Silicon Heterojunction Solar Cells
Silicon Heterojunction Solar Cells

Author: W.R. Fahrner

Publisher: Trans Tech Publications Ltd

Published: 2006-08-15

Total Pages: 208

ISBN-13: 3038131024

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The world of today must face up to two contradictory energy problems: on the one hand, there is the sharply growing consumer demand in countries such as China and India. On the other hand, natural resources are dwindling. Moreover, many of those countries which still possess substantial gas and oil supplies are politically unstable. As a result, renewable natural energy sources have received great attention. Among these, solar-cell technology is one of the most promising candidates. However, there still remains the problem of the manufacturing costs of such cells. Many attempts have been made to reduce the production costs of “conventional” solar cells (manufactured from monocrystalline silicon using diffusion methods) by instead using cheaper grades of silicon, and simpler pn-junction fabrication. That is the ‘hero’ of this book; the heterojunction solar cell.

Silicon Heterojunction Solar Cells
Silicon Heterojunction Solar Cells

Author: Wolfgang R. Fahrner

Publisher:

Published: 2006

Total Pages: 220

ISBN-13:

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The world of today must face up to two contradictory energy problems: on the one hand, there is the sharply growing consumer demand in countries such as China and India. On the other hand, natural resources are dwindling. Moreover, many of those countries which still possess substantial gas and oil supplies are politically unstable. As a result, renewable natural energy sources have received great attention. Among these, solar-cell technology is one of the most promising candidates. However, there still remains the problem of the manufacturing costs of such cells. Many attempts have been made to reduce the production costs of "conventional" solar cells (manufactured from monocrystalline silicon using diffusion methods) by instead using cheaper grades of silicon, and simpler pn-junction fabrication. That is the 'hero' of this book; the heterojunction solar cell.

Physics and Technology of Amorphous-Crystalline Heterostructure Silicon Solar Cells
Physics and Technology of Amorphous-Crystalline Heterostructure Silicon Solar Cells

Author: Wilfried G. J. H. M. van Sark

Publisher: Springer Science & Business Media

Published: 2011-11-16

Total Pages: 588

ISBN-13: 3642222757

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Today’s solar cell multi-GW market is dominated by crystalline silicon (c-Si) wafer technology, however new cell concepts are entering the market. One very promising solar cell design to answer these needs is the silicon hetero-junction solar cell, of which the emitter and back surface field are basically produced by a low temperature growth of ultra-thin layers of amorphous silicon. In this design, amorphous silicon (a-Si:H) constitutes both „emitter“ and „base-contact/back surface field“ on both sides of a thin crystalline silicon wafer-base (c-Si) where the electrons and holes are photogenerated; at the same time, a-Si:H passivates the c-Si surface. Recently, cell efficiencies above 23% have been demonstrated for such solar cells. In this book, the editors present an overview of the state-of-the-art in physics and technology of amorphous-crystalline heterostructure silicon solar cells. The heterojunction concept is introduced, processes and resulting properties of the materials used in the cell and their heterointerfaces are discussed and characterization techniques and simulation tools are presented.

Heterojunction Solar Cells (a-Si/c-Si)
Heterojunction Solar Cells (a-Si/c-Si)

Author: Thomas Mueller

Publisher: Logos Verlag Berlin GmbH

Published: 2009

Total Pages: 280

ISBN-13: 3832522913

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The main focus of the present work is related to the optimization of heterojunction solar cells. The key roles in obtaining high efficient heterojunction solar cells are mainly the plasma enhanced chemical vapor deposition of very low defect layers, and the sufficient surface passivation of all interfaces. In heterojunction solar cells, the a-Si: H/c-Si hetero-interface is of significant importance, since the hetero-interface characteristics directly affect the junction properties and thus solar cell efficiency. In this work, the deposition and film properties of various hydrogenated amorphous silicon alloys, such as a-SiC: H, a-SiO_x: H, and muc-Si: H (standard a-Si: H is used as reference), are employed. Special attention is paid to (i) the front and back surface passivation of the bulk material by high-quality wide-gap amorphous silicon suboxides (a-SiO_x: H), and (ii) the influence of wide-gap high-quality a-Si- and muc-Si-based alloys for use as emitter and back-surface-

Amorphous Silicon / Crystalline Silicon Heterojunction Solar Cells
Amorphous Silicon / Crystalline Silicon Heterojunction Solar Cells

Author: Wolfgang Rainer Fahrner

Publisher: Springer Science & Business Media

Published: 2013-04-23

Total Pages: 119

ISBN-13: 364237039X

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Amorphous Silicon/Crystalline Silicon Solar Cells deals with some typical properties of heterojunction solar cells, such as their history, the properties and the challenges of the cells, some important measurement tools, some simulation programs and a brief survey of the state of the art, aiming to provide an initial framework in this field and serve as a ready reference for all those interested in the subject. This book helps to “fill in the blanks” on heterojunction solar cells. Readers will receive a comprehensive overview of the principles, structures, processing techniques and the current developmental states of the devices. Prof. Dr. Wolfgang R. Fahrner is a professor at the University of Hagen, Germany and Nanchang University, China.

Crystalline Silicon Heterojunction Solar Cells
Crystalline Silicon Heterojunction Solar Cells

Author: Denís Pascual Sánchez

Publisher:

Published: 2015

Total Pages:

ISBN-13:

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This work is a slight research on silicon heterojunction solar cells which have been of great interest recently. The aim is to span fabrication, characterization and simulation and to reach a broad but shallow knowledge about this devices. Within heterojunction solar cells, this work is particularly focused on amorphous silicon/crystalline silicon (a-Si/c-Si) heterojunction solar cells and Transition-Metal-Oxide (TMO) silicon heterojunction solar cells (TMO/c-Si). TMO started being of interest very recently because they can substitute a-Si in a solar cell lowering fabrication costs while achieving relatively good performance. Unlikely, it is not clear why it can play the same role as a-Si since they are very different materials. Therefore simulating TMO based devices is still far from being reliable. Simulations of a-Si heterojunction solar cells have been performed since it seems to be the starting point of the road to simulating TMO. The fabrication and characterization processes are almost the same for the two types of solar cell. Since the final aim is to understand TMO heterojunction solar cells, this part is dedicated to them. Three different TMOs heterojunction solar cells have been fabricated and characterized which are M oOx , W Ox and V2 O5 while the simulation has focused on a-Si. The work has been carried out collaborating with a research group from electronics department of the UPC (Universitat Politèctica de Cataunya). Silvaco ATLAS electronic device simulator has been used to reproduce the a-Si HIT (Heterojuntion with Intrinsic Thin layer) solar cell figures of merit.

High-Efficiency Crystalline Silicon Solar Cells
High-Efficiency Crystalline Silicon Solar Cells

Author: Eun-Chel Cho

Publisher: MDPI

Published: 2021-01-06

Total Pages: 90

ISBN-13: 3039436295

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This book is composed of 6 papers. The first paper reports a novel technique for the selective emitter formation by controlling the surface morphology of Si wafers. Selective emitter (SE) technology has attracted renewed attention in the Si solar cell industry to achieve an improved conversion efficiency of passivated-emitter rear-contact (PERC) cells. In the second paper, the temperature dependence of the parameters was compared through the PERC of the industrial-scale solar cells. As a result of their analysis, PERC cells showed different temperature dependence for the fill factor loss as temperatures rose. The third paper reports the effects of carrier selective front contact layer and defect state of hydrogenated amorphous silicon passivation layer/n-type crystalline silicon interface. The results demonstrated the effects of band offset determined by band bending at the interface of the passivation layer and carrier selective front contact layer. In addition, the nc-SiOx: H CSFC layer not only reduces parasitic absorption loss but also has a tunneling effect and field-effect passivation. The fourth paper reports excimer laser annealing of hydrogenated amorphous silicon film for TOPCon solar cell application. This paper analyzes the crystallization of a-Si:H via excimer laser annealing (ELA) and compared this process with conventional thermal annealing. The fifth paper reports the contact mechanism between Ag–Al and Si and the change in contact resistance (Rc) by varying the firing profile. Rc was measured by varying the belt speed and peak temperature of the fast-firing furnace. The sixth paper reports a silicon tandem heterojunction solar cell based on a ZnO/Cu2O subcell and a c-Si bottom subcell using electro-optical numerical modeling. The buffer layer affinity and mobility together with a low conduction band offset for the heterojunction are discussed, as well as spectral properties of the device model.

Physics and Technology of Amorphous-Crystalline Heterostructure Silicon Solar Cells
Physics and Technology of Amorphous-Crystalline Heterostructure Silicon Solar Cells

Author: Wilfried G. J. H. M. van Sark

Publisher: Springer

Published: 2012-02-23

Total Pages: 582

ISBN-13: 9783642222764

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Today’s solar cell multi-GW market is dominated by crystalline silicon (c-Si) wafer technology, however new cell concepts are entering the market. One very promising solar cell design to answer these needs is the silicon hetero-junction solar cell, of which the emitter and back surface field are basically produced by a low temperature growth of ultra-thin layers of amorphous silicon. In this design, amorphous silicon (a-Si:H) constitutes both „emitter“ and „base-contact/back surface field“ on both sides of a thin crystalline silicon wafer-base (c-Si) where the electrons and holes are photogenerated; at the same time, a-Si:H passivates the c-Si surface. Recently, cell efficiencies above 23% have been demonstrated for such solar cells. In this book, the editors present an overview of the state-of-the-art in physics and technology of amorphous-crystalline heterostructure silicon solar cells. The heterojunction concept is introduced, processes and resulting properties of the materials used in the cell and their heterointerfaces are discussed and characterization techniques and simulation tools are presented.

Toward Better Understanding and Improved Performance of Silicon Heterojunction Solar Cells
Toward Better Understanding and Improved Performance of Silicon Heterojunction Solar Cells

Author:

Publisher:

Published: 2004

Total Pages: 0

ISBN-13:

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The double-sided silicon heterojunction (SHJ) solar cell is more appropriate for n-type crystal silicon (c-Si) wafers than for p-type c-Si wafers because there is a larger band offset to the valence band edge of hydrogenated amorphous silicon than to the conduction band edge. Thin intrinsic and doped hydrogenated amorphous silicon (a Si:H) double layers by hot-wire chemical vapor deposition (HWCVD) are investigated as passivation layers, emitters, and back-surface-field (BSF) contacts to both p- and n-type wafers. Passivation quality is studied by characterizing the SHJ solar cells and by photoconductive decay (PCD) minority-carrier lifetime measurements. The crystal-amorphous heterointerface is studied with real-time spectroscopic ellipsometry (RTSE) and high-resolution transmission electron microscopy (HRTEM) to detect phase change and material evolution, with a focus on better understanding the factors determining passivation effectiveness. A common feature in effective passivation, emitter, and BSF layers is immediate a-Si:H deposition and an abrupt and flat interface to the c-Si substrate. In this case, good wafer passivation or an excellent heterojunction is obtained, with a low interface recombination velocity (S) or a high open-circuit voltage (Voc). Voc greater than 640 mV, S less than 15 cm/sec, and efficiency of 14.8% have been achieved on polished p type Czochralski-grown (CZ) Si wafers. Collaboration between NREL and Georgia Tech resulted in a 15.7%-efficient HWCVD-deposited SHJ cell on non-textured FZ-Si with a screen-printed Al back surface field (BSF), the highest reported HWCVD SHJ cell. Collaboration between NREL and SunPower demonstrated that HWCVD a-Si:H passivation can be better than the conventional oxides, with a low surface recombination velocity of 42 cm/sec on textured n-type FZ-Si.