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High‐Efficiency Green InP Quantum Dot‐Based Electroluminescent Device Comprising Thick‐Shell Quantum Dots
Author(s) -
Zhang Han,
Hu Ning,
Zeng Zaiping,
Lin Qingli,
Zhang Fengjuan,
Tang Aiwei,
Jia Yu,
Li Lin Song,
Shen Huaibin,
Teng Feng,
Du Zuliang
Publication year - 2019
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.201801602
Subject(s) - quantum dot , indium phosphide , materials science , optoelectronics , electroluminescence , light emitting diode , indium , fabrication , quantum efficiency , diode , nanotechnology , gallium arsenide , layer (electronics) , medicine , alternative medicine , pathology
Indium phosphide (InP) core/shell quantum dots (QDs) without intrinsic toxicity have shown great potential to replace the widely applied cadmium‐containing QDs in next‐generation commercial display and lighting applications. However, it remains challenging to synthesize InP core/shell QDs with high quantum yields (QYs), uniform particle size, and simultaneously thicker shell thickness to reduce nonradiative Förster resonant energy transfer (FRET). Here, thick InP‐Based QLEDs shell InP/GaP/ZnS//ZnS core/shell QDs with high stability, high QY (≈70%), and large particle size (7.2 ± 1.3 nm) are successfully synthesized through extending the growth time of shell materials along with the timely replenishment of shelling precursor. The existence of GaP interface layer minimizes the lattice mismatch and reduces interfacial defects. While thick ZnS shell, which suppresses the FRET between closely packed QDs, ensures high PL QY and stability. The robustness of such properties is demonstrated by the fabrication of green electroluminescent LEDs based on InP core/shell QDs with the peak external quantum efficiency and current efficiency of 6.3% and 13.7 cd A −1 , respectively, which are the most‐efficient InP‐based green quantum dot light‐emitting diodes (QLEDs) till now. This work provides an effective strategy to further improve heavy‐metal‐free QLED performance and moves a significant step toward the commercial application of InP‐based electroluminescent device.