Cadmium‐Free InP/ZnSeS/ZnS Heterostructure‐Based Quantum Dot Light‐Emitting Diodes with a ZnMgO Electron Transport Layer and a Brightness of Over 10 000 cd m⁻²

Abstract

Cadmium-free thick-shelled InP/ZnSeS/ZnS quantum dot (QD) was synthesized using the heating-up approach. This quantum dots was used in inverted quantum dots light emitting diode (QLED) devices. The brightness of the inverted QLED device can reach a brightness of over 10 000 cd m , low turn-on voltage (2.2 V), and high power efficiency (4.32 lm W ).

High‐Efficiency Green InP Quantum Dot‐Based Electroluminescent Device Comprising Thick‐Shell Quantum Dots

“…The PL QYs then decreased by further increasing the shell thickness to form InP/GaP/ZnS//ZnS core/shell QDs owing to more or less formation of internal defects caused by dislocations and low‐angle grain boundaries. But, it is different from the previous thick‐shell ZnS growth onto CdSe or InP QDs that QYs rapidly decrease, the PL QY of InP/GaP/ZnS//ZnS core/shell QDs can maintain about 70% with emission peak at 527 nm and the FWHM is 58 nm after the fourth time growth of ZnS shell which is comparable to the record value of InP/ZnS QDs reported so far . We attributed this result to the thick ZnS shell which enables better surface passivation of QDs and GaP middle layer reduces internal defects of InP/GaP/ZnS core/shell QDs.…”

“…At present, the performance of InP core/shell QDs‐based LED remains far lower than those Cd‐ or Pb‐based ones, which is the bottleneck for further practical application of InP‐based devices. For an example, the highest brightness of the red and green InP‐based QLED reached 2849 cd m −2 (λ = 614 nm) and 10 490 cd m −2 (λ = 545 nm), respectively, and the highest EQEs were only about 2.5% (λ = 614 nm) and 3.46% (λ = 518 nm) . For the blue InP‐based QLED, there have been no record on the efficiency being reported so far.…”

81‐2: High Performance Red Cadmium‐free Inverted Quantum Dot Light Emitting Diodes

“…The other suitable contenders for Cadmium-free QDs are the InP based QDs because of their environmental friendliness. [4][5][6][7] The efficiency of InP based QLEDs is still inferior than that of cadmium-based QLEDs because of their low PLQY. Similarly, another important factors that limits device efficiency are the charge carrier injection barrier between transporting layers and QD based emissive layer (EML) as well as mobility of transporting layers.…”

Color‐by‐Blue QD‐Emissive LCD Enabled by Replacing RGB Color Filters with Narrow‐Band GR InP/ZnSeS/ZnS QD Films

“…However, InP‐based QDs should be able to match in terms of longevity, quantum efficiency, and the FWHM for further improvements in the near future. During the last five years, the photoluminescence (PL) performance capabilities of both InP‐based QDs have been markedly improved through the successful bandgap engineering of core/shell heterostructures and optimization of the process of synthesizing QDs using several precursor and capping material sources, as reported in several representative articles on the synthesis of highly efficient InP‐based QDs . With regard to the case of formation of highly efficient InP/ZnS QDs as described in the literature, there are two viable approaches to obtain high PL efficiency.…”