scholarly journals Improvement of photoluminescence intensity and film morphology of perovskite by Ionic liquids additive

2021 ◽  
Vol 257 ◽  
pp. 03066
Author(s):  
Dongyang Shen ◽  
Chengzhao Luo ◽  
Ronghong Zheng ◽  
Qinyi Li ◽  
Yu Chen
Keyword(s):  
Ionic Liquid ◽  
Radiative Recombination ◽  
Photoluminescence Intensity ◽  
Light Emitting ◽  
The Past ◽  
Perovskite Materials ◽  
New Strategy ◽  
Halide Perovskites ◽  
Significant Attention ◽  
Long Chain

Metal halide perovskites have received much attention for their application in light-emitting diodes (LEDs) and solar cells in the past several years. Among them, 2D and quasi-2D perovskite with organic long-chain cations introduced have drawn significant attention. However, while improving wet and thermal stability, as the grain size becomes smaller, more defects introduced at the grain boundary and surface, resulting in the increase of non-radiative recombination is becoming the main problem which should be faced by 2D/quasi-2D perovskite materials. Here, we report a new strategy employing ionic liquid named 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(EMB).By adding a small amount of ionic liquid to the precursor, the defect was effectively passivated and the photoluminescence intensity was increased by 11 times and the fluorescent lifetime was increased by about 1.5 times. The flatness of the prepared perovskite thin films has also been effectively improved.

scholarly journals Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites

2016 ◽  
Vol 2 (10) ◽  
pp. e1601156 ◽  
Author(s):  
M. Ibrahim Dar ◽  
Gwénolé Jacopin ◽  
Simone Meloni ◽  
Alessandro Mattoni ◽  
Neha Arora ◽  
...  
Keyword(s):  
Density Functional ◽  
Valence Band Maximum ◽  
Dual Emission ◽  
Time Resolved ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Perovskite Materials ◽  
Halide Perovskites ◽  
Dynamics Simulations ◽  
Increasing Temperature

Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift of the bandgap and dual emission in perovskites is still lacking. In this direction, we investigated the extraordinary photoluminescence behavior of three representatives of this important class of photonic materials, that is, CH3NH3PbI3, CH3NH3PbBr3, and CH(NH2)2PbBr3, which emerged from our thorough studies of the effects of temperature on their bandgap and emission decay dynamics using time-integrated and time-resolved photoluminescence spectroscopy. The low-temperature (<100 K) photoluminescence of CH3NH3PbI3and CH3NH3PbBr3reveals two distinct emission peaks, whereas that of CH(NH2)2PbBr3shows a single emission peak. Furthermore, irrespective of perovskite composition, the bandgap exhibits an unusual blueshift by raising the temperature from 15 to 300 K. Density functional theory and classical molecular dynamics simulations allow for assigning the additional photoluminescence peak to the presence of molecularly disordered orthorhombic domains and also rationalize that the unusual blueshift of the bandgap with increasing temperature is due to the stabilization of the valence band maximum. Our findings provide new insights into the salient emission properties of perovskite materials, which define their performance in solar cells and light-emitting devices.

scholarly journals Advances Achieved by Ionic-Liquid-Based Materials as Alternative Supports and Purification Platforms for Proteins and Enzymes

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2542
Author(s):  
Rui M. F. Bento ◽  
Catarina A. S. Almeida ◽  
Márcia C. Neves ◽  
Ana P. M. Tavares ◽  
Mara G. Freire
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Pharmaceutical Sciences ◽  
Development Phase ◽  
Preparative Liquid Chromatography ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Properties Of Materials ◽  
Supported Ionic Liquids ◽  
Significant Attention

Ionic liquids (ILs) have been applied in several fields in which enzymes and proteins play a noteworthy role, for instance in biorefinery, biotechnology, and pharmaceutical sciences, among others. Despite their use as solvents and co-solvents, their combination with materials for protein- and enzyme-based applications has raised significant attention in the past few years. Among them, significant advances were brought by supported ionic liquids (SILs), in which ILs are introduced to modify the surface and properties of materials, e.g., as ligands when covalently bond or when physiosorbed. SILs have been mainly investigated as alternative supports for enzymes in biocatalysis and as new supports in preparative liquid chromatography for the purification of high-value proteins and enzymes. In this manuscript, we provide an overview on the most relevant advances by using SILs as supports for enzymes and as purification platforms for a variety of proteins and enzymes. The interaction mechanisms occurring between proteins and SILs/ILs are highlighted, allowing the design of efficient processes involving SILs. The work developed is discussed in light of the respective development phase and innovation level of the applied technologies. Advantages and disadvantages are identified, as well as the missing links to pave their use in relevant applications.

Engineering Electrodes and Metal Halide Perovskite Materials for Flexible/Stretchable Perovskite Solar Cells and Light-Emitting Diodes

2021 ◽  
Author(s):  
Kyung-Geun Lim ◽  
Tae-Hee Han ◽  
Tae-Woo Lee
Keyword(s):  
Solar Cells ◽  
Electronic Devices ◽  
Perovskite Solar Cells ◽  
Metal Halide ◽  
Inorganic Hybrid ◽  
Light Emitting ◽  
Perovskite Materials ◽  
Metal Halide Perovskite ◽  
Halide Perovskites ◽  
Halide Perovskite

Organic-inorganic hybrid metal halide perovskites have excellent optoelectronic properties and are soft and resilient; therefore, they are appropriate for use in flexible and stretchable electronic devices. Commercialization of these perovskite...

scholarly journals Germanium-lead perovskite light-emitting diodes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dexin Yang ◽  
Guoling Zhang ◽  
Runchen Lai ◽  
Yao Cheng ◽  
Yaxiao Lian ◽  
...  
Keyword(s):  
Environmental Impact ◽  
High Performance ◽  
High Brightness ◽  
Light Emitting ◽  
Perovskite Materials ◽  
Promising Solution ◽  
Halide Perovskites ◽  
Reduced Toxicity ◽  
Photovoltaic Solar Cells ◽  
Lead Halide

AbstractReducing environmental impact is a key challenge for perovskite optoelectronics, as most high-performance devices are based on potentially toxic lead-halide perovskites. For photovoltaic solar cells, tin-lead (Sn–Pb) perovskite materials provide a promising solution for reducing toxicity. However, Sn–Pb perovskites typically exhibit low luminescence efficiencies, and are not ideal for light-emitting applications. Here we demonstrate highly luminescent germanium-lead (Ge–Pb) perovskite films with photoluminescence quantum efficiencies (PLQEs) of up to ~71%, showing a considerable relative improvement of ~34% over similarly prepared Ge-free, Pb-based perovskite films. In our initial demonstration of Ge–Pb perovskite LEDs, we achieve external quantum efficiencies (EQEs) of up to ~13.1% at high brightness (~1900 cd m−2), a step forward for reduced-toxicity perovskite LEDs. Our findings offer a new solution for developing eco-friendly light-emitting technologies based on perovskite semiconductors.

scholarly journals 2D/3D Halide Perovskites for Optoelectronic Devices

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiang Chen ◽  
Hai Zhou ◽  
Hao Wang
Keyword(s):  
Performance Enhancement ◽  
Rapid Development ◽  
Three Dimensional ◽  
Light Emitting ◽  
The Past ◽  
Carbon Chains ◽  
Aliphatic Carbon ◽  
Halide Perovskites ◽  
Future Direction ◽  
Perovskite Lattice

The traditional three-dimensional (3D) halide perovskites (HPs) have experienced rapid development due to their highly power conversion efficiency (PCE). However, the instability of 3D perovskite on humidity and UV irradiation blocks their commercialization. In the past few years, two-dimensional (2D) halide perovskites attract much attention because they behave better stability due to the water resistance of the aliphatic carbon chains in the 2D perovskite lattice. In this review, we categorize the 2D/3D perovskites based on the applications [i.e., solar cells (SCs), light-emitting diodes (LEDs) and photodetectors (PDs)]. We further discuss the recent efforts in the performance enhancement of the 2D/3D perovskite-based devices. However, there are still some difficulties before 2D/3D HPs is fully commercialized. We will provide some scientific and technical challenges and prospects in the article to point out the future direction.

scholarly journals Control of spontaneous emission rate in lead halide perovskite film on hyperbolic metamaterial

2021 ◽  
Vol 2015 (1) ◽  
pp. 012153
Author(s):  
Pavel Tonkaev ◽  
Sergey Makarov
Keyword(s):  
Radiative Recombination ◽  
Emission Rate ◽  
Optoelectronic Devices ◽  
Spontaneous Emission Rate ◽  
Hyperbolic Metamaterials ◽  
Light Emitting ◽  
Hyperbolic Metamaterial ◽  
Light Emitting Devices ◽  
Halide Perovskites ◽  
Lead Halide

Abstract Hyperbolic metamaterials represent a class of nanophotonic architectures with the possibility of controlling density of optical states. Due to this property, hyperbolic metamaterials can be employed as meta-electrodes in optoelectronic devices. On the other hand, lead halide perovskites have several promising properties for application in light-emitting devices. Moreover, a perovskite film is easily deposited on a hyperbolic metamaterial surface. Here, we theoretically show how to accelerate radiative recombination in a perovskite film with a hyperbolic metamaterial. This effect can be applied in light-emitting devices, where radiative recombination is extremely important.

scholarly journals Bandgap tuning strategy by cations and halide ions of lead halide perovskites learned from machine learning

RSC Advances ◽  
2021 ◽  
Vol 11 (26) ◽  
pp. 15688-15694
Author(s):  
Yaoyao Li ◽  
Yao Lu ◽  
Xiaomin Huo ◽  
Dong Wei ◽  
Juan Meng ◽  
...  
Keyword(s):  
Perovskite Solar Cells ◽  
Halide Ions ◽  
Bandgap Engineering ◽  
Light Emitting ◽  
Perovskite Materials ◽  
Color Tunable ◽  
Halide Perovskites ◽  
Tuning Strategy ◽  
Bandgap Tuning ◽  
Lead Halide

Bandgap engineering of lead halide perovskite materials is critical to achieve highly efficient and stable perovskite solar cells and color tunable stable perovskite light-emitting diodes.

On-Surface Radical Oligomerisation: A New Approach to STM Tip-Induced Reactions

2018 ◽  
Author(s):  
Gaolei Zhan ◽  
Younes Makoudi ◽  
Judicael Jeannoutot ◽  
Simon Lamare ◽  
Michel Féron ◽  
...  
Keyword(s):  
Sample Surface ◽  
Scanning Tunnelling Microscope ◽  
Transfer Event ◽  
New Approach ◽  
The Past ◽  
Organic Nanostructures ◽  
Scanning Tunnelling ◽  
New Strategy ◽  
Surface Fabrication ◽  
And Control

Over the past decade, on-surface fabrication of organic nanostructures has been widely investigated for the development of molecular electronic devices, nanomachines, and new materials. Here, we introduce a new strategy to obtain alkyl oligomers in a controlled manner using on-surface radical oligomerisations that are triggered by the electrons/holes between the sample surface and the tip of a scanning tunnelling microscope. The resulting radical-mediated mechanism is substantiated by a detailed theoretical study. This electron transfer event only occurs when <i>V</i><sub>s</sub> < -3 V or <i>V</i><sub>s</sub> > + 3 V and allows access to reactive radical species under exceptionally mild conditions. This transfer can effectively ‘switch on’ a sequence leading to formation of oligomers of defined size distribution due to the on-surface confinement of reactive species. Our approach enables new ways to initiate and control radical oligomerisations with tunnelling electrons, leading to molecularly precise nanofabrication.

Integrating Bioinformatics Strategies in Cancer Immunotherapy: Current and Future Perspectives

2020 ◽  
Vol 23 (8) ◽  
pp. 687-698 ◽  
Author(s):  
Houda N. Washah ◽  
Elliasu Y. Salifu ◽  
Opeyemi Soremekun ◽  
Ahmed A. Elrashedy ◽  
Geraldene Munsamy ◽  
...  
Keyword(s):  
Cancer Immunotherapy ◽  
Therapeutic Potential ◽  
Cell Cancer ◽  
Full Potential ◽  
Future Perspectives ◽  
The Past ◽  
Bioinformatics Tools ◽  
Treatment Paradigm ◽  
Immunotherapy Of Cancer ◽  
Significant Attention

For the past few decades, the mechanisms of immune responses to cancer have been exploited extensively and significant attention has been given into utilizing the therapeutic potential of the immune system. Cancer immunotherapy has been established as a promising innovative treatment for many forms of cancer. Immunotherapy has gained its prominence through various strategies, including cancer vaccines, monoclonal antibodies (mAbs), adoptive T cell cancer therapy, and immune checkpoint therapy. However, the full potential of cancer immunotherapy is yet to be attained. Recent studies have identified the use of bioinformatics tools as a viable option to help transform the treatment paradigm of several tumors by providing a therapeutically efficient method of cataloging, predicting and selecting immunotherapeutic targets, which are known bottlenecks in the application of immunotherapy. Herein, we gave an insightful overview of the types of immunotherapy techniques used currently, their mechanisms of action, and discussed some bioinformatics tools and databases applied in the immunotherapy of cancer. This review also provides some future perspectives in the use of bioinformatics tools for immunotherapy.

scholarly journals High-performance quasi-2D perovskite light-emitting diodes: from materials to devices

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Li Zhang ◽  
Changjiu Sun ◽  
Tingwei He ◽  
Yuanzhi Jiang ◽  
Junli Wei ◽  
...  
Keyword(s):  
Energy Transfer ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Structural Characteristics ◽  
Quantum Yields ◽  
Research Directions ◽  
Light Emitting ◽  
Perovskite Materials ◽  
Quantum Confinement Effects ◽  
Semiconducting Properties

AbstractQuasi-two-dimensional (quasi-2D) perovskites have attracted extraordinary attention due to their superior semiconducting properties and have emerged as one of the most promising materials for next-generation light-emitting diodes (LEDs). The outstanding optical properties originate from their structural characteristics. In particular, the inherent quantum-well structure endows them with a large exciton binding energy due to the strong dielectric- and quantum-confinement effects; the corresponding energy transfer among different n-value species thus results in high photoluminescence quantum yields (PLQYs), particularly at low excitation intensities. The review herein presents an overview of the inherent properties of quasi-2D perovskite materials, the corresponding energy transfer and spectral tunability methodologies for thin films, as well as their application in high-performance LEDs. We then summarize the challenges and potential research directions towards developing high-performance and stable quasi-2D PeLEDs. The review thus provides a systematic and timely summary for the community to deepen the understanding of quasi-2D perovskite materials and resulting LED devices.

Sign in / Sign up

Export Citation Format

Share Document