Author: Shuchi SharmaPublisher:
ISBN:
Category :
Languages : en
Pages : 132
Book Description
Growth and Characterization of Layered Copper Indium Diselenide Thin Films
Author: Shuchi SharmaGrowth and Characterization of Thin Films of Copper Indium Diselenide and Copper Indium Disulfide for Photovoltaic Applications
Author: Malayanath JeediPublisher:
ISBN:
Category : Solar cells
Languages : en
Pages : 166
Book Description
Growth and Characterization of Copper Indium Boron Diselenide Thin Films
Author: Tobin J. SanteroFabrication and Characterization of Thin Film Copper Indium Diselenide
Author: William J. HollowayOptical and Photovoltaic Properties of Copper Indium-gallium Diselenide Materials and Solar Cells
Author: Puruswottam AryalPublisher:
ISBN:
Category : Copper indium selenide
Languages : en
Pages : 365
Book Description
The demand for clean and renewable energy sources in recent years has motivated research on the development of low cost, thin film photovoltaic devices. As a consequence, tools for the investigation and characterization of thin film photovoltaic component materials and devices, which can be implemented in real time as well as under in-line and off-line measurement conditions, are becoming increasingly important. Real time spectroscopic ellipsometry (RTSE) and ex-situ mapping spectroscopic ellipsometry (SE) are powerful characterization tools suitable for applications in the optimization of device performance and the evaluation of thin film photovoltaics technology scale-up from dot cell sizes in research laboratories to full module sizes in factories. These non-destructive optical probes implement multichannel spectroscopic detection for achieving high measurement speed, while simultaneously yielding high precision light-matter interaction parameters. The interaction parameters can be analyzed to obtain layer thicknesses as well as their optical properties from which material properties such as composition can be determined. The layer thicknesses and their optical properties in turn provide insights into the fraction of incident light absorbed in the active layer of the solar cell and also provide a basis for short-circuit current optimization through optical simulations. In this dissertation research, Cu(In, Ga)Se2 films with different Ga contents have been prepared by a one stage co-evaporation process. These films have been studied by spectroscopic ellipsometry (RTSE) in real time during their deposition, which has been performed at high temperature (570oC). After cooling the films to room temperature, in-situ SE measurements were undertaken in order to extract the dielectric functions of the thin film materials. An extended parameterization was established through the fitting of these dielectric functions to analytical functions, followed by the development of expressions in the free parameters that describe these analytical functions versus the Ga content. As a result of this parameterization, dielectric function spectra can be predicted for any desired composition. This capability was applied for the structural and compositional mapping of CIGS thin films and solar cells deposited over 10 cm × 10 cm substrate areas. Correlations of the deduced structural and compositional parameters with the corresponding device performance characteristics have yielded important insights with the potential to assist in the optimization of solar cell devices incorporating thin CIGS layers. In addition, a methodology of external quantum efficiency simulation (EQE) has been developed that relies on ex-situ spectroscopic ellipsometry analysis of complete thin film solar cells and so does not require free parameters. The simulations have been applied to CIGS and a-Si:H solar cells, based on the assumption that all photo-generated carriers within the active layers of these cells are collected without any recombination losses. Thus, it should be noted the predicted EQE is the maximum that the solar cell having the given structure can generate, and the difference between the predicted and measured EQE for the same device can provide insights into recombination losses in the device. Because the predicted EQE is based on specular interfaces, it can also be lower than the measured values due to light trapping caused by rough surfaces and interfaces. In another research area of interest for CIGS materials and solar cells, the role of the stage II/III substrate temperature (540oC - 640oC) in the deposition of the films by the three stage process has been studied, as has its effect on device performance, sodium diffusion, and grain size. Since standard soda-lime glass does not tolerate temperatures above 570oC due to glass softening, specially engineered high temperature soda-lime glass produced by Nippon Electric Glass Co., Japan was used as the substrate material in this study. It was found that the average device performance improves up to 620oC as a consequence of reduced shunting and improved diode quality factor which affect the fill factor of the device. At 640oC, however, these parameters have exhibited a wider distribution, and thus have yielded a lower average efficiency for the cells. SEM micrographs of these devices showed that the grain size first increased with increasing temperature up to 620oC, and then showed a bimodal distribution at 640oC. Finally, ex-situ mapping ellipsometry has been applied in the study of silver nanoparticle thin films prepared by the drop casting method. These films are important because of the plasmonic effects they exhibit. Such effects can be exploited by integrating the nanoparticle layers into solar cells in order to promote light trapping, and hence, increase the overall efficiency of the cells. A study of these films with mapping spectroscopic ellipsometry provides a means of determining thickness uniformity over large areas that is critical for scale-up of the deposition processes. The uniformity of other parameters of the films such as the plasmon resonance energy and its broadening are equally important to ensure maximum coupling of light into the solar cell absorber layer.
Thin Films Photovoltaics
Author: Beddiaf ZaidiPublisher: BoD – Books on Demand
ISBN: 1839699051
Category : Technology & Engineering
Languages : en
Pages : 114
Book Description
Thin film photovoltaic-based solar modules produce power at a low cost per watt. They are ideal candidates for large-scale solar farms as well as building-integrated photovoltaic applications. They can generate consistent power, not only at elevated temperatures but also on cloudy, overcast days and at low sun angles.Thin film photovoltaics are second-generation solar cells produced by depositing one or more thin layers, or thin films, of photosensitive material on a suitable substrate such as glass, polymer, or metal. Thin film solar cells are based on various materials such as cadmium telluride (CdTe), copper indium gallium diselenide (CIGS), and amorphous thin film silicon (a-Si, TF-Si) are commercially used in several conventional and advanced technologies.
Atomic Layer Deposition of Nanostructured Materials
Author: Nicola PinnaPublisher: John Wiley & Sons
ISBN: 3527639926
Category : Technology & Engineering
Languages : en
Pages : 463
Book Description
Atomic layer deposition, formerly called atomic layer epitaxy, was developed in the 1970s to meet the needs of producing high-quality, large-area fl at displays with perfect structure and process controllability. Nowadays, creating nanomaterials and producing nanostructures with structural perfection is an important goal for many applications in nanotechnology. As ALD is one of the important techniques which offers good control over the surface structures created, it is more and more in the focus of scientists. The book is structured in such a way to fi t both the need of the expert reader (due to the systematic presentation of the results at the forefront of the technique and their applications) and the ones of students and newcomers to the fi eld (through the first part detailing the basic aspects of the technique). This book is a must-have for all Materials Scientists, Surface Chemists, Physicists, and Scientists in the Semiconductor Industry.
Solar Energy Update
Author: Characterization of ALD Copper Thin Films on Palladium Seed Layers for Molecular Electronics
Author: Irene J. HsuPublisher: ProQuest
ISBN: 9780549925088
Category : Copper
Languages : en
Pages :
Book Description
Atomic layer deposition (ALD) is a powerful tool for nanoelectronics. In addition to its role for growing ultrathin films in microelectronics, ALD can be used for controlling critical dimensions on the nanometer scale. In molecular tunnel junctions, the spacing between the metal electrodes must be small enough to adsorb individual or small groups of molecules, on the order of 1-2 nm. This condition makes ALD an ideal process to fabricate nanoelectronic devices because it provides subnanometer thickness control. A method for fabricating monolithic nanoscopic tunnel junctions (MNTJs) for tunneling spectroscopy measurements using atomic layer deposition (ALD) of copper on palladium seed layers has recently been introduced (Gupta et al, Appl. Phys. Lett. v. 207). A critical need for tunneling spectroscopy and other molecular electronics measurements is to characterize the composition and structure of the electrodes. The ALD grown layers are characterized here using planar thin films as models for the electrode composition and structure. ALD grown copper films using a varying number of cycles on thick palladium seed layers were investigated using transmission electron microscopy (TEM), Auger electron spectroscopy (AES), glancing incidence x-ray diffraction (GIXRD), and x-ray photoelectron spectroscopy (XPS) to investigate the chemical composition and structure of the electrodes. Electron diffraction and GIXRD show that as copper is deposited, the deposited layer progresses from palladium-rich to becoming predominately copper. In contrast, AES data show that significant palladium consistently remains on the surface of the growing film. The divergence in surface and bulk behaviors is attributed to palladium surface segregation that is driven by hydrogen adsorption during the ALD process. A diffusion model was created to explain the behavior of palladium movement through the film. Platinum was demonstrated to be a viable alternative seed layer for copper ALD growth, leading to pure copper films, in contrast with results for palladium. This is because hydrogen adsorption does not induce platinum surface segregation. A smaller diffusion rate for platinum in copper may also contribute to the purity of the ALD copper layers on platinum. However, whereas palladium leads to relatively smooth surfaces, platinum seed layers produce copper films that have larger grains and rougher surfaces. Overall, we demonstrate how composition and structure of the electrodes can be measured and controlled using ALD deposited layers. Extension of the methods to real devices with three dimensional structures is discussed. This approach is promising for future nanoelectronic devices based on active molecular devices.
Handbook of Research on Nanoscience, Nanotechnology, and Advanced Materials
Author: Bououdina, MohamedPublisher: IGI Global
ISBN: 1466658258
Category : Technology & Engineering
Languages : en
Pages : 641
Book Description
The burgeoning field of nanotechnology has led to many recent technological innovations and discoveries. Understanding the impact of these technologies on business, science, and industry is an important first step in developing applications for a variety of settings and contexts. Handbook of Research on Nanoscience, Nanotechnology, and Advanced Materials presents a detailed analysis of current experimental and theoretical approaches surrounding nanomaterials science. With applications in fields such as biomedicine, renewable energy, and synthetic materials, the research in this book will provide experimentalists, professionals, students, and academics with an in-depth understanding of nanoscience and its impact on modern technology.