Browse
Submit Data
Databases
API
Help

Dataset Information

26 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Color-Stable Blue Light-Emitting Diodes Enabled by Effective Passivation of Mixed Halide Perovskites.

ABSTRACT: Bandgap tuning through mixing halide anions is one of the most attractive features for metal halide perovskites. However, mixed halide perovskites usually suffer from phase segregation under electrical biases. Herein, we obtain high-performance and color-stable blue perovskite LEDs (PeLEDs) based on mixed bromide/chloride three-dimensional (3D) structures. We demonstrate that the color instability of CsPb(Br_1-xCl_x)₃ PeLEDs results from surface defects at perovskite grain boundaries. By effective defect passivation, we achieve color-stable blue electroluminescence from CsPb(Br_1-xCl_x)₃ PeLEDs, with maximum external quantum efficiencies of up to 4.5% and high luminance of up to 5351 cd m^-2 in the sky-blue region (489 nm). Our work provides new insights into the color instability issue of mixed halide perovskites and can spur new development of high-performance and color-stable blue PeLEDs.

SUBMITTER: Yu H

PROVIDER: S-EPMC8273884 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Mixed halide perovskites for spectrally stable and high-efficiency blue light-emitting diodes.

Project description:Bright and efficient blue emission is key to further development of metal halide perovskite light-emitting diodes. Although modifying bromide/chloride composition is straightforward to achieve blue emission, practical implementation of this strategy has been challenging due to poor colour stability and severe photoluminescence quenching. Both detrimental effects become increasingly prominent in perovskites with the high chloride content needed to produce blue emission. Here, we solve these critical challenges in mixed halide perovskites and demonstrate spectrally stable blue perovskite light-emitting diodes over a wide range of emission wavelengths from 490 to 451 nanometres. The emission colour is directly tuned by modifying the halide composition. Particularly, our blue and deep-blue light-emitting diodes based on three-dimensional perovskites show high EQE values of 11.0% and 5.5% with emission peaks at 477 and 467 nm, respectively. These achievements are enabled by a vapour-assisted crystallization technique, which largely mitigates local compositional heterogeneity and ion migration.

| S-EPMC7806600 | biostudies-literature

Color-stable highly luminescent sky-blue perovskite light-emitting diodes.

Project description:Perovskite light-emitting diodes (PeLEDs) have shown excellent performance in the green and near-infrared spectral regions, with high color purity, efficiency, and brightness. In order to shift the emission wavelength to the blue, compositional engineering (anion mixing) and quantum-confinement engineering (reduced-dimensionality) have been employed. Unfortunately, LED emission profiles shift with increasing driving voltages due to either phase separation or the coexistence of multiple crystal domains. Here we report color-stable sky-blue PeLEDs achieved by enhancing the phase monodispersity of quasi-2D perovskite thin films. We selected cation combinations that modulate the crystallization and layer thickness distribution of the domains. The perovskite films show a record photoluminescence quantum yield of 88% at 477?nm. The corresponding PeLEDs exhibit stable sky-blue emission under high operation voltages. A maximum luminance of 2480?cd?m-2 at 490?nm is achieved, fully one order of magnitude higher than the previous record for quasi-2D blue PeLEDs.

| S-EPMC6117319 | biostudies-literature

Color-Stable White Organic Light-Emitting Diodes Utilizing a Blue-Emitting Electron-Transport Layer.

Project description:We have fabricated efficient and color-stable white organic light-emitting diodes (WOLEDs) based on a simple double-layer device structure consisting of a blue-emitting oligoquinoline electron-transport layer and a poly(N-vinyl carbazole) layer doped with phosphorescent green and red iridium emitters. Pure white color with the CIE coordinates from (0.30, 0.31) to (0.34, 0.37) in the whole operating bias voltage range and luminous efficiency higher than 7 cd/A at a brightness up to 12?000 cd/m2 was achieved. These results demonstrate a new strategy to realizing easily processable, highly efficient, and color-stable WOLEDs with a simple structure.

| S-EPMC6645075 | biostudies-literature

Spectrally Stable Blue Light-Emitting Diodes Based on All-Inorganic Halide Perovskite Films.

Project description:Substantial progress has been made in perovskite light-emitting diodes (PeLEDs), but the fabrication of high-performance blue PeLEDs still remains a challenge due to its low efficiency, spectral instability and short operational lifetime. How to produce an efficient and stable blue PeLED is the key to realizing the application of PeLEDs in full-color displays. We herein report a blue PeLED usint the ligand-assisted reprecipitation method, in which phenylethylammonium bromide (PEABr) was used as ligands, and chloroform was used as anti-solvent to prepare blue perovskite nanocrystal films. By increasing the PEABr content from 40% to 100% (The ratio of x% PEABr refers to the molar ratio between PEABr and PbBr2), the film quality is highly improved, and the emission exhibits a blue shift. Introducing a poly(9-vinylcarbazole) (PVK) hole transport layer into the device, the PVK layer can not only achieve efficient hole injection, but can also isolate the PEDOT: PSS layer to inhibit the non-radiative recombination of metal halide luminescence layer, reduce surface ion defects and successfully inhibit halide atom migration. Finally, the PeLED presents a stable electroluminescence under different driving voltages without any red shift.

| S-EPMC9457983 | biostudies-literature

Spectra stable blue perovskite light-emitting diodes.

Project description:Device performance and in particular device stability for blue perovskite light-emitting diodes (PeLEDs) remain considerable challenges for the whole community. In this manuscript, we conceive an approach by tuning the 'A-site' cation composition of perovskites to develop blue-emitters. We herein report a Rubidium-Cesium alloyed, quasi-two-dimensional perovskite and demonstrate its great potential for pure-blue PeLED applications. Composition engineering and in-situ passivation are conducted to further improve the material's emission property and stabilities. Consequently, we get a prominent film photoluminescence quantum yield of around 82% under low excitation density. Encouraged by these findings, we finally achieve a spectra-stable blue PeLED with the peak external quantum efficiency of 1.35% and a half-lifetime of 14.5 min, representing the most efficient and stable pure-blue PeLEDs reported so far. The strategy is also demonstrated to be able to generate efficient perovskite blue emitters and PeLEDs in the whole blue spectral region (from 454 to 492 nm).

| S-EPMC6478869 | biostudies-literature

Efficient Quantum Dot Light-Emitting Diodes Based on Trioctylphosphine Oxide-Passivated Organometallic Halide Perovskites.

Project description:Metal halide perovskite quantum dots (QDs) have attracted significant research interest in the next-generation display and solid illumination fields due to their excellent optical properties of high photoluminescence quantum efficiency, high color purity, obvious quantum confinement effect, and large exciton binding energy. A large amount of surface defects and nonradiative recombination induced by these defects are considered as major problems to be resolved urgently for practical applications of perovskite QDs in high-efficiency light-emitting diodes (LEDs). Herein, we report an efficient passivation of green perovskite QD CH3NH3PbBr3 with trioctylphosphine oxide (TOPO). By simply adding the appropriate amount of TOPO into the nonpolar toluene solvent to synthesize CH3NH3PbBr3 QDs, the surface defects of these as-synthesized perovskite QDs are obviously reduced, along with an increased photoluminescence lifetime and suppressed nonradiative recombination. Further investigation indicates that electronegative oxygen from TOPO (Lewis base) bonds with uncoordinated Pb2+ ions and labile lead atoms in perovskite. With TOPO passivation, the green perovskite QD LEDs based on CH3NH3PbBr3 show significant performance improvement factors of 93.5, 161.1, and 168.9% for luminance, current efficiency, and external quantum efficiency, respectively, reaching values of 1635 cd m-2, 5.51 cd A-1, and 1.64% in the eventual optimized devices. Furthermore, the presence of TOPO dramatically improves stabilities of CH3NH3PbBr3 QDs and related devices. Our work provides a robust platform for the fabrication of low-defect-density perovskite QDs and efficient, stable perovskite QD LEDs.

| S-EPMC6648744 | biostudies-literature

Color-pure red light-emitting diodes based on two-dimensional lead-free perovskites.

Project description:It remains a central challenge to the information display community to develop red light-emitting diodes (LEDs) that meet demanding color coordinate requirements for wide color gamut displays. Here, we report high-efficiency, lead-free (PEA)2SnI4 perovskite LEDs (PeLEDs) with color coordinates (0.708, 0.292) that fulfill the Rec. 2100 specification for red emitters. Using valeric acid (VA)-which we show to be strongly coordinated to Sn2+-we slow the crystallization rate of the perovskite, improving the film morphology. The incorporation of VA also protects tin from undesired oxidation during the film-forming process. The improved films and the reduced Sn4+ content enable PeLEDs with an external quantum efficiency of 5% and an operating half-life exceeding 15 hours at an initial brightness of 20 cd/m2 This work illustrates the potential of Cd- and Pb-free PeLEDs for display technology.

| S-EPMC7556835 | biostudies-literature

Zn-Alloyed All-Inorganic Halide Perovskite-Based White Light-Emitting Diodes with Superior Color Quality.

Project description:Recently, lead halide perovskite nanocrystals (NCs) have gained tremendous attention in optoelectronic devices due to their excellent optical properties. However, the toxicity of lead limits their practical applications. Here, the synthesis of Zn2+-alloyed CsZnxPb1-xX3 (up to 15%) NCs is reported to achieve lead-reduced white light-emitting diodes (WLEDs). The incorporation of Zn2+ into CsPbX3 host NCs results in a lattice contraction, without altering the structure and morphology, which has a direct effect on the optical properties. The blue-shifts in the photoluminescence emission and increase in bandgap is observed while retaining high photoluminescence quantum yield. Then by engineering the different compositions of halides for 15% Zn2+-alloyed CsZnxPb1-xX3 NCs, tunable emission (411-636?nm) is obtained. Notably, the WLEDs are experimentally demonstrated employing the lead-reduced NCs (blue, green, yellow, and red). By varying the ratios of the amount of NCs, white lights with a tunable correlated-color temperature (2218-8335?K), an exemplary color-rendering index (up to 93) and high luminous efficacy of radiation (268-318?lm·W-1) are obtained. Best of our knowledge, these are superior to other reported WLEDs based on CsPbX3 NCs doped with transition metal ions. This work places the halide perovskite NCs one-step closer in designing the environmentally benign and energy-efficient WLEDs.

| S-EPMC6901607 | biostudies-literature

Electroluminescent Warm White Light-Emitting Diodes Based on Passivation Enabled Bright Red Bandgap Emission Carbon Quantum Dots.

Project description:The development of efficient red bandgap emission carbon quantum dots (CQDs) for realizing high-performance electroluminescent warm white light-emitting diodes (warm-WLEDs) represents a grand challenge. Here, the synthesis of three red-emissive electron-donating group passivated CQDs (R-EGP-CQDs): R-EGP-CQDs-NMe2, -NEt2, and -NPr2 is reported. The R-EGP-CQDs, well soluble in common organic solvents, display bright red bandgap emission at 637, 642, and 645 nm, respectively, reaching the highest photoluminescence quantum yield (QY) up to 86.0% in ethanol. Theoretical investigations reveal that the red bandgap emission originates from the rigid π-conjugated skeleton structure, and the -NMe2, -NEt2, and -NPr2 passivation plays a key role in inducing charge transfer excited state in the π-conjugated structure to afford the high QY. Solution-processed electroluminescent warm-WLEDs based on the R-EGP-CQDs-NMe2, -NEt2, and -NPr2 display voltage-stable warm white spectra with a maximum luminance of 5248-5909 cd m-2 and a current efficiency of 3.65-3.85 cd A-1. The warm-WLEDs also show good long-term operational stability (L/L 0 > 80% after 50 h operation, L 0: 1000 cd m-2). The electron-donating group passivation strategy opens a new avenue to realizing efficient red bandgap emission CQDs and developing high-performance electroluminescent warm-WLEDs.

| S-EPMC6662328 | biostudies-literature

Identifying and Reducing Interfacial Losses to Enhance Color-Pure Electroluminescence in Blue-Emitting Perovskite Nanoplatelet Light-Emitting Diodes.

Project description:Perovskite nanoplatelets (NPls) hold promise for light-emitting applications, having achieved photoluminescence quantum efficiencies approaching unity in the blue wavelength range, where other metal-halide perovskites have typically been ineffective. However, the external quantum efficiencies (EQEs) of blue-emitting NPl light-emitting diodes (LEDs) have reached only 0.12%. In this work, we show that NPl LEDs are primarily limited by a poor electronic interface between the emitter and hole injector. We show that the NPls have remarkably deep ionization potentials (≥6.5 eV), leading to large barriers for hole injection, as well as substantial nonradiative decay at the NPl/hole-injector interface. We find that an effective way to reduce these nonradiative losses is by using poly(triarylamine) interlayers, which lead to an increase in the EQE of the blue (464 nm emission wavelength) and sky-blue (489 nm emission wavelength) LEDs to 0.3% and 0.55%, respectively. Our work also identifies the key challenges for further efficiency increases.

| S-EPMC6516044 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data