Special Issue Editor
* Correspondence: firstname.lastname@example.org
1 State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 155 Yangqiao West Road, Fuzhou, Fujian 350002, China
2 Institut für Chemie and IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany
Interests: Optoelectronic materials and devices, Flexible electronics, Surface and interface, Charge carrier dynamics, Semiconductor physics, Solar cells, Transistors, Sensors.
Special Issue Information
Aim and Scope: Flexible electronics have attracted great attention due to their salient features and significant roles in the fields of energy, information, sensing, displays, smart skins, wearable systems, biomedical diagnostics, and artificial intelligence, etc. The past years have witnessed the rapid development of advanced materials and devices for flexible electronics. This special issue aims to collect high quality articles focused on thin-film materials, devices and carrier dynamics in flexible electronics and optoelectronics. It is desirable to search a variety of functional films including metallic, organic, inorganic, hybrid and composite materials for developing different types of flexible transistors, sensors, actuators, photodetectors, photovoltaic devices, light-emitting devices and beyond. It may contain, but not limited to material design, thin-film processing, structure regulation, property optimization, structure-property relationship, device engineering, and potential applications. Meanwhile, fundamental investigations on surface and interface characteristics, energy level alignments, charge and energy transfer processes, device operation mechanisms, and carrier dynamics related with advanced techniques such as ultrafast transient absorption and time-resolved (TR) spectroscopy, are welcome for understanding the thin-film materials and flexible devices.
We kindly invite you to submit a manuscript(s) for this Special Issue. Full papers, communications, and reviews are all welcome.
Subtopics: Synthesis and characterization of thin-film semiconductors and dielectrics; Novel electrode materials, interlayers and interface engineering; Stretchable or self-healing materials and devices; Flexible device design and electronic/optoelectronic applications; Charge transfer processes, carrier dynamics and device physics;
Keywords: films; functional materials; organic electronics; optoelectronics; flexible devices; solar cells; field-effect transistors; photodetectors; carrier dynamics; wearable applications.
Deadline for manuscript submissions: 31 December 2020
Manuscript Submission Information
All submissions to Materials International should be made at email@example.com. The corresponding author has the responsibility of the manuscript during the submission and peer-reviewing process. Please do not forget to state in the email “Subject” the title of this special issue.
- read the Aim & Scope to gain an overview and assess if your manuscript is suitable for this journal;
- use the Microsoft Word Template to prepare your manuscript;
- make sure that issues about publication ethics, copyright, authorship, figure formats, data and references format have been appropriately considered;
- please try to cite only articles with DOI (digital object identifier); also add DOI for each reference;
- please add at least 10 references from the last 2 years (2018-2019) in order to highlight the novelty of your work;
- ensure that all authors have approved the content of the submitted manuscript.
(1) Flexible PCB Coils for Wireless Power Transfer System Using Low-Frequency Electromagnetic Induction
1 State Grid Yili Electric Power Supply Co. Ltd, Yili City83500, Xinjiang P.R. China
2 State grid Ezhou Electric Power Supply co., Ltd, Ezhou 43600, China
3 Zhejiang Landun Electrical New Material Technologies L.td, Hangzhou311418, China
4 School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
† these authors contributed equally to this work
1) Anodic polymerization of two salicyl-based monomers: Electrochemical and optical studies
Mounia Guergouri1*, Rafik Bensegueni1,2, Kharouba Madjid1, Ammar Khelifa Baghdouche1.
1Laboratoire de Chimie des Matériaux Constantine, Université des Frères Mentouri, Constantine 25000, Algeria.
2Université Mohamed Cherif Messaadia, 41000 Souk Ahras, Algérie.
We synthesized two novel monomers, 2-(9H-fluoren-7-yliminomethyl)phenol (SIF) and 2-(9-ethylcarbazol-3-yliminomethyl)phenol (SIC), by condensation between salicylaldehyde and corresponding amine, 9H-fluoren-2-amine and 9-ethyl-9H-carbazol-3-amine, respectively. Thus, we investigated the electrochemical behaviours of the two products on a GCE electrode by cyclic voltammetry. Each monomer shows two peaks, recorded vs Ag/AgCl reference electrode at 1,27 and 1,78 eV for SIF and at 1,12 and 1,45 eV for SIC. Their polymerization was achieved by a potentiostatic method in an appropriate solvent-electrolyte mixture (Bu4NBF4 (0.1 M) / MeCN). We have characterized the corresponding polymers, poly2-(9H-fluoren-7-yliminomethyl)phenol (PSIF) and poly(2-(9-ethylcarbazol-3-yliminomethyl)phenol (PSIC) by cyclic voltammetry, FT-IR and UV-vis spectroscopy. Further, we calculated the corresponding electrochemical and optical bandgaps and their values are equal to 1,43 and 1,96 eV for PSIF and 1,73 and 1,99 eV for PSIC, respectively.
Keywords: Conductive polymer, electropolymerization, cyclic voltammetry, bandgap.
2) Role of CdSe Quantum Dot on Electrical Conductivity of Chitosan/PCL Thin Films
A.M. Abdelghany1, M.S. Meikhail2 and W.M. Awad1
1 Spectroscopy Dept., Physics Division, National Research Center, 33 Elbehouth St., Cairo, 12311, Egypt.
2 Physics Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt.
Chitosan, which has low conductivity, was blended with poly(ϵ-caprolactone), PCL, which has a fast ionic motion for facilitating ionic conduction. Besides, Semiconducting CdSe quantum dots were embedded within the thin film polymeric matrix to enable uses in different applications. The dielectric constant, ϵ’, of synthesized polymer composite, was found to be a constant with respect to temperatures and attributed to the decrease in charge carriers and their mobility. Experimental data reveal that the hopping mechanism administrates both the transport of charge carriers and also their relaxation.
At low frequencies, the loss tangent, tan δ, increases to a maximum value with increasing frequency and then decreases again at a higher frequency. Semicircles were observed in Cole-Cole diagrams at temperature 20oC with their center below the X-axis, indicating the presence of dielectric relaxation over a wide range.
Keywords: Chitosan; PCL; thin film; CdSe; QDs; Ac Conduction.
3) On approach to increase integration rate of elements of a injection locked oscillator
1. Nizhny Novgorod State University, 23 Gagarin avenue, Nizhny Novgorod, 603950, Russia
2. Nizhny Novgorod State Technical University, 24 Minin Street, Nizhny Novgorod, 603950, Russia
In this paper we introduce an approach to increase integration rate of elements of a injection locked oscillator. Framework the approach we consider a heterostructure with special configuration. Several specific areas of the heterostructure should be doped by diffusion or ion implantation. Annealing of dopant and/or radiation defects should be optimized. An analytical approach for modelling of technological process has been also introduced. The approach gives a possibility to analyze mass and heat transport in multilayer structures without crosslinking of solutions on interfaces between layers. The approach also gives a possibility to take into account spatial and temporal variation of parameters of considered processes. Based on this approach we analyzed manufacturing an integrated circuit to increase density of elements.
Keywords: injection locked oscillator; optimization of manufacturing; heterostructure with special configuration; analytical approach for modelling.
4) Fabrication and characterization of sol-gel screen printed Zn: CdO (ZCO) thick film for optoelectronic and photovoltaic technologies
Vipin Kumar1*, Renu Kumari1, Dhirendra Kumar Sharma1, Kapil Sharma1, V. K. Sachan2
1 Department of Physics, KIET Group of Institutions, Delhi NCR, Ghaziabad, India
2 Department of Electronics and Communication Engg. KIET Group of Institutions, Delhi NCR, Ghaziabad, India
We present report on Zn doped (5%) CdO thick film fabricated on to the glass substrate (pre-cleaned) by using sol-gel screen –printing process. The deposited sintered Zn: CdO film were then subjected to XRD, SEM, EDX, UV-Vis spectroscopy, PL spectroscopy and dark conductivity measurement studies. The XRD study of sintered film revealed the polycrystalline nature and confirmed that Zn: CdO film belongs to cubic crystalline structure. SEM study provides the information on morphology of Zn: CdO film. The EDX study confirms the existence of Cd, O and Zn in the sintered film. The UV-Vis spectroscopy via reflectance mode confirms the direct transition of band gap with a value of 2.60 eV. PL spectra of the sintered film exhibited a strong near band edge emission located around 500 nm. The Arrhenius plot (log σDC Vs 1000/T) confirms the semiconducting nature for the sintered film.
Keywords: Sol gel screen printing, XRD, UV-Visible, PL spectra.
5) Passivating Si and Ge surfaces using a facile sonochemical method
V. Shmid, A. Podolian, А. Nadtochiy, O. Korotchenkov
Faculty of Physics, Taras Shevchenko National University of Kyiv, Kyiv 01601, Ukraine
Ultra-thin chips made from thinned Si wafers that offer remarkable levels of bendability without failure have being considered to be ideal for utilizing in flexible electronics. Of significance are also silicon-based materials, such as SiGe, which are compatible with micro-processed Si wafers and used as thin films in ultra-fast strained bipolar complementary metal oxide semiconductor (BiCMOS) channels and low-resistive contacts. Due to a lattice mismatch of Si and Ge, these Si-Ge systems provide high levels of strain thus rendering capabilities of bending and stretching on the wafer surfaces and in the interface regions. To yield heterogeneously integrated electronic devices, low surface and interface trap densities have to be achieved together with improved inter-layer coupling. Depositing a passivation ﬁlm on Si and Ge surfaces, which affects the carrier recombination velocities at the surfaces, is of great interest in this respect. It was also shown that alkylated Si surfaces are less susceptible to oxidation in air than were hydrogen-terminated Si surfaces. Furthermore, extremely low recombination velocities at CH3-Si(111) surfaces ranging from 10 to 100 cm s-1 were reported. The C-H passivation patterns could also be used to define sites of a strong adhesion to the wafer surfaces. Facile sonochemical treatment steps can offer great potential for performing these tasks. To intensify a functionalization ability of Si and Ge surfaces by chemically bonded C-H chains to dangling bonds and hence improve the lifetimes in Si and Ge, here we propose sonochemical treatments in chloroform (CHCl3) and dichloromethane (CH2Cl2). It is suggested that these carbon sources are decomposed into hydrocarbon chains due to extreme conditions in the solvents and at the etchant/solid interfaces, as temperatures of »5000°C, pressures of »50 MPa and cooling rates greater than 109 K/s are achieved after the growth and following collapse of cavitation bubbles. It is implied that the carbon atoms can then form bonds with the Si and Ge surface atoms thus producing long-chain species on solid Si and Ge surfaces, which form stable surface passivation patterns. Our results show that wet chemical and sonochemical treatments in CHCl3 and CH2Cl2 improve recombination properties of Si, Ge and SiGe surfaces that have been functionalized by H-atoms in standard HF solutions prior to performing a sonochemical step. Surface photovoltage (SPV) decay curves, scanning electron microscopy (SEM) images, energy-dispersive X-ray (EDX) spectra and Fourier transformed-infrared (FTIR) transmission data are reported to show that sonochemical treatments can result in increased SPV signals and prolonged decay times. These results demonstrate that sonochemical technique is an effective tool for passivating Si, Ge and SiGe surfaces in hydrocarbon solutions.
6) New Model Predicting The electric Conductivity of Mono-, and Multilayered Highly Oriented Single-walled Carbon Nanotube Films
Maher S. Amer, Mark Foster, Ali Al Mafrage, and Mohammed K. Mohammed
Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH 45435 USA
We developed a new model capable of accurately predicting the electrical conductivity of highly aligned single-walled carbon nanotube thin films. The films ranged between 1 and 11 layers thick. The well-established Lamination theory failed to predict the experimentally measured values for the films of different thicknesses, However, Our model, based on a modified and expanded techniques applied within realm of the lamination theory, could predict the exact values taking into consideration the inter-layer interaction that is crucial for the properties and performance of nano-films.
7) A critical review of some numerical models for thin films on elastic substrates
Department of Architecture, Università Iuav di Venezia, Venice, Italy
This work is dedicated to a review of a set of simple and effective numerical models for studying the behaviour of thin films on elastic substrates and/or sandwich composites. As well known, in mechanic and electronic engineering fields, thin films on elastic substrates can be modelled by means of beams on elastic supports. For this purpose, the Euler–Bernoulli beam hypothesis is here adopted for representing thin film behaviour, whereas several different laws are assumed for simulating the relationship between elastic substrate vertical displacements and contact tractions. In particular, attention is devoted to Winkler model, two parameter models, and two- and three-dimensional elastic half space models. The review is based on existing contributions, but the resulting comparison and critical evaluation of the use different models for the elastic support represents a novel contribution. In particular, the proposed approach is based on a mixed variational formulation that assumes both thin film displacements and contact tractions between the thin film and the elastic support as independent fields. Assuming perfect adhesion and no friction between the thin film and the support, the influence of the different laws for the elastic substrate is taken into account, by introducing a parameter that considers the ratio between thin film and substrate stiffness. Numerical tests focus on static and buckling analysis of thin films on elastic substrates for varying thin film length and thin film-substrate stiffness ratio.
8) Thin-film materials, devices and carrier dynamics for flexible electronics
Jiewu song1,4, Xiaolong Liu1,2,3,4*, Pengwei Li2,3,4, Yangyang Dang1, Xuesong Li1, Yanlin Song2,3* and Xutang Tao1*
1State Key Laboratory of Crystal Materials, Shandong University, No. 27 Shanda South Road, Jinan 250000, P. R. China
2Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
3University of Chinese Academy of Sciences, Beijing 100049, China
4These authors contributed equally
Abstract: With the rapid development of perovskite photovoltaics, flexible perovskite solar cells (FPSCs) have emerged as promising candidates for solar-power sources to sustainably boost next-generation electronics. For practical advancement, FPSCs must be satisfied with exhibit high power efficiency, low weight, environmental stability, stretchability and twistability, simultaneously. In this Review, we lay out the key points for advancing the development of flexible perovskite solar-power sources, including chemical diversity of perovskite materials, devices structure, and carrier dynamics with representative advances. Finally, we propose a comprehensive summary and perspectives of improvement strategies for future research in FPSCs.
9) Thiophene/carbazole based hole transporting material for perovskite solar cells
Rana Nakara, An-Na Chob, Nicolas Bertona, Jérôme Faure-Vincentc, Johan Jacquemina, François Tran Van a, Nam-Gyu Park*b, Bruno Schmaltz*a.
a Laboratoire de Physico-Chimie des Matériaux et des Electrolytes pour l’Energie (PCM2E), EA6299, Université de Tours, France
b School of Chemical Engineering and Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Korea
c Université Grenoble-Alpes, CEA, CNRS, INAC-SyMMES, F-38000 Grenoble, France.
Abstract: Perovskite solar cells (PSC) based on metal-organic halide perovskites have emerged as one of the most promising photovoltaic technologies. In order to obtain high efficiencies, a hole transporting material (HTM) is required. Huge research efforts have been made to design efficient materials. Carbazole-based HTMs are among the most promising new HTMs. This work has consisted in elaborating new HTMs, based on carbazole moiety to replace spiro-OMeTAD (reference material) in PSC. First, we demonstrate the feasibility of an original way of synthesizing semiconductor molecular glasses from a carbazole-based based intermediate called “synthon”. The synthesis of the synthon was optimized in 6 hours of reaction with an overall yield of 70%. Then, the targeted materials were prepared in a single reaction step from predefined spacer, using the reactivity of the 9-position of the carbazole unit. New molecules based on either bithiophene (B) or terthiophene (T) core have been synthesized. All HTMs, namely Cz-B, Cz-T, Cz-B-Cz and Cz-T-Cz, are end-capped with one or two peripheral carbazole units. The glass transition temperature (Tg) of the materials clearly depends upon the rigidity of the chemical structure of the core. Thermal and opto-electronic properties strongly depend upon the nature of the bridging core or the number of the carbazole units. Results are showing that all 4 new molecules possess suitable properties to be used as HTM in perovskite solar cells. Finally, these materials have been integrated in solar devices and have shown promising results in terms of efficiencies (between 13% and 16%).
Key words: photovoltaic cells, hole transporting materials, perovskite, carbazole, bithiophene, terthiophene.
10) Conductive Composite based on Sodium Alginate/PEDOT:PSS
Jorge Fernandes Filho 1 , Samir Leite Mathias 1 , Bruno Bassi Mlllan Torres 2 , Caio Henrique Gomes 3 , Rafael Henrique Longaresi 1 , Aparecido Junior de Menezes 1, *
1 Programa de P´ós-Graduação em Ciência de Materiais-PPGCM, Universidade Federal de São Carlos-UFSCar, Rodovia João Leme dos Santos, Km 110, Sorocaba, CEP 18052-780, São Paulo, Brazil.
2 Instituto de Física de São Carlos-IFSC, Universidade de São Paulo-USP, Av. Trab. São Carlense, 400 – Parque Arnold Schimidt, São Carlos, CEP 13566-590, São Paulo, Brazil.
3 Faculdade de Engenharia de Sorocaba – FACENS, Rodovia Senador José Ermírio de Moraes, 1425 – Jardim Constantino Matucci, Sorocaba CEP 18085-784 São Paulo, Brazil.
Correspondence: firstname.lastname@example.org; email@example.com
Abstract: The association between the polymers (3,4-ethylenedioxythiophene) and poly (4-styrenesulfonic acid) PEDOT:PSS results in properties found in plastics with electrical characteristics similar to metals. The combination of the PEDOT:PSS with sodium alginate, a polymer from renewable source and found in marine algae, allows the creation of homogeneous thin films. This doped material under an electric current change their colors. The investigation of the resulting electrical properties, as well as the material morphological characteristics and the assembly of an electrochromic device, are the main objectives of this work. The films were assembled using the solvent evaporation method, casting, from aqueous solutions of PEDOT:PSS and sodium alginate in various proportions. Analysis of the voltage versus current curve showed a PEDOT:PSS concentration dependence for increasing the conductivity of the formed film. Profile analysis showed that casting technique produced films of circa 1000 nm and the spin casting technique produced films circa 250 nm of thickness; RX diffractometry (DRX) revealed that the material is predominantly amorphous; UV-Vis absorbance measurements indicated great absorption of light energy in the RGB pattern at length of 650 nm; images from scanning electron microscopy indicated the components’ homogeneity in the formation of the films and the optical microscopy showed the continuity of the films formed. FTIR analyzes demonstrated that the absorption bands are equivalent to those found in the literature. In this way, the synthesized material presents suitable characteristics to be applied in the construction of an electrochromic device.
Keywords: PEDOT:PSS; sodium alginate; renewable material.
11) Characterizing the carrier dynamics in Cu-In-Se based nanocrystalline homojunctions
Shalini Menezes 1, Bryan Larson 2, Nassim Rahimi 3,*
1 InterPhases Solar, Moorpark, CA, USA
2 National Renewable Energy Laboratories, Golden, CO, USA
3 Horiba Instruments Inc., New Jersey USA
Abstract: Recently we introduced radically different and extremely low-cost route to naturally create high quality pn junctions, exemplified by two copper-indium-selenide (CISe) compounds. It entails single-step electrodeposition of inherently ordered, 3D-network of interconnected p-CISe and n-CISe nanocrystals. Besides proven performance and exceptional reliability, the CISe compounds offer self-stabilization, intrinsic doping and wide bandgaps. The approach exploits these attributes to create CISe nanocrystalline homojunction (NHJ) thin-film on large foil. The CISe film can be inserted between 2 electrodes to create an isotropic device that serves either as solar cell or light emitting diode. The pn CISe device can be mass produced in ambient atmosphere, using continuous roll-to-roll processing of device layers. The CISe NHJs exhibit unusual electro-optical attributes. Their spontaneous nanoscale ordering within the film facilitates interpenetration for fast, efficient generation, separation and transport of minority carriers; minimizes recombination and essentially performs the same functions as the high-end planar pn junctions or quantum dot structures, without their fabrication complexities. This paper investigates the dynamics of minority carriers within the CISe NHJ structure using photoluminescence and time-resolved microwave conductivity. Observed quantized energy transitions imply that the CISe grains act as pure nanocrystals or quantum dots.
12) An overview on thin films for optical, electronics, optoelectronic and sensing applications
Helliomar P. Barbosa1, Renata D. Adati2, José Ricardo Cezar Salgado3, Márcio Sousa Góes3, André L. dos Santos4, Regina M. Takeuchi4, Felipe T. Aquino5, Jefferson L. Ferrari1*
- Desenvolvimento de Materiais Inorgânicos com Terras Raras – DeMITeR, Laboratório de Materiais Fotoluminescentes (LAMAF), Instituto de Química – (IQ), Universidade Federal de Uberlândia – (UFU), Av. João Naves de Ávila, 2121 – Bairro Santa Mônica, CEP: 38400-902, Uberlândia, MG, Brazil
- Departamento Acadêmico de Química e Biologia, Universidade Tecnológica Federal do Paraná (UTFPR), 81280-340 Curitiba-PR, Brazil
- Instituto Latino-Americano de Ciências da Vida e da Natureza (ILACVN), Centro Interdisciplinar de Ciências da Natureza, Universidade Federal da Integração Latino-Americana (UNILA), Av. Tancredo Neves, 6731 – Bloco 6, Espaço 3, Sala 10, Cx P. 2044, CEP: 85.867-900, Foz do Iguaçu, PR.
- Institute of Exact and Natural Sciences of Pontal, Federal University of Uberlandia, 38304-402, Ituiutaba, Minas Gerais, Brazil
- Faculdade de Engenharia de Várzea Grande, Universidade Federal de Mato Grosso, Várzea Grande, Brazil
Correspondence: firstname.lastname@example.org and email@example.com
Abstract: The technological development has stimulated the search for new sustainable and low-cost nanomaterials which can improve people’s quality of life. Among the many forms of nanomaterials, thin films have received growing attention due to their unique properties and versatility. Thin films have several applications such as biological systems for antibody detection, flexible films for solar cells, planar waveguide for optical amplification in 3rd Telecom Window, electrodes for sensing, biological systems for antibody detection, energy conversion/storage systems (e.g. solar cell, battery and supercapacitor), among others. The methods to prepare thin films are as diverse as their application that include sol-gel, dip-coating, spin-coating, electrodeposition, chemical vapor deposition, Langmuir-Blodgett (LB), and so on. Therefore, the use of thin-films-based materials is an alternative for configurations, conformity and thickness control for inexpensive and for promising approach to solve many of current problems regarding energy storage and conversion, optical transmission of information, and chemical and biological sensing. Concerning information transmission and amplification of optical signals fields, binary semiconductor oxides with SiO2 as a matrix have been widely used due to their attractive features including the refractive index control, photoluminescent properties when doped with Rare Earths ions (RE3+), and surface roughness. Additionally, in respect of the monitoring of biologically important species, thin-film electrodes have been fabricated and they usually provide high analytical performance coupled with flexibility and long-term stability. These electrodes have allowed developing wearable sensors, which could be used for remote human health monitoring. From a fundamental point of view, thin films have been applied to study molecular interactions that occur at an interface with a controlled organization. Different aspects of monolayer arrangement can be exploited for the preparation of molecular assemblies, which is appointed as a goal for supramolecular chemistry and nanostructures of low dimensional materials, and for applications that include optics, electronics, chemical sensors, as well as biosensors. Finally, taking into account the development of systems for energy storage, the efficiency of batteries and supercapacitors is dependent on the procedure used to synthesize the nanomaterial and the charge transfer processes at the electrode interfaces. Thereby, we will explore the use of novel composite materials in batteries and supercapacitors, especially those that use a mixture of semiconductors and graphene. In this context, this review aimed to present and discuss the main advances in the preparation of thin-film electrodes, planar waveguides based in semiconductor and dielectric, organic-inorganic hybrid, graphene, supercapacitor, electrochemical sensor, for different kind of applications.
Keywords: Films; waveguide; energy-storage; electrodes; energy conversion.
13) Electrical Properties of Thin-Film Capacitors using (h-BN) m (m=1- 4) inside two X-doped graphene electrodes (X= Li, Be, B)
Department of Chemical engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran
Abstract: Nanoscale dielectric capacitors have been widely studied due to their ability to store a high amount of energy. In this research, we have modeled one which is composed of a few dopants graphene layers including Li, Be, B (of second row in Mendeleev table) separated by an insulating medium of a few h-BN layers. It has been indicated that the boron atoms are the suitable dopants for hetero-structures of the X-G/ (h-BN) m/X-G capacitor compared to those from groups IA or IIA. We have speciﬁcally studied the quantum and coulomb blocked effects of diﬀerent h-BN/graphene including hetero-structures, stacks for multi dielectric properties of diﬀerent (h-BN) n/graphene. We have shown that the has appeared in small thickness of capacitor due to number of layers and this effect cannot occur in the layers more than 4 of h-BN, while the m=3 is suitable layer for the capacitor simulation.
Keywords: graphene electrode, boron nitride sheet, nanoscale dielectric capacitors, coulomb blockade.
(14) Vacuum-deposited fluoropolymer thin films for flexible optoelectronics
K. Grytsenko*, Yu. Kolomzarov, P. Lytvyn
V.E. Lashkaryov Institute of Semiconductor Physics, pr. Nauki 41, Kyiv, Ukraine
*Corresponding author: firstname.lastname@example.org
Abstract: Functional thin film materials for rapidly developing flexible electronics are the key factor for successful design of the new devices. Numerous types of sensors, OLED, solar cells etc. can be made on flexible substrate. Fluoropolymer (FP) thin films are characterised with outstanding thermal and chemical stability, biocompatibility and transparency over UV-VIS-NIR regions. Thin films of the most stable FP – polytetrafluoroethylene (PTFE) can be deposited from a gas phase only. But this allows the production from a gas phase the composite films with PTFE matrix, filled with metal and/or dye nanoparticles with required optical properties without restrictions imposed by solubility of components of the film, underlayer and substrate. FP films, deposited by decomposition-evaporation of bulk FP in a vacuum possess the linear macromolecules. This is a proof of flexibility of the FP films, deposited in a vacuum instead of cross-linked FP films deposited by any classic plasma method. The independent modification of FP film structure with additional discharge in FP vapours allows to increase film stability without losing flexibility. The mild plasma treatment allows deposition of uniform FP film on nano-structured plastic substrate.
Keywords: Fluoropolymer, decomposition, vacuum deposition, thin film
(15) Promising role of polymeric membrane in thin film electronics
Abhijit Pal1,2 and Abhijit Bandyopadhyay1,*
1Department of Polymer Science and Technology, University of Calcutta 92, A.P.C. Road, Kolkata 700009, India
2Analytical and Chemical Department, Hari Shankar Singhania Elastomer & Tyre Research Institute (HASETRI), Raghupati Singhania Centre Of Excellence 437, Hebbal industrial Area, Mysore 570016, India
*Corresponding Author: email@example.com
Abstract: Massive improvement in thin film deposition technique of late, has certainly engaged various polymers in a range of flexible electronic applications for example in optical coating, solar cells, storage cells, data storage devices, light emitting diodes, sensors and actuators etc. The structural assembly of such three dimensional micro films primarily depend on its molecular order followed by its scale of bonding on the substrate material. In this chapter we shall describe all advanced techniques of preparation of polymeric thin films and their potential application in thin film electronics. Polymers and copolymers having extended conjugations, called conducting polymers, are liable for such applications. There have been a wide range of homo and copolymers and their derivatives available in intrinsically conducting polymer category which shows a different extent of HUMO-LUMO transition leading to a variable quantum yield. Intrinsic factors like microstructure, surface morphology, crystallite size and extrinsic factor like film thickness, present of a modifier to improve conductivity etc. are likely to affect the conjugation length of the conducting polymers and thus the chapter would also cover a detailed structure-property correlation for such category of polymers in thin film electronic application.
Keywords: Polymer thin film, Electronics, Conducting Polymer, Structure-Property Correlation
(16) Study of the effects in the performance of DSSC’s according to the substances, concentrations and treatments employed in the photoanode and electrolyte of the cell
Kisiev Salgado-Castro (Universidad Latinoamericana)
Irina V. Lijanova (Instituto Politécnico Nacional, Centro de Investigación e Innovación Tecnológica)
Abstract: This present review article, besides describing the basic principles of operation and characterization of dye sensitized solar cells (DSSC’s), develops a qualitative analysis of the effects in Voc, Isc, injected electron efficiency and overall cell’s efficiency; depending on the nature of the semiconductor material, its morphological characteristics, superficial treatments and dopants used in the photoanode construction, as well as the kind of redox couple, its concentrations, additives and solvents employed for the electrolyte.