Multijunction single-crystal CdTe-based solar cells: opportunities and challenges

Sivalingam Sivananthan; James W. Garland; Michael W. Carmody

doi:10.1117/12.852599

28 April 2010 Multijunction single-crystal CdTe-based solar cells: opportunities and challenges

Sivalingam Sivananthan, James W. Garland, Michael W. Carmody

Proceedings Volume 7683, Energy Harvesting and Storage: Materials, Devices, and Applications; 76830N (2010) https://doi.org/10.1117/12.852599
Event: SPIE Defense, Security, and Sensing, 2010, Orlando, Florida, United States

Abstract

Solar energy is the only renewable energy source that could largely replace the burning of fossil fuels and is the most rapidly deployable energy source, but because of its high cost, makes up only 1% of the world's energy production. Concentrated photovoltaics (CPV) requires the least land and by far the least semiconductor material of any photovoltaic technology, but is the most expensive. Its high cost arises from the need to approximately lattice match the substrate and III-V materials in the three-junction CPV solar cells to maximize minority-carrier recombination times and hence cell efficiencies. Lattice-matching forces the use of Ge substrates, which are very expensive and fragile, making the cells very expensive. We give experimental evidence and theoretical arguments that, unlike III-V cells, CdTe-based multijunction cells need not be lattice-matched and could be grown on Si by high-throughput molecular beam epitaxy, reducing the cost an order of magnitude. That would allow the use of much lower solar concentrations, greatly reducing the tracking and optics costs. Also, efficiency calculations, assuming lattice matching not to be required for II-VI materials, indicate that the highest-efficiency three-junction II-VI cells should have efficiencies 3-8% (absolute) higher than those of the highest-efficiency three-junction III-V cells. We have fabricated and tested single-junction and twojunction CdZnTe/Si solar cells, concentrating on the value of the open-circuit voltage Voc because it measures the absorber-material limitations on cell efficiencies. We found V_oc ≥ 90% of its thermodynamic limit, equivalent to the best reported results for single-junction III-V cells.

Citation Download Citation

Sivalingam Sivananthan, James W. Garland, and Michael W. Carmody "Multijunction single-crystal CdTe-based solar cells: opportunities and challenges", Proc. SPIE 7683, Energy Harvesting and Storage: Materials, Devices, and Applications, 76830N (28 April 2010); https://doi.org/10.1117/12.852599

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available