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Golden, CO, United States

Bolen M.L.,National Renewable Energy Laboratory | Grover S.,National Renewable Energy Laboratory | Teplin C.W.,National Renewable Energy Laboratory | Bobela D.,Ampulse Corporation | And 2 more authors.
Conference Record of the IEEE Photovoltaic Specialists Conference | Year: 2012

Post-deposition hydrogenation by remote plasma significantly improves performance of heteroepitaxial silicon (Si) solar cells. Heteroepitaxial deposition of thin crystal Si on sapphire for photovoltaics (PV) is an excellent model system for developing the PV technology platform of film c-Si on inexpensive Al2O3-coated (100) biaxially-textured metal foils. Without hydrogenation PV conversion efficiencies are less than 1% in our model system, due to carrier recombination at electrically-active dislocations and other growth defects. Hydrogenation dramatically improves performance, with low-temperature hydrogenation at 350oC being more effective than hydrogenation at 610°C. Spectral quantum efficiency, secondary ion mass spectrometry (SIMS), and vibrational Si-Hx Raman spectroscopy measurements elucidate the effects of hydrogenation on the materials and devices. Quantum efficiency increases at wavelengths >400 nm, indicating hydrogenation is mostly affecting the bulk of the cells. SIMS detects nearly 100 times more hydrogen atoms in our cells than available dangling bonds along all dislocations. Yet, Raman spectroscopy indicates that only low temperature hydrogenation creates Si-Hx bonds; trapped hydrogen does not stably passivate dangling-bond recombination sites at high temperatures. © 2012 IEEE. Source


Grant
Agency: National Science Foundation | Branch: | Program: STTR | Phase: Phase I | Award Amount: 149.94K | Year: 2010

This Small Business Technology Transfer (STTR) Phase I project aims to develop roll-to-roll processing of highly efficient, thin film photovoltaics on inexpensive polycrystalline substrates. The innovation lies in an architecture that yields near-single-crystalline thin films even on polycrystalline substrates. This innovation will be combined with the benefits of hot wire chemical vapor deposition (HWCVD) for Si film deposition. A key objective of this project is to demonstrate a high-rate HWCVD process for epitaxial Si layer on single-crystalline-like templates to fabricate high-efficiency solar cells on metal substrates. A strong emphasis will be placed on minimizing sources of defects and developing a comprehensive understanding of the impacts of these parameters on structural, electronic and photovoltaic properties of epitaxial thin film heterostructures. The broader/commercial impact of this project will be the potential to provide a viable solution that enables high efficiency and low manufacturing cost without using scarce materials in Photovoltaics devices. In addition to commercial potential, a strong understanding of the mechanisms of epitaxial growth, grain boundaries, and defect generation and propagation is expected to be derived from this work.


Grant
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 149.94K | Year: 2010

This Small Business Technology Transfer (STTR) Phase I project aims to develop roll-to-roll processing of highly efficient, thin film photovoltaics on inexpensive polycrystalline substrates. The innovation lies in an architecture that yields near-single-crystalline thin films even on polycrystalline substrates. This innovation will be combined with the benefits of hot wire chemical vapor deposition (HWCVD) for Si film deposition. A key objective of this project is to demonstrate a high-rate HWCVD process for epitaxial Si layer on single-crystalline-like templates to fabricate high-efficiency solar cells on metal substrates. A strong emphasis will be placed on minimizing sources of defects and developing a comprehensive understanding of the impacts of these parameters on structural, electronic and photovoltaic properties of epitaxial thin film heterostructures.

The broader/commercial impact of this project will be the potential to provide a viable solution that enables high efficiency and low manufacturing cost without using scarce materials in Photovoltaics devices. In addition to commercial potential, a strong understanding of the mechanisms of epitaxial growth, grain boundaries, and defect generation and propagation is expected to be derived from this work.


Trademark
Ampulse Corporation | Date: 2010-07-01

Electrical apparatus and instruments for the generation and transformation of electrical energy from photovoltaic and/or solar sources, namely, photovoltaic solar modules, solar wafers made of silicon and solar panels.


Trademark
Ampulse Corporation | Date: 2010-07-01

Electrical apparatus and instruments for the generation and transformation of electrical energy from photovoltaic and/or solar sources, namely, photovoltaic solar modules, solar wafers made of silicon and solar panels.

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