Development of Back Contacts for CdTe Thin Films Solar Cells

Development of Back Contacts for CdTe Thin Films Solar Cells PDF Author: Fadhil Khalaf Dahash Alfadhili
Publisher:
ISBN:
Category : Photovoltaic cells
Languages : en
Pages : 100

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Book Description
Thin film solar cells based on polycrystalline p-type cadmium telluride (CdTe) represent one of these the most promising photovoltaic (PV) device due to high efficiency and low-cost production. Currently, CdTe solar cells provide the lowest cost electricity generation in utility-scale applications, which is a cost-competitive with the traditional power source, fossil fuel. CdTe thin film PV has attained 22.1 % of power conversion efficiency for small area scale and 18.6 % for modules scale. However, the high efficiency of CdTe devices has been achieved by increasing the photo-generated current by changing the traditional window layer (CdS) of CdTe to a wider bandgap material with better band alignment. The open-circuit voltage (VOC) remains below the theoretical limit due to a barrier at the back of the device due to the deep valence band edge of CdTe (-5.9 eV). Voc can be increased by adding a buffer layer between CdTe and the back electrode to decrease band banding and reducing carrier recombination at the back interface. In this thesis, several materials were investigated as a back-buffer layer, such as single-wall carbon nanotube (SWCNT), zinc telluride (ZnTe), tellurium (Te), and cadmium zinc telluride (CZT) to minimize the bend bending at CdTe/back-buffer layer interface. An alternative method to reduce the carrier recombination at the rear surface, the use of aluminum oxide (Al2O3) layer as a passivation layer was also demonstrated. Finally, an effective method of CdCl2 treatment for CZT thin film was investigated. This method shows that zinc (Zn) can be maintained during the heat treatment.

Development of Back Contacts for CdTe Thin Films Solar Cells

Development of Back Contacts for CdTe Thin Films Solar Cells PDF Author: Fadhil Khalaf Dahash Alfadhili
Publisher:
ISBN:
Category : Photovoltaic cells
Languages : en
Pages : 100

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Book Description
Thin film solar cells based on polycrystalline p-type cadmium telluride (CdTe) represent one of these the most promising photovoltaic (PV) device due to high efficiency and low-cost production. Currently, CdTe solar cells provide the lowest cost electricity generation in utility-scale applications, which is a cost-competitive with the traditional power source, fossil fuel. CdTe thin film PV has attained 22.1 % of power conversion efficiency for small area scale and 18.6 % for modules scale. However, the high efficiency of CdTe devices has been achieved by increasing the photo-generated current by changing the traditional window layer (CdS) of CdTe to a wider bandgap material with better band alignment. The open-circuit voltage (VOC) remains below the theoretical limit due to a barrier at the back of the device due to the deep valence band edge of CdTe (-5.9 eV). Voc can be increased by adding a buffer layer between CdTe and the back electrode to decrease band banding and reducing carrier recombination at the back interface. In this thesis, several materials were investigated as a back-buffer layer, such as single-wall carbon nanotube (SWCNT), zinc telluride (ZnTe), tellurium (Te), and cadmium zinc telluride (CZT) to minimize the bend bending at CdTe/back-buffer layer interface. An alternative method to reduce the carrier recombination at the rear surface, the use of aluminum oxide (Al2O3) layer as a passivation layer was also demonstrated. Finally, an effective method of CdCl2 treatment for CZT thin film was investigated. This method shows that zinc (Zn) can be maintained during the heat treatment.

Development of CdTe Thin Film Solar Cells on Flexible Foil Substrates

Development of CdTe Thin Film Solar Cells on Flexible Foil Substrates PDF Author: Deidra Ranel Hodges
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
ABSTRACT: Cadmium telluride (CdTe) is a leading thin film photovoltaic (PV) material due to its near ideal band gap of 1.45 eV, its high optical absorption coefficient and availability of various device fabrication methods. Superstrate CdTe solar cells fabricated on glass have to-date exhibited efficiencies of 16.5%. Work on substrate devices has been limited due to difficulties associated with the formation of an ohmic back contact with CdTe. The most promising approach used to-date is based on the use of an interlayer between the CdTe and a metal electrode, an approach that is believed to yield a pseudo-ohmic contact. This research investigates the use of ZnTe and Sb2Te3 as the interlayer, in the development of efficient back contacts. Excellent adhesion and minimum stress are also required of a CdTe thin film solar cell device on a flexible stainless steel (SS) foil substrate. Foil substrate curvature, flaking, delamination and adhesion as a result of compressive strain due to the coefficient of thermal expansion (CTE) mismatch between the flexible SS foil substrate and the solar cell films have been studied. A potential problem with the use of a SS foil as the substrate is the diffusion of iron (Fe), chromium (Cr) and other elemental impurities into the layers of the solar cell device structure during high temperature processing. A diffusion barrier limiting the out diffusion of these substrate elements is being investigated in this study. Silicon nitride (Si3N4) films deposited on SS foils are being investigated as the barrier layer, to reduce or inhibit the diffusion of substrate impurities into the solar cell. Thin film CdTe solar cells have been fabricated and characterized by AFM, XRD, SEM, ASTM D3359-08 tape test, current-voltage (I-V) and spectral measurements. My individual contributions to this work include the Molybdenum (Mo) development, the adhesion studies, the silicon nitride (Si3N4) barrier studies, and EDS and SEM lines measurements and analysis of substrate out-diffused impurities. The rest of my colleagues focused on the development of CdTe, CdS, ZnTe, the CdCl2 heat treatment, and other back contact interlayer materials.

Solar Cells and Modules

Solar Cells and Modules PDF Author: Arvind Shah
Publisher: Springer Nature
ISBN: 3030464873
Category : Science
Languages : en
Pages : 357

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Book Description
This book gives a comprehensive introduction to the field of photovoltaic (PV) solar cells and modules. In thirteen chapters, it addresses a wide range of topics including the spectrum of light received by PV devices, the basic functioning of a solar cell, and the physical factors limiting the efficiency of solar cells. It places particular emphasis on crystalline silicon solar cells and modules, which constitute today more than 90 % of all modules sold worldwide. Describing in great detail both the manufacturing process and resulting module performance, the book also touches on the newest developments in this sector, such as Tunnel Oxide Passivated Contact (TOPCON) and heterojunction modules, while dedicating a major chapter to general questions of module design and fabrication. Overall, it presents the essential theoretical and practical concepts of PV solar cells and modules in an easy-to-understand manner and discusses current challenges facing the global research and development community.

Development of Materials and Structures for P-type Contacts in CdTe Solar Cells

Development of Materials and Structures for P-type Contacts in CdTe Solar Cells PDF Author: Dino Ferizovic
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The contact performance of Cu2Te thin films was comparable to that of CdTe/ZnTe superlattices and both demonstrated an advantage over contacts based on ZnTe:N thin films which were used a standard.

Coatings and Thin-Film Technologies

Coatings and Thin-Film Technologies PDF Author: Jaime Andres Perez Taborda
Publisher: BoD – Books on Demand
ISBN: 1789848709
Category : Technology & Engineering
Languages : en
Pages : 288

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Book Description
The field of coatings and thin-film technologies is rapidly advancing to keep up with new uses for semiconductor, optical, tribological, thermoelectric, solar, security, and smart sensing applications, among others. In this sense, thin-film coatings and structures are increasingly sophisticated with more specific properties, new geometries, large areas, the use of heterogeneous materials and flexible and rigid coating substrates to produce thin-film structures with improved performance and properties in response to new challenges that the industry presents. This book aims to provide the reader with a complete overview of the current state of applications and developments in thin-film technology, discussing applications, health and safety in thin films, and presenting reviews and experimental results of recognized experts in the area of coatings and thin-film technologies.

Investigation of Advanced Back Contacts for CdTe Thin Film Solar Cells

Investigation of Advanced Back Contacts for CdTe Thin Film Solar Cells PDF Author: Alireza Barati
Publisher:
ISBN:
Category : Solar cells
Languages : en
Pages : 0

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Book Description


CdTe and Related Compounds; Physics, Defects, Hetero- and Nano-structures, Crystal Growth, Surfaces and Applications

CdTe and Related Compounds; Physics, Defects, Hetero- and Nano-structures, Crystal Growth, Surfaces and Applications PDF Author:
Publisher: Elsevier
ISBN: 0080965148
Category : Science
Languages : en
Pages : 292

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Book Description
Almost thirty years after the remarkable monograph of K. Zanio and the numerous conferences and articles dedicated since that time to CdTe and CdZnTe, after all the significant progresses in that field and the increasing interest in these materials for several extremely attractive industrial applications, such as nuclear detectors and solar cells, the edition of a new enriched and updated monograph dedicated to these two very topical II-VI semiconductor compounds, covering all their most prominent, modern and fundamental aspects, seemed very relevant and useful. - Detailed coverage of the main topics associated with the very topical II-VI semiconductor compound CdTe and its alloy CZT - Review of the CdTe recent developments - Fundamental background of many topics clearly introduced and exposed

Recent Advances in Thin Film Photovoltaics

Recent Advances in Thin Film Photovoltaics PDF Author: Udai P. Singh
Publisher: Springer Nature
ISBN: 9811937249
Category : Technology & Engineering
Languages : en
Pages : 281

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Book Description
This book provides recent development in thin-film solar cells (TFSC). TFSC have proven the promising approach for terrestrial and space photovoltaics. TFSC have the potential to change the device design and produce high efficiency devices on rigid/flexible substrates with significantly low manufacturing cost. TFSC have several advantages in manufacturing compared to traditional crystalline Si-solar cells like less requirement of materials, can be prepared with earth’s abundant materials, less processing steps, easy to dispose, etc. Several universities/research institutes/industry in India and abroad are involved in the research area of thin-film solar cells. The book helps the readers to find the details about different thin-film technologies and its advancement at one place. Each chapter covers properties of materials, its suitability for PV applications, simple manufacturing processes and recent and past literature survey. The issues related to the development of high efficiency TFSC devices over large area and its commercial and future prospects are discussed.

Comprehensive Guide on Organic and Inorganic Solar Cells

Comprehensive Guide on Organic and Inorganic Solar Cells PDF Author: Md. Akhtaruzzaman
Publisher: Academic Press
ISBN: 0323858074
Category : Science
Languages : en
Pages : 420

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Book Description
Comprehensive Guide on Organic and Inorganic Solar Cells: Fundamental Concepts to Fabrication Methods is a one-stop, authoritative resource on all types of inorganic, organic and hybrid solar cells, including their theoretical background and the practical knowledge required for fabrication. With chapters rigorously dedicated to a particular type of solar cell, each subchapter takes a detailed look at synthesis recipes, deposition techniques, materials properties and their influence on solar cell performance, including advanced characterization methods with materials selection and experimental techniques. By addressing the evolution of solar cell technologies, second generation thin-film photovoltaics, organic solar cells, and finally, the latest hybrid organic-inorganic approaches, this book benefits students and researchers in solar cell technology to understand the similarities, differences, benefits and challenges of each device. Introduces the basic concepts of different photovoltaic cells to audiences from a wide variety of academic backgrounds Consists of working principles of a particular category of solar technology followed by dissection of every component within the architecture Crucial experimental procedures for the fabrication of solar cell devices are introduced, aiding picture practical application of the technology

Electrical Characterization of Thin Film CdTe Solar Cells

Electrical Characterization of Thin Film CdTe Solar Cells PDF Author: Darshini Desai
Publisher:
ISBN: 9781109861761
Category :
Languages : en
Pages : 320

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Book Description
Photovoltaic device modeling results obtained using AMPS (Analysis of microelectronic and photonic structures) suggest that the dominant recombination mechanism is the SRH recombination through midgap states.