Download or read book Radiation Effects on the Electronic Properties of Carbon Nanotube Thin Films and Advanced Solar Cells written by Hemali G. Shah and published by . This book was released on 2008 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Solar cells and carbon Nanotube films are exposed to proton and neutron radiation while in low earth orbit, geosynchronous orbit, deep space and upper atmosphere. This type of radiation is capable of causing various types of damage to these devices. The type, energy range and influence of the irradiation will depend on the environment of the space mission. The objective of this study is to evaluate the radiation tolerance of novel solar cell devices and carbon Nanotube films." (vi)
Download or read book Carbon nanotubes and graphene for photonic applications written by B.A. Baker and published by Elsevier Inc. Chapters. This book was released on 2013-08-31 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon nanotubes have been explored in light-harvesting and photovoltaic devices because of their unique optoelectronic properties. This chapter provides a brief description of the optoelectronic properties of carbon nanotubes, particularly single-wall carbon nanotubes (SWCNTs), and their implication in various solar cell applications including donor–acceptor solar cells, polymer solar cells, and dye-sensitized solar cells, where carbon nanotubes are utilized as photoactive materials. Carbon-nanotube-based electrodes in photovoltaic devices are also introduced. Carbon-nanotube-based light-harvesting devices are reviewed in terms of fabrication and material processing as well as performance. Finally, advanced emerging methods and the future outlook for carbon-nanotube-based solar cells are discussed.
Download or read book Carbon Nanotubes written by Mohamed Berber and published by BoD – Books on Demand. This book was released on 2016-07-20 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book shows the recent advances of the applications of carbon nanotubes (CNTs), in particular, the polymer functionalized carbon nanotubes. It also includes a comprehensive description of carbon nanotubes' preparation, properties, and characterization. Therefore, we have attempted to provide detailed information about the polymer-carbon nanotube composites. With regard to the unique structure and properties of carbon nanotubes, a series of important findings have been reported. The unique properties of carbon nanotubes, including thermal, mechanical, and electrical properties, after polymer functionalization have been documented in detail. This book comprises 18 chapters. The chapters include different applications of polymer functionalization CNTs, e.g. photovoltaic, biomedical, drug delivery, gene delivery, stem cell therapy, thermal therapy, biological detection and imaging, electroanalytical, energy, supercapacitor, and gas sensor applications.
Download or read book Tuning the Electronic Properties of Carbon Nanotube Thin Films Through Hybrid Networks written by Derrick Liu and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Single-walled carbon nanotubes (SWNT), is a well known material which has been continuously investigated for its exceptionally unique optical, mechanical and electrical properties. The nanotubes, which can be semiconducting, metallic or semi-metallic offers a wide range of practical applications for electronics. Recent breakthroughs in studies focusing on the use of SWNT films for large area and cost effective macroelectronics represents the most realistic near-term goal of integrating SW\NT into real world devices. The focus of this study continues to build upon the use of SWNT for such devices while simultaneously investigating the effect of hybrid networks in hopes of fine tuning the electronic behavior. It has been known that the transport within SWNT is largely affected by its surrounding environment and doping can be achieved by means of charge transfer through adsorption of atoms or molecules. Recent investigations have demonstrated that polymer coating of the device may influence the electronic properties of SWNT such as the ability to control the polarity of the device. Further investigation of this phenomenon and practical utilization of hybrid networks may offer new breakthroughs for transistor and transparent conductors. We report an interesting case of photoresponsive organic transistors based on carbon nanotube fullerene composites, where a sparse, solution deposited single walled carbon nanotube network is intimately coated with fullerene molecules. Under correct network formation a reduction in drain current was observed under illumination. Transistors operated in the on-state resulted in drain currents on an order of magnitude of 10^-9 A, under illumination the on-state may be reversed, rendering these devices insulating with drain currents of 10^-12 A. It is believed that the fundamental mechanism for this phenomenon is heavily influenced by the selective formation of fullerene molecules along the carbon nanotube surface/junctions. This results in a two-fold process of exciton splitting and annihilation of free carriers upon recombination followed by subsequent charge trapping which effectively screens the gate voltage. The negative photoresponsivity can be observed even under low voltage operations. High junction resistances which continue to plague the development of highly conductive transparent carbon nanotube networks can be overcome through fine tuning of electronic behavior. Using highly electronegative fluorofullerenes, semiconducting nanotubes can be heavily doped, improving charge transport along the tube while reducing the junction resistance in contact with metallic tubes. Sheet resistances at high transparencies surpassing some of the best reported literature values can be obtained. Combining the largely solution processable approach and the effective tuning of carbon nanotube films through hybrid networks, one may gain additional insight in the field of nanoscaled science and of carbon nanotubes while opening new possibilities in the field of carbon nanotube electronics.
Download or read book Carbon Nanotube Transparent Electrodes for Photovoltaic Applications written by Michael Wallace Rowell and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Virtually all solar cells require a transparent and conductive (TC) layer on the top surface that allows sunlight to enter the cell and photoexcited charge to be conducted laterally across the top surface. The impact on power conversion efficiency due to reflection, absorption, resistive losses and lost active area is a reduction by 10 -- 25 %, relative. Historically, doped metal oxides such as tin doped indium oxide (ITO) have been used. In the last several years, however, there has been renewed interest in this area with the development of several new nanostructured materials, many of which have the potential for performance, processing, and cost advantages. In the first portion of this work, we describe TC related efficiency losses in detail for the two major categories of solar cells. For thin film monolithically integrated modules, TC related losses can be as high as 25 % and for standard modules of cell strung together losses are typically 10 -- 15 %. For the purpose of developing new TC materials, we specify the material performance requirements for a competitive TC material and show the expected TC related efficiency losses in photovoltaic (PV) modules for any material of known electrical and optical properties. We then provide an overview of the leading nanostructured materials and show that carbon nanotubes (CNT) have basic optoelectronic material properties that are superior to traditional metal oxides. We exhibit the first demonstration of a highly flexible organic solar cell using carbon nanotube films as the TC. The achieved power conversion efficiency of 2.5 % is comparable to the 3.0 % efficiency of the control device using ITO and the flexibility of the CNT device is far greater. Finally, we detail an in-depth investigation of the electrical properties of carbon nanotube networks in order to determine and understand the performance limitations. For this, we develop a novel method of atomic force microscope (AFM) scratch lithography in order to isolate individual CNT bundles and a novel method of electric force microscopy (EFM) in order to quantitatively measure local contact resistances on the nanoscale between CNT bundles. We measure bundle-to-bundle junction resistance for a range of bundle diameters which reveals a previously unobserved inverse scaling of contact resistance with diameter. Values range from 1 kOhm to 200 kOhm for bundle diameters typical of CNT TC networks. We also measure the resistivity of ropes of bundles and we find that this resistance is very high and limits the conductivity of the CNT TC films studied in this work. The structure property relationships revealed from these measurements clearly show what type of morphology control is necessary for high performance CNT TCs and that increasing tube length and/or decreasing junction resistance are the primary routes for further increases in performance.
Download or read book The Effects of Local Chemistry on the Growth and Electronic Properties of Carbon Nanotubes written by Jason M. Simmons and published by . This book was released on 2006 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Damage Effects on Carbon Nanotube Thin Films written by Jeremy S. Best (CAPT, USMC) and published by . This book was released on 2013 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Thin Film Carbon Nanotube Solar Cells written by Colin Klinger and published by . This book was released on 2011 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiation Response and Optical Characterization of Carbon Based Thin films Prepared by Saddle Field Plasma Enhanced Chemical Vapor Deposition written by Sameh Hegazy and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon based thin-film materials have been attracting a lot of attention in many research fields due to their unique material properties. Detection of ionizing radiation is an important application that carbon and diamond based materials, which offer a promising detection material with low manufacturing cost and a variety of physical characteristics for different detection applications. In the current study, the direct current (DC) saddle field Plasma Enhanced Chemical Vapor Deposition (PECVD) method was used to prepare a set of nano-crystalline diamond samples. The relation between the deposition pressure, the gases mixing ratios and the resultant film characteristics were studied. The optical, microstructure and electronic properties of the prepared samples were studied using Raman spectroscopy, FTIR, UV-Visible spectroscopy and I -V characteristics methods. It was found that, an increase in the hydrogen content in the gas mixture leads to a decrease in the crystallinity of the resultant film. A set of samples were selected with different crystalline content and defect DOS to investigate the impact of these parameters on the material's radiation response. It was determined that, the sample with relatively high degree of crystallinity and with the presence of defects close to the valence show promising responses for radiation detection applications. We attributed this results to the fact that, transport is dominated by electrons and shallow defects near the conduction band act as electron traps. On the other hand, hole-traps near the valence band do not have the same impact on the overall transport properties.
Download or read book Evaluation of Thermal Effects on the Mechanical and Electrical Properties of Carbon Nanotube reinforced Polyelectrolyte Thin Film Sensors written by Mles Farrell and published by . This book was released on 2011 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solution processed Thin Films for Electronics from Single walled Carbon Nanotubes and Graphene written by Goki Eda and published by . This book was released on 2009 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single-walled carbon nanotubes (SWNTs) and graphene are sp2 hybridized carbon nanostructures which exhibit extraordinary electronic properties arising from their unique energy dispersions and dimensionalities. A major issue preventing implementation of these materials into integrated electronic devices is the absence of large-scale controllable synthesis and subsequent manipulation. To circumvent this issue, solution processing of SWNTs and graphene has been proposed. Deposition of thin film networks allows the realization of a new class of materials that are useful for large-area or "macro-electronics" on flexible and inexpensive platforms. In this thesis, controllable and efficient solution-based deposition of SWNT and graphene thin film networks and their opto-electronic properties are investigated. Topics such as material dynamics in liquid, chemical structures, defects, morphology, and doping are studied utilizing various spectroscopy and microscopy analysis along with complementary electrical measurements. Further insight is provided through demonstrations of proof-of-principle thin film transistors, organic photovoltaics, and field emitters based on solution-processed SWNT and graphene thin films.
Download or read book Carbon Nanotube Thin Film Solar Cell written by and published by . This book was released on 2012 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Single Wall Carbon Nanotubes as Transparent Electrodes in Cu In Ga Se2 based Solar Cells written by and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a new thin-film solar cell structure in which the traditional transparent conductive oxide electrode (ZnO) is replaced by a transparent conductive coating consisting of a network of bundled single-wall carbon nanotubes. Optical transmission properties of these coatings are presented in relation to their electrical properties (sheet resistance), along with preliminary solar cell results from devices made using CuIn1-xGaxSe2 thin film absorber materials. Achieving an energy conversion efficiency of>12% and a quantum efficiency of ~80% demonstrate the feasibility of the concept.
Download or read book Application of Single Wall Carbon Nanotubes as Transparent Electrodes in Cu In Ga Se2 Based Solar Cells Preprint written by and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a new thin-film solar cell structure in which the traditional transparent conductive oxide electrode (ZnO) is replaced by a transparent conductive coating consisting of a network of bundled single-wall carbon nanotubes. Optical transmission properties of these coatings are presented in relation to their electrical properties (sheet resistance), along with preliminary solar cell resultsfrom devices made using CuIn1-xGaxSe2 thin-film absorber materials. Achieving an energy conversion efficiency of >12% and a quantum efficiency of80% demonstrate the feasibility of the concept. A discussion of the device structures will be presented considering the physical properties of the new electrodes comparing current-voltage results from the new solar cell structure and those fromstandard ZnO/CdS/Cu(In,Ga)Se2/Mo solar cells.
Download or read book Formation and Electronic Properties of In2S3 Cu in Ga Se2 Junctions and Related Thin Film Solar Cells written by Paul Pistor and published by . This book was released on 2009 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural and Electronic Properties of Nanocrystalline Silicon Thin Film Solar Cells Fabricated by Hot Wire and ECR plasma CVD Techniques written by Kamal Kumar Muthukrishnan and published by . This book was released on 2007 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the second part of this work, we focus primarily on the fabrication and analysis of the electronic properties of solar cells using nanocrystalline intrinsic layers. Apart from measuring the regular I-V characteristics and quantum efficiency, we investigate the critical device properties such as the defect densities in the intrinsic layer and the diffusion length of the minority carriers. By correlating the device results with the structural properties of the films, we are able to conclude that the maximum diffusion length and the minimum defect density can only be attained by depositing the intrinsic layers that are close to the transition to amorphous phase. Although few studies have been done on this transition regime of the deposited films, most of them have concentrated only on the film properties such as conductivity ratios and crystalline fractions. This work clearly describes why transition region is ideal for the fabrication of high efficiency solar cells and what are the critical deposition parameters that are involved in their design.
Download or read book Thermally Activated Delayed Fluorescence Organic Light Emitting Diodes TADF OLEDs written by Lian Duan and published by Woodhead Publishing. This book was released on 2021-10-15 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes (TADF-OLEDs) comprehensively introduces the history of TADF, along with a review of fundamental concepts. Then, TADF emitters with different colors, such as blue, green, red and NIR as well as white OLEDs are discussed in detail. Other sections cover exciplex-type TADF materials, emerging application of TADF emitters as a host in OLEDs, and applications of TADF materials in organic lasers and biosensing. - Discusses green, blue, red, NIR and white TADF emitters and their design strategies for improved performance for light-emitting diode applications - Addresses emerging materials, such as molecular and exciplex-based TADF materials - Includes emerging applications like lasers and biosensors
