted organic–inorganic hybrid device architecture and PbS/CdS core-shell structured quantum dots as emitter. The resultant QLEDs show a record device performance for the QLEDs in 1.5 μm emission window, with a maximum radiance of 6.04 Wsr−1 m−2 and peak external quantum efficiency (EQE) of 4.12%, respectively.

Highlights

Quantum dots (QDs) based light-emitting diodes (QLEDs) have attracted increasing interest due to their narrow emission linewidth, tunable emission spectral window as well as facile solution-processibility[1,2,3,4]
To achieve high-performance quantum dot light-emitting diode (QLED), it is necessary to start with a quantum dot emitter with a high quantum yield for electroluminescence where the excited state is generated by electron-hole recombination
The PbS/CdS core-shell quantum dots (QDs) with a ~1481 nm peak emission wavelength we used were prepared by a microwave-assisted cation exchange approach (Supporting Information Fig. S1)

Summary

Introduction

Quantum dots (QDs) based light-emitting diodes (QLEDs) have attracted increasing interest due to their narrow emission linewidth, tunable emission spectral window as well as facile solution-processibility[1,2,3,4]. Supran et al reported short-wavelength NIR QLEDs with λ > 1 μm using core-shell structured PbS/CdS QDs15. Previous efforts at developing NIR emitting QLEDs have demonstrated only limited success due to the low emission efficiency and insulating surface ligands of QDs as well as the poor carrier mobility of organic charge transport materials.

Results

Conclusion