Highly efficient green InP-based quantum dot light-emitting diodes regulated by inner alloyed shell component

Abstract

InP-based quantum dot light-emitting diodes (QLEDs), as less toxic than Cd-free and Pb-free optoelectronic devices, have become the most promising benign alternatives for the next generation lighting and display. However, the development of green-emitting InP-based QLEDs still remains a great challenge to the environmental preparation of InP quantum dots (QDs) and superior device performance. Herein, we reported the highly efficient green-emitting InP-based QLEDs regulated by the inner alloyed shell components. Based on the environmental phosphorus tris(dimethylamino)phosphine ((DMA)3P), we obtained highly efficient InP-based QDs with the narrowest full width at half maximum (~35 nm) and highest quantum yield (~97%) by inserting the gradient inner shell layer ZnSexS1−x without further post-treatment. More importantly, we concretely discussed the effect and physical mechanism of ZnSexS1–x layer on the performance of QDs and QLEDs through the characterization of structure, luminescence, femtosecond transient absorption, and ultraviolet photoelectron spectroscopy. We demonstrated that the insert inner alloyed shell ZnSexS1−x provided bifunctionality, which diminished the interface defects upon balancing the lattice mismatch and tailored the energy levels of InP-based QDs which could promote the balanced carrier injection. The resulting QLEDs applying the InP/ZnSe0.7S0.3/ZnS QDs as an emitter layer exhibited a maximum external quantum efficiency of 15.2% with the electroluminescence peak of 532 nm, which was almost the highest record of InP-based pure green-emitting QLEDs. These results demonstrated the applicability and processability of inner shell component engineering in the preparation of high-quality InP-based QLEDs.

Automatic Illumination Control Method for Indoor Luminaires Based on Multichromatic Quantum Dot Light-Emitting Diodes

“…We select InP quantum dots (QDs) with different peak wavelengths as light conversion materials to produce white light, since InP QDs provide high stability, wide optical spectra for illumination, high wavelength tunability from blue color to near-infrared, and eco-friendliness in comparison with conventional cadmium-based QDs. The improvement of luminance, lifetime, quantum efficacy, and synthesizing methodology of InP QDs in recent studies point out the huge potential of InP QDs in illumination and displaying [ 21 , 22 ]. The synthesizing steps of InP QDs used in this study are given in [ 23 ].…”

Improving Performance of InP-Based Quantum Dot Light-Emitting Diodes by Controlling Defect States of the ZnO Electron Transport Layer

“…Indium phosphide (InP)-based quantum dot light-emitting diodes (QLEDs) are considered the most promising display and lighting technology due to their high color purity, low toxicity, and tunable spectrum. − In recent years, with the development of InP-based quantum dot (QD) synthesis technology and the design and optimization of the device structure, the performance of QLEDs based on InP QDs has been greatly improved. − However, the performance of InP-based QLEDs still lags behind that of Cd- and Pb-based QLEDs. Further understanding the working mechanism of InP-based QLEDs and developing the related fabrication technologies are crucial for obtaining high-performance devices.…”

High-Efficiency Pure-Red Perovskite Quantum-Dot Light-Emitting Diodes

“…As shown in Figure a, the peaks of the EL spectra of the PeLED based on the SQD shift slightly with increasing voltage, indicating good spectral stability, but its EL spectra show a large red-shift (from 642 to 655 nm) and broadening (from 34 to 47 nm), compared to the PL spectrum of the SQD in solution. This is presumably caused by the FRET and the electric field-induced Stark effect . However, compared to the PL spectrum of the SQD in solution, the fwhm and peak of the SQD film show almost no change (Figure S12a).…”

“…This is presumably caused by the FRET and the electric field-induced Stark effect. 38 However, compared to the PL spectrum of the SQD in solution, the fwhm and peak of the SQD film show almost no change (Figure S12a). Therefore, FRET is not responsible for the red-shift and broadening of the EL spectrum.…”