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(a) Schematic diagram of tandem OLED based on the PEDOT:PSS/n-PEODT:PSS/ZnO/PEIE ICL. (b) Normalized EL spectra and (c) CE-J characteristics of green single and tandem devices. (d) Normalized EL spectra and (e) CE-J characteristics of bule/red single devices and white tandem device. Reproduced with permission from ref. [69]. Copyright 2015, WILEY.
Source publication
Solution processes have promising advantages of low manufacturing cost and large-scale production, potentially applied for the fabrication of organic and quantum dot light-emitting diodes (OLEDs and QLEDs). To meet the expected lifespan of OLEDs/QLEDs in practical display and lighting applications, tandem architecture by connecting multiple light-e...
Contexts in source publication
Context 1
... to direct contact, the degradation of ZnO by the adjacent acid PEDOT:PSS remains inevitable. In this regard, Chiba et al. proposed a neutralized PEDOT:PSS (n-PE-DOT:PSS) layer inserted between acidic PEDOT:PSS and ZnO nanoparticles (Figure 8a), thereby preventing direct contact between the two [69]. The neutralized PEDOT:PSS was achieved by the facile addition of NaOH. ...
Context 2
... multilayer structure PEDOT:PSS/n-PEODT:PSS/ZnO/PEIE also showed strong resistance against common organic solvents such as toluene, p-xylene, and tetrahydrofuran. A twofold increase in luminance and voltage is observed when the LEUs are stacked (Figure 8c,e). The CE of the tandem-OLED was 92.8 cd/A at 1000 cd/m 2 , equal to the sum of the corresponding efficiencies of the components first-LEU (26.7 cd/A) and second-LEU (49.4 cd/A). ...
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Quantum dot (QD) semiconductor nanocrystals are being considered a competitive contender as the emitting materials of next-generation light-emitting diodes (LEDS) in lighting and display applications. One of ways to improve the performance of a QDs-based device is to develop/modify the layers in the multi-layer structure of the device to have good...
Citations
... In recent years, the research interest in quantum dots light emitting diodes (QLED) has been spurred by their high color purity [1,2], high brightness [3] and low energy consumption [4]. These characteristics give QLED an edge over other light emitting devices (LED) in the field of short-wavelength light emitting. ...
Short-wavelength light-emitting diodes (SWLED) have received exclusive attention due to their widespread applications. Zinc oxide (ZnO) quantum dots (QDs) are considered ideal materials for SWLED, and they have been used in building ZnO quantum dot light emitting diodes (QLED). However, the electroluminescence (EL) performance of the ZnO QLED is still low. Herein, Aluminum-doped ZnO/ Silver nanowires/Aluminum-doped ZnO (AZO/Ag NWs/AZO) composite film is prepared to serve as the cathode of ZnO QLED, resulting in an enhancement of the near-UV emission of the device by about 81%. Time-resolved and temperature-dependent spectroscopy analysis shows that the observed EL enhancement is from the improved spontaneous emission rate and internal quantum efficiency (IQE) by the resonance coupling between ZnO QDs excitons and Ag NWs surface plasmon. The research may impact applications of ZnO QLED in the field of short-wavelength luminescence.
... In recent years, the solid-state luminescence of organic materials has drawn much attention due to the rapid development of optoelectronic devices and applications such as organic light emitting diodes (OLEDs) [1][2][3], optical sensors [4], stimuli responses, and anti-counterfeit printing [5]. However, many organic materials exhibit intense fluorescence emission in dilute solutions, while the emission is severely quenched in the aggregate state. ...
... o-DBCNPy was obtained as a bright yellow solid from the starting material 4-(di-p-tolylamino)benzaldehyde and 2-(pyridin-2-yl)acetonitrile (yield: 71%). 1 Synthesis and characterization of (Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-3yl)acrylonitrile (m-DBCNPy). m-DBCNPy was acquired as a pale yellow solid from 4-(di-ptolylamino)benzaldehyde and 3-(pyridin-2-yl)acetonitrile (yield: 66%). 1 13 Synthesis and characterization of (Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-4yl)acrylonitrile (p-DBCNPy). ...
... m-DBCNPy was acquired as a pale yellow solid from 4-(di-ptolylamino)benzaldehyde and 3-(pyridin-2-yl)acetonitrile (yield: 66%). 1 13 Synthesis and characterization of (Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-4yl)acrylonitrile (p-DBCNPy). p-DBCNPy was obtained as a bright yellow crystal from 4-(di-p-tolylamino)benzaldehyde and 4-(pyridin-2-yl)acetonitrile (yield: 75%). ...
A series of aggregation-induced emission (AIE)-featured phenylmethylene pyridineacetonitrile derivatives named o-DBCNPy ((Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-2-yl)acrylonitrile), m-DBCNPy ((Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-3-yl)acrylonitrile), and p-DBCNPy ((Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-4-yl)acrylonitrile) have been synthesized by tuning the substitution position of the pyridine ring. The linkage manner of the pyridine ring had influences on the molecular configuration and conjugation, thus leading to different photophysical properties. The absorption and fluorescence emission peak showed a bathochromic shift when the linking position of the pyridine ring changed from the meta to the ortho and para position. Meanwhile, o-DBCNPy exhibited the highest fluorescence quantum yield of 0.81 and the longest fluorescence lifetime of 7.96 ns as a neat film among all three isomers. Moreover, non-doped organic light-emitting diodes (OLEDs) were assembled in which the molecules acted as the light-emitting layer. Due to the relatively prominent emission properties, the electroluminescence (EL) performance of the o-DBCNPy-based OLED was superior to those of the devices based on the other two isomers with an external quantum efficiency (EQE) of 4.31%. The results indicate that delicate molecular modulation of AIE molecules could endow them with improved photophysical properties, making them potential candidates for organic photoelectronic devices.
Organic light‐emitting diodes in tandem structures (TOLEDs) have long been an effective strategy to realize multifold increased electroluminescence (EL) efficiency relative to the single‐unit OLEDs, making TOLEDs promising candidates for lighting and display applications. Benefitted from the development of organic emitters, hybrid tandem OLEDs (HTOLEDs) composing two or more types of OLED emitters (phosphorescence, fluorescence, and thermally‐activated delayed fluorescence (TADF)) are developed. The different energy conversion processes of these emitters can facilitate manipulated exciton distribution inside the device, leading to enhanced device performance. On the other hand, different emission technologies can also be integrated to form another kind of hybrid tandem light‐emitting diodes (HTLED) thanks to the compatibility of OLEDs with quantum dot LEDs (QLEDs) and perovskite LEDs (PeLEDs). In this review, the performance of different types of HTOLEDs and HTLEDs is comprehensively reviewed particularly focusing on the exciton regulations and manipulation of emission spectra in the sub‐units, aiming to provide guidelines for the EL performance optimization of HTOLEDs.
