Insertion of an Inorganic Barrier Layer as a Method of Improving the Performance of Quantum Dot Light-Emitting Diodes

Yoon, Sang Hyun; Gwak, Dham; Kim, Hong Hee; Woo, Hwi Je; Cho, Jin-Hee; Choi, Jin Woo; Choi, Won Kook; Song, Young Jae; Lee, Chang‐Lyoul; Park, Jong Hyun; Heo, Kwang; Choi, Young Jin

doi:10.1021/acsphotonics.8b01672

Cited by 24 publications

(30 citation statements)

References 30 publications

(54 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All devices display nearly saturated colors with the coordinate points approaching the boundary. [18] Notably, comparing with QLEDs prepared by solution processes previously reported, [6,[19][20][21][22][23] we demonstrated a feasible all-solution approach for achieving large-area high-performance QLEDs (Figure 5 i).…”

Section: Angewandte Chemiementioning

confidence: 55%

Direct Writing Large‐Area Multi‐Layer Ultrasmooth Films by an All‐Solution Process: Toward High‐Performance QLEDs

et al. 2020

View full text Add to dashboard Cite

With increasing the film area/layer, deteriorating in both smoothness and uniformity of thin-films frequently happen, which remains a barrier for making large-area quantum dot light-emitting diodes (QLEDs) by solution processes. Here, we demonstrated a facile all-solution process guided by the conical fiber array to write multi-layer ultrasmooth thin-films directly in centimeter scale. The side-by-side fibrous array helps to align surface tensions at the tri-phase contact line to facilitate large-area homogeneous deposition, which was verified by theoretical simulation. The Laplace pressure along individual conical fiber contributes to the steady liquid transfer. Thin-films with small roughness (< 2.03 nm) and large-area (2 2 cm 2) uniformity were prepared sequentially on the target substrate, leading to large-area highperformance QLEDs. The result offers new insights for fabricating large-area high-performance thin-film devices. Quantum dot light-emitting diodes (QLEDs) have attracted research attentions as the most promising nextgeneration display [1] and lighting [2] devices, because of the narrow spectral emission bandwidths, color tunability, and good photostability. [3] As a multi-layer thin-film device, sequential preparing functional layers on the target substrate were necessary, which have been normally realized by solution processes due to the mild conditions and easy operation. [4] For a high-performance QLED, high-quality thin-films with both small surface roughness and good uniformity are desirable for facilitating not only the charge transport within the film but the charge balance between neighboring layers. [5] So far, solution processes including spin coating, [6] inkjet printing, [7] and transfer printing [8] have been developed. However, these approaches suffered from the nonuniform deposition as the film area/layer increases, which remains a barrier for making large-area QLEDs. With increasing either the print area or the film layer, fluid

show abstract

Section: Angewandte Chemiementioning

confidence: 55%

Direct Writing Large‐Area Multi‐Layer Ultrasmooth Films by an All‐Solution Process: Toward High‐Performance QLEDs

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The use of ALD Al 2 O 3 has already been proven to be efficient as a diffusion barrier layer to prevent diffusion of species or charges in photonic devices. [ 40,41 ] In Figure 4b, the subthreshold currents are significantly reduced by more than 2 orders of magnitude thanks to the oxide. This phenomenon was observed on devices fabricated in the same batch of experiments, and was found to be reproducible by measuring several devices.…”

Section: Resultsmentioning

confidence: 99%

Halide Perovskite Precursors Dope PEDOT:PSS

Sandrez

Molenda

Guyot

et al. 2021

Adv Elect Materials

View full text Add to dashboard Cite

Halide perovskite semiconductors find use in a broad range of optoelectronic applications including photovoltaic solar cells and light‐emitting diodes. In such devices the semiconductor is sandwiched in between interlayers for charge transport, extraction, or injection. When it comes to hole transport layers, the conducting polymer PEDOT:PSS has become an ubiquitous material. The halide perovskite thin film is commonly obtained by crystallization of precursors using solution processing on top of PEDOT:PSS. It is demonstrated here that such a widely spread technique is actually affecting the electrical properties of the underlying conducting polymer. The halide perovskite layer and precursors are drastically doping the PEDOT:PSS, its conductivity being increased by two orders of magnitude from 0.2 to 20 S cm−1. The depth of penetration of halide dopants is determined to be higher than 150 nm, superior to the usual thickness of PEDOT:PSS films. This phenomenon has important impact on diode leakage currents, on emission patterns of perovskite LEDs and on overestimated photocurrent density in perovskite solar cells embedding the PEDOT:PSS interlayer.

show abstract

“…At the end, prospects of ALD applications on QDs based devices are discussed from the aspects of ALD materials, process parameters, in-situ characterization and device simulations. 86,88 CdSe/ZnS 61,66,77,87 ZnCdSSe/ZnS 68 CdSe@ZnS/ZnS 63 CdSe/CdS/ZnS 69,71 PbS 56,67,72,78,81,[83][84][85]89 PbSe 55,57,74,79,80 APbX3 60,65,70,75 Sphere 65 Film 57,58,66,69,70,73,74,77 FET 55,62,76,[78][79][80]83,86,88 Solar cell 56,82,84,85 Photodetector 67,…”

Section: (Iii) and (Iv)mentioning

confidence: 99%

“…The systematic study showed that an optimized 2 nm ALD-TiO 2 layer under 200 °C could promote solar cell efficiency by balancing the charge transfer. Additionally, Choi et al employed an inorganic barrier layer fabricated by ALD to improve the performance of QLED in both maximal luminance and current efficiency 61 . The Al 2 O 3 barrier layer could hinder the etching reaction with PEDOT:PSS and prevent metal ion diffusion from indium tin oxide into the emission layer sufficiently as shown in Fig.…”

Section: Interface Engineeringmentioning

confidence: 99%

Atomic layer deposition for quantum dots based devices

Zhou

Liu

Wen

et al. 2020

Opto-Electronic Advances

View full text Add to dashboard Cite

Quantum dots (QDs) are promising candidates for the next-generation optical and electronic devices due to the outstanding photoluminance efficiency, tunable bandgap and facile solution synthesis. Nevertheless, the limited optoelectronic performance and poor lifetime of QDs devices hinder their further applications. As a gas-phase surface treatment method, atomic layer deposition (ALD) has shown the potential in QDs surface modification and device construction owing to the atomic-level control and excellent uniformity/conformality. In this perspective, the attempts to utilize ALD techniques in QDs modification to improve the photoluminance efficiency, stability, carrier mobility, as well as interfacial carrier utilization are introduced. ALD proves to be successful in the photoluminance quantum yield (PLQY) enhancement due to the elimination of QDs surface dangling bonds and defects. The QDs stability and devices lifetime are improved greatly through the introduction of ALD barrier layers. Furthermore, the carrier transport is ameliorated efficiently by infilling interstitial spaces during ALD process. Attributed to the ultra-thin and dense coating on the interface, the improvement on optoelectronic performance is achieved. Finally, the challenges of ALD applications in QDs at present and several prospects including ALD process optimization, in-situ characterization and computational simulations are proposed.

show abstract

Insertion of an Inorganic Barrier Layer as a Method of Improving the Performance of Quantum Dot Light-Emitting Diodes

Cited by 24 publications

References 30 publications

Direct Writing Large‐Area Multi‐Layer Ultrasmooth Films by an All‐Solution Process: Toward High‐Performance QLEDs

Direct Writing Large‐Area Multi‐Layer Ultrasmooth Films by an All‐Solution Process: Toward High‐Performance QLEDs

Halide Perovskite Precursors Dope PEDOT:PSS

Atomic layer deposition for quantum dots based devices

Contact Info

Product

Resources

About