Novel Inline Deposition System for High Performance CIGS Solar Cells

Lead Research Organisation: Loughborough University
Department Name: Electronic, Electrical & Systems Enginee

Abstract

CIGS (copper indium gallium sellenide) solar cell structures have been identified as technologically important for the next generation of solar power production. They offer the advantages of being substantially less expensive to produce than crystalline devices and offer higher efficiencies than other non-crystalline photovoltaic materials. Currently, CIGS solar cells are typically produced using three separate deposition systems - two for the electrical contacts and one for the CIGS layer. The project aims to eliminate the requirement for three separate systems by combining all the processes into one system. This offers two important advantages that will ultimately result in the improved competitiveness of the process; the initial capital equipment cost will be lower than for three individual vacuum deposition systems and the inline nature of the system will allow higher throughput than conventional batch systems. The system will also demonstrate the proof of concept for roll-to-roll coating and continuous throughput systems. In addition to the manufacturing advantages described above the system will be used extensively by the experienced CIGS development team at CREST (Centre for Renewable Energy Systems), Loughborough University will develop novel high efficiency CIGS cell structures / further increasing the competitiveness of CIGS technology in comparison to mainstream energy sources. The process developement for high performance CIGS would be established through the available expertise with the PI at Loughborough along with its experienced team in standardising the procedure for commercial CIGS production through an integrated vaccum deposition system approach. The depostion and characterisation of different material layers of the device is another important aspect that will also be done at various stages of its development through the existing materials characterisation facilities at Loughborough. Finally the finished device resulting out of the system will be tested for its performance using the existing faciltities at CREST on small as well as large area (minimodule) CIGS devices, for which laser scribing as well standard large area module testing Solar simulators are available at place.

Publications

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Description Currently, CIGS solar cells are typically produced using three separate deposition systems - two for the electrical contacts and one for the CIGS layer. The in-line system successfully designed and developed under the project fullfills the requirement for three separate systems by combining all the processes into one system. This offers two important advantages that will ultimately result in the improved competitiveness of the process; the initial capital equipment cost will be lower than for three individual vacuum deposition systems and the inline nature of the system will allow higher throughput than conventional batch systems.
The system, capable of developing 30cm x 30cm CIGS modules on glass will also be able to demonstrate the proof of concept for roll-to-roll coating and continuous throughput systems on glass as well as flexible substrates, which will be planned for the second phase of the research program. In addition to the manufacturing advantages described above the system will be used extensively by the experienced CIGS development team at CREST (Centre for Renewable Energy Systems Technology), Loughborough University who are currently optimising the process towards the development of high efficiency CIGS cell structures through an integrated vaccum deposition system approach, further increasing the competitiveness of CIGS technology in comparison to mainstream energy sources.
The process developement for high performance CIGS would be established through the available expertise with the PI at Loughborough along with its experienced team in standardising the procedure for commercial CIGS production The deposition and characterisation of different material layers viz. good quality CdS using chemcial bath deposition method, rf sputtered ZnO:Al with ~6 Ohm/sq. sheet resistance with ~85% transmission along with good quality Molybdenum on glass using dc sputtering have been successfully achieved, along with advanced trails on CIGS layer and compositions for high efficiency CIGS is underway. through the existing materials characterisation facilities at Loughborough.
Finally the efficient and optimised devices resulting out of the system will be tested for its performance using the existing faciltities at CREST on small as well as large area (minimodule) CIGS devices. Further, there is already a plan for these large area devices which will be laser scribed for interconnects in collaboration with another company M-Solv for a feasibility study leading to finsihed efficient module production strategy in future.
Exploitation Route The novel design of the CIGS solar cells development using in-line pilot system for high performance 3-stage evaporation process will be able to generate good quality CIGS absorbers. The hallmark of this design is the use of local heating of the substrate which can translate from one region of the chamber to another using robotic arm. This feature can allow nearly all the layers of the solar cells viz. back Mo and front TCO contact including absorber and buffer layers without breaking the vacuum.
The manufacturers like TSMC have shown interests in this design. Currently, the system is being optimised for high efficiency CIGS with about 10% efficiency achieved at initial trials and will be aimed for a state-of-the-art level of performance in the future.
Sectors Energy

Manufacturing

including Industrial Biotechology

URL http://www.sciencedirect.com/science/article/pii/S0257897213009675
 
Description The success of this project has led to a finished in-line high performance CIGS deposition system (Quantum 2010, as marketed by industry partner SVS Ltd). The initial studies conducted on this machine have resulted over 10% efficient solar cell even under unoptimised conditions, resulted a PhD degree of the student involved in this development and study. Recently, the company SVS Ltd. is planning to loan this machine to Brunel University to conduct research to achieve state of the art efficiencies ~20% for its commercial gains as this machine can deliver 30cm x 30cm large area solar panel for integration with buildings. It has also attracted commercial interests of a company called W2E based in France, who wish to collaborate with the PI and the industry SVS Ltd.
First Year Of Impact 2011
Sector Energy,Environment,Manufacturing, including Industrial Biotechology
Impact Types Economic