OSI - One Step Interconnect for Thin Film PV Modules

Lead Research Organisation: Loughborough University
Department Name: Wolfson Sch of Mech, Elec & Manufac Eng

Abstract

The market for photovoltaic (PV) modules has expanded dramatically from 6.4GW in 2009 to 37GW in 2013. PV demand is
poised for explosive growth to reach 49GW in 2014, and is forecast to reach up to 100GW by 2018. This end-market
growth is projected to increase annual PV module revenues, which are forecast to reach US$50 billion in 2018. Despite
being severely hampered by overcapacity and declining operating margins during 2012 and 2013, the PV industry still grew
34% over this two-year period. Thin film PV has approximately a 10% market share and has inherent cost advantages,
especially in the development of utility scale installations. As part of the manufacturing process, it is necessary to
interconnect gridded areas of the PV module to form long series connected PV regions. In this project, the interconnect will
be achieved using a new laser ablation/inkjet process that works at speeds of up to 3m/sec. This will radically change the
way modules are produced by reducing complexity and cost of manufacture. The sales target for this new process is
>$10m per annum with attractive ongoing sales of specialist inks. The primary objective is to develop the OSI process and
materials for semi-transparent perovskite for Building Integrated PV glazing applications, a very promising market. The
secondary and tertiary objectives are to develop the process and materials for CIGS and CZTS, respectively.

Planned Impact

The market for solar modules has increased by 35% pa compound over the past 15 years. About 90% of solar module
production is currently based on crystalline silicon. However, second generation solar cells based on thin film technology
have an inherent advantage because less material is required for their manufacture, and with increasing efficiency, costs
are reducing rapidly. First Solar Inc, a manufacturer of thin film CdTe film photovoltaics is the world's lowest cost PV
manufacturer with costs of $0.53/Wp. The One Step Interconnect process can be applied at all thin film technologies
including CdTe, CIGS (and CZTS), a-Si and Perovskite PV.
Most thin film PV manufacturers vacuum deposit (PVD/CVD) individual layers interspersed by laser scribes across the
~1m2 panel which leads to strip like cells which overlap along the short edges to form a monolithic series interconnection. It
would be highly advantageous to re-organise the production line so that all the deposition steps are performed first by the
OSI process. This would reduce cost, reduce factory size and improve process control and efficiency. Several manufacturers have already confirmed that they would prefer to employ such technology. M-Solv and CREST at
Loughborough have pioneered such a process using a combination of selective laser scribing and inkjet deposition of
insulators and conductors. This project will address some remaining process technology issues. These include the
development of inks that can be UV or laser cured at ultra-fast rates and Intrinsiq Ltd, a specialist ink manufacturer is in the
team for this purpose. Oxford Photovoltaics Ltd is exploiting the UK's world lead in Perovskite PV and this project will
prove out the interconnection for this new PV technology and also develop a transparent conducting ink suitable for
interconnects on semi-transparent window products. The project will form a powerful UK supply chain.

Publications

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Abbas A (2015) Cadmium chloride assisted re-crystallisation of CdTe: The effect on the CdS window layer in Materials Research Society Symposium Proceedings

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Bittau F (2018) Analysis and optimisation of the glass/TCO/MZO stack for thin film CdTe solar cells in Solar Energy Materials and Solar Cells

 
Description Ways to accurately align laser ablation and inkjet tools.

Formulation of conducting and insulating inks with long life performance

Successful integration of laser ablation and inkjet printing.
Exploitation Route M-solv Ltd are commercialising the OSI process.

Dyecotec Ltd are supplying inks.

Oxford Photovoltaics Ltd are using the OSI process to interconnect their R&D modules.
Sectors Energy

 
Description The OSI process is now being commercialised. Orders for systems have been obtained from solar module manufacturers in the Far East.
First Year Of Impact 2017
Sector Energy,Manufacturing, including Industrial Biotechology
Impact Types Economic

 
Description Member of the Energy committee of the Institute of Physics
Geographic Reach National 
Policy Influence Type Participation in a advisory committee
Impact The Energy committee of the institute of Physics organises events to disseminate latest energy related research.
 
Description Member of the Ion and Plasma Surface Interactions committee of the Institute of Physics
Geographic Reach National 
Policy Influence Type Membership of a guideline committee
Impact Promotion of thin films and plasmas to improve industrial manufacturing processes
 
Description Member of the Solar commision
Geographic Reach National 
Policy Influence Type Participation in a national consultation
 
Description A National Thin-Film Cluster Facility for Advanced Functional Materials
Amount £460,998 (GBP)
Funding ID EP/M022900/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 08/2015 
End 08/2020
 
Description organic-inorganic perovskite hybrid tandem solar cells
Amount £696,405 (GBP)
Funding ID EP/M024881/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 05/2015 
End 04/2018
 
Description Development of inorganic thin film photovolaics 
Organisation U.S. Department of Energy
Department National Renewable Energy Laboratory (NREL)
Country United States 
Sector Public 
PI Contribution Joint research on solution based deposition of CIGS thin film Photovoltaics. Collaboration to understand the performance of single crystal CdTe PV devices.
Collaborator Contribution Production of single crystal devices. TRPL and confocal PL analysis.
Impact 3 Publications, 2 joint Conference papers in 2016.
Start Year 2012
 
Description Low cost solution processed solar cells using CIGS nanoparticles 
Organisation Nanoco
Country United Kingdom 
Sector Private 
PI Contribution Assessment of performance of thin film CIGS PV devices. Process development on rigid and flexible substrates. HRTEM characterisation.
Collaborator Contribution Fabrication of CIGS PV devices using nanoparticles
Impact Joint paper at the 2016 IEEE PVSC conference
Start Year 2015
 
Description NSF Industry/University Co-operative Research Center for Next Generation Photovoltaics 
Organisation Colorado State University
Country United States 
Sector Academic/University 
PI Contribution The consortium is engaged in increasing the efficiency and lowering the cost of thin film CdTe photovoltaics. We are producing thin films, complete devices and characterisation using HRTEM.
Collaborator Contribution The other partners are Colorado State University, University of Texas at Austin, First Solar Inc, 5N Plus, Direct Solar LLC, Ion Edge Corporation, NREL and MBI corporation. ECh partner is engaged in developing materials or devices.
Impact 8 Publications
Start Year 2010
 
Description OSI-One Step Interconnect for Thin Film PV Modules 
Organisation M-Solv
Country United Kingdom 
Sector Private 
PI Contribution Providing devices for testing the interconnect process. Evaluating the performance and durability of the Interconnects.
Collaborator Contribution Using laser ablation and inkjet printing to interconnect PV cells in a PV module
Impact 3 Publications. M-solv are close to commercialising the OSI process. Our industrial partners are Oxford Photovoltaics Ltd and Dycotec Ltd.
Start Year 2009
 
Title IMPROVEMENTS TO THE DEPOSITION AND FORMATION OF COATINGS FOR PHOTOVOLTAIC CELLS 
Description The invention relates to the formation of a photovoltaic or solar cell device and in particular to a coating formed on a surface of the same. The device incorporates a substrate formed by a glass base on which there is provided a transparent conductive coating (TCO). Onto a surface of the substrate or this coating there is, in accordance with the invention in one embodiment, sputter deposited a layer of CdS followed by the sputter deposition of a layer including CdTe. A back contact layer can be applied as a final layer. The CdS layer acts as the n-type layer while the CdTe containing layer acts as the p-type layer of the device. The cross section of the photovoltaic cell, and the layers provided, can be altered to suit specific requirements. For example, a buffer layer of Sn02 or ZnO can be applied onto the TCO prior to the CdS coating to improve device performance. 
IP Reference WO2018083480 
Protection Patent application published
Year Protection Granted 2018
Licensed No
Impact New method to deposit solar cells
 
Description Advances in Photovoltaics 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Meeting on 'Advances in Photovoltaics' held at the Institute of Physics. SuperSolar event with 70 attendees. International invited speakers.
Organiser and Chairman
Year(s) Of Engagement Activity 2015
 
Description Appearance on Radio Wiltshire 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Interview describing the work and success of the EPSRC Supergen SuperSolar Hub
Year(s) Of Engagement Activity 2015
 
Description Feature on Radio 4 Tonight programme. 13th February 2019 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Radio 4 feature on latest developments in Solar
Year(s) Of Engagement Activity 2019
 
Description Member of the Energy commitee of the Institute of Physics 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The Energy committee of the IOP organises events of interest to the scientific and engineering community concerned with Enery generation and use.
Year(s) Of Engagement Activity 2016,2017,2018,2019
 
Description Member of the IEEE EDS Technical Committee on Photovoltaic devices. 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The IEEE EDS Technical Committee on Photovoltaic devices.is an International body concerned with standards for photovoltaic (solar panel) modules.
Year(s) Of Engagement Activity 2019
 
Description Member of the Ion and Plasma Surface Interactions Group commitee of the Institute of Physics 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The commitee organises events for academia and industry including the annual 'Advances in Photovoltaics' meeting at the IOP.
Year(s) Of Engagement Activity 2019
 
Description Member of the Solar Commision 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact The Solar Commision has been formed to identify R&D prioriries for solar to stimulate further deployment
Year(s) Of Engagement Activity 2019