Query: Plexcitonics fundamental principles and optoelectronic applications

Candidate papers:

abstract: The nanoscale confinement and coupling of electromagnetic radiation into plexcitonic modes has drawn immense interest because of the innovative possibilities for their application in light harvesting and light emitting devices (LEDs) Plexcitons arise from the coupling between two types of quasiparticles, plasmons and excitons, and can be distinguished by the strength of the coupling into strong and weak coupling regimes. Plexcitons have been used to modulate the rate of Forster type resonance energy transfer in quantum dot assemblies and enhance the spontaneous emission rate in quantum dot LEDs. The clearest examples of a plexcitonic enhancement of photocatalytic reaction rates have been evidenced in hybrid systems wherein the strongly bound exciton found in 2D sheet like semiconductors is coupled to the surface plasmon resonance of close lying noble metal nanoparticles. Plexcitonic photocatalysts and solar cells aim to increase the lifetime of hot carriers and thereby enhance the quantum yields for energy harvesting. Since plexcitonics requires the placement of plasmonic and excitonic components in close proximity with one another to facilitate their coupling, it provides a rich arena for chemists and materials scientists to form deterministic and non deterministic arrays and heterojunctions involving noble metal thin films and nanostructures, quantum dots and dye molecules. This review summarizes the dynamics of plexcitons in the various composite systems and provides an overview of the latest theoretical and experimental developments in the field of plexcitonics.
author_names: Ajay P Manuel

Aaron Kirkey

Najia Mahdi

Karthik Shankar
title: Plexcitonics fundamental principles and optoelectronic applications
year: 2019

abstract: ZnS, as one of the first semiconductors discovered and a rising material star, has embraced exciting breakthroughs in the past few years. To shed light on the design principles and engineering techniques of ZnS for improved/novel optoelectronic properties, the fundamental mechanisms and commonly employed strategies are proposed in this review. Recent progress on modifications of ZnS allows it to be extensively and effectively used in versatile applications, including transparent conductors, UV photodetectors, luminescent devices, and catalysis, which are clearly and comprehensively summarized in this work. Novel functional devices springing up from the newly developed ZnS based materials are highlighted as well. This review not only provides a scientific insight into the advances of ZnS based materials, but also touches on the future opportunities in this inspiring field.
author_names: Xiaojie Xu

Siyuan Li

Jiaxin Chen

Sa Cai

Zhenghao Long

Xiaosheng Fang
title: Design Principles and Material Engineering of ZnS for Optoelectronic Devices and Catalysis
year: 2018

abstract: Defects in 2D materials are becoming prominent candidates for quantum emitters and scalable optoelectronic applications. However, several physical properties that characterize their behavior, such as charged defect ionization energies, are difficult to simulate with conventional first principles methods, mainly because of the weak and anisotropic dielectric screening caused by the reduced dimensionality. We establish fundamental principles for accurate and efficient calculations of charged defect ionization energies and electronic structure in ultrathin 2D materials. We propose to use the vacuum level as the reference for defect charge transition levels (CTLs) because it gives robust results insensitive to the level of theory, unlike commonly used band edge positions. Furthermore, we determine the fraction of Fock exchange in hybrid functionals for accurate band gaps and band edge positions of 2D materials by enforcing the generalized Koopmans' condition of localized defect states. We found the obtained fractions of Fock exchange vary significantly from 0.2 for bulk $h$ BN to 0.4 for monolayer $h$ BN, whose band gaps are also in good agreement with experimental results and calculated GW results. The combination of these methods allows for reliable and efficient prediction of defect ionization energies (difference between CTLs and band edge positions) We motivate and generalize these findings with several examples including different defects in monolayer to few layer hexagonal boron nitride $h$ BN) monolayer MoS$_2$ and graphane. Finally, we show that increasing the number of layers of $h$ BN systematically lowers defect ionization energies, mainly through CTLs shifting towards vacuum, with conduction band minima kept almost unchanged.
author_names: T J Smart

Feng Wu

Marco Govoni

Yuan Ping
title: Fundamental Principles for Calculating Charged Defect Ionization Energies in Ultrathin Two Dimensional Materials.
year: 2018

abstract: Fossil fuels have been in the center of the global energy consumption for many years, contributing to serious complications in the environment and becoming gradually exhausted. Hence, seeking low cost and efficient renewable energy sources represents an important aim for the next years. Devices based on organic photovoltaics (OPVs) have undergone high performances. However, the required cost efficiency balance to make a significant contribution to the global energy production is a remaining goal. This thesis reports the synthesis and characterization of conjugated molecules that can be employed for photovoltaic applications. The work is focused on the design of functional dyes for both bulk heterojunction (BHJ) solar cells and dye sensitized solar cells (DSSC) The first chapter introduces the fundamentals of organic electronics, with a particular focus on photovoltaics. The use of functional dyes in the so called third generation solar cells and and details of the principles behind the production of such technologies is covered. The second chapter describes the synthesis and characterization of a collection of new BODIPY derivatives. The materials were successfully applied as donor materials in BHJ solar cells and DSSCs and their performance was studied. The third chapter describes the synthesis and characterization of a library of thiophene based molecules and presents a detailed investigation into the effect of alkyne spacers on the optoelectronic and BHJ properties of the materials. In chapter four, three generations of thiophene based dyes that incorporate di anchoring groups are designed, synthetized and tested in DSSCs. The dyes were used to gain knowledge about the structural parameters contributing to the power conversion efficiency of the di anchoring architecture. The fifth chapter is devoted to the synthesis and characterization of DTS based small molecules and covalently linked donor acceptor unimolecuar systems with the aim of preparing high efficiency BHJ solar cells. Finally, the sixth chapter focuses on the synthesis and characterization of thiophene based macrocycles, and their investigation in BHJ solar cells, with interest in the possible host guest interactions for supramolecular control of the BHJ morphology.
author_names: D Gomes dos Santos

J Marques
title: Synthesis and characterization of functional dyes for optoelectronic applications
year: 2019

abstract: Recently years have witnessed the rapid progress of the halide perovskite materials that could be applied to photovoltaics and light emitting diodes (LED) Due to the structural similarity with respect to the three dimensional (3D) halide perovskite materials, the molecular state of the halide perovskites has received much attention. In this manuscript, we employ first principles calculations to systematically investigate the possible routes to design cesium based molecular halide perovskite material Cs4MX6 via substituting the halide and metal atoms. The substitution method is found to be effective to modulate the electronic and optical properties of the molecular halide perovskites. In particular, the halide mixing is beneficial to improve the optical properties of the Cs4PbX6 molecules. We propose that the molecular halide perovskite Cs4MX6 could be used as organic dye substitutes in various applications. This study is important for the fundamental understanding of the molecular halide perovskite materials and facilitates the design of Cs4MX6 as alternative molecular dyes to be selected for optoelectronic applications.
author_names: Lei Zhang

Kun Xu
title: Understanding substitution effects on dye structures and optoelectronic properties of molecular halide perovskite Cs4MX6 (M=Pb, Sn, Ge; X= Br, I, Cl)
venue: Journal of molecular graphics modelling
year: 2019

abstract: Bismuth telluride (Bi2Te3) a layered compound with narrow band gap has been potentially reported for thermoelectric. However, strong light interaction of Bi2Te3 is an exciting feature to emerge it as a promising candidate for optoelectronic applications within broadband wavelengths. In this study, we investigate structural, electronic and optical properties of Bi2Te3 topological insulator using combination of density functional theory (DFT) and many body perturbation theory (MBPT) approach. With the inclusion of van der Waals (vdW) correction in addition to PBE, the lattice parameters and interlayer distance are in good agreement with experimental results. Furthermore, for the precise prediction of fundamental band gap, we go beyond DFT and calculated band structure using one shot GW approach. Interestingly, our calculated quasiparticle (QP) band gap, Eg of 0.169 eV, is in good agreement with experimental measurements. Taken into account the effects of electron hole interaction by solving Bethe Salpeter equation, the calculated optical properties, namely, imaginary and real parts of complex dielectric function, absorption coefficient, refractive index, reflectivity, extinction coefficient, electron energy loss function and optical conductivity all are in better agreement with available experimental results. Consistencies of our findings with experimental data validate the effectiveness of electron hole interaction for theoretical investigation of optical properties.
author_names: Abdullahi Lawal

Amiruddin Shaari

Rashid S Ahmed

Norshila Jarkoni
title: First principles investigations of electron hole inclusion effects on optoelectronic properties of Bi2Te3, a topological insulator for broadband photodetector
year: 2017

author_names: Subhash C Basak and Guillermo Restrepo
title: Editorial [Hot Topic: Topological and Electrotopological Descriptors of Molecules: Fundamental Principles and Applications to Computer Aided Molecular Design Part I (Guest Editors: Subhash C. Basak and Guillermo Restrepo)
year: 2012

abstract: Investing in energy efficiency and saving is crucial to support energy accessibility and environmental protection, and it is the world's best interest to share and implement forms of energy efficiency. This implies a stronger and effective transnational policy to promote and disseminate know how about new technologies both at the market and R&D level. In this respect, development of projects centered on energy efficient technologies based on nanostructured organic materials certainly is a strategic field. The progresses in mastering organic matter by self assembly and self organization to form ordered softmaterials revolutionized the field opening new frontiers for both fundamental and applied research. However the route towards organic materials for application at the industrial scale is restricted by difficulties in the control and manipulation of the structural organization at the molecular level and its manifestation at higher scales. Motivated by the potential for significant energy savings, the INFUSION project aims to create a strongly interdisciplinary and inter sectorial environment in which the principles of self organization are poured from the Academia into the private sector and vice versa to create new paradigms to engineer electrochromic devices. Through a detailed plan of 83 secondments, the project aims at cross fertilize the electrochromic technology joining specific expertise to realize a bottom up approach toward the design, preparation and characterization of self organized organic materials (chromophores, CNSs, polymers. at different interfaces (ITO, graphene) and exhibiting superior performances (optical, durability. For the transfer of knowledge, the project combines the multidisciplinary expertise of 6 universities, 1 research institute, and 3 companies representing 4 EU and 2 TC countries (Pakistan and Argentina) in the field of organic chemistry, photochemistry, surface science, polymer and materials science, and device engineering.
title: Engineering optoelectronic interfaces: a global action intersecting fundamental concepts and technology implementation of self organized organic materials D4.4 Information brochure (December 2019)
year: 2019

abstract: Heterogeneous interfaces that are ubiquitous in optoelectronic devices play a key role in the device performance and have led to the prosperity of today's microelectronics. Interface engineering provides an effective and promising approach to enhancing the device performance of organic field effect transistors (OFETs) and even developing new functions. In fact, researchers from different disciplines have devoted considerable attention to this concept, which has started to evolve from simple improvement of the device performance to sophisticated construction of novel functionalities, indicating great potential for further applications in broad areas ranging from integrated circuits and energy conversion to catalysis and chemical/biological sensors. In this review article, we provide a timely and comprehensive overview of current efficient approaches developed for building various delicate functional interfaces in OFETs, including interfaces within the semiconductor layers, semiconductor/electrode interfaces, semiconductor/dielectric interfaces, and semiconductor/environment interfaces. We also highlight the major contributions and new concepts of integrating molecular functionalities into electrical circuits, which have been neglected in most previous reviews. This review will provide a fundamental understanding of the interplay between the molecular structure, assembly, and emergent functions at the molecular level and consequently offer novel insights into designing a new generation of multifunctional integrated circuits and sensors toward practical applications.
author_names: Hongliang Chen

Weining Zhang

Mingliang Li

Gen He

Xuefeng Guo
title: Interface Engineering in Organic Field Effect Transistors: Principles, Applications, and Perspectives.
venue: Chemical reviews
year: 2020

abstract: Terahertz radiation (also called T rays) can be employed for spectroscopy and imaging, from the laboratory to industrial applications. In this paper we give an overview of how broadband optoelectronic THz techniques (i.e. using optical lasers to achieve THz generation and detection) can be implemented, and give examples of their unique use in solid state physics, and in biological and industrial applications.
author_names: Wissem Zouaghi

Mark D Thomson

Kaneez Rabia

Robert Hahn

Volker Blank

Hartmut G Roskos
title: Broadband terahertz spectroscopy: principles, fundamental research and potential for industrial applications
year: 2013