Publication Date:
2010-01-09
Description:
Silicon wire arrays, though attractive materials for use in photovoltaics and as photocathodes for hydrogen generation, have to date exhibited poor performance. Using a copper-catalyzed, vapor-liquid-solid-growth process, SiCl4 and BCl3 were used to grow ordered arrays of crystalline p-type silicon (p-Si) microwires on p+-Si(111) substrates. When these wire arrays were used as photocathodes in contact with an aqueous methyl viologen(2+/+) electrolyte, energy-conversion efficiencies of up to 3% were observed for monochromatic 808-nanometer light at fluxes comparable to solar illumination, despite an external quantum yield at short circuit of only 0.2. Internal quantum yields were at least 0.7, demonstrating that the measured photocurrents were limited by light absorption in the wire arrays, which filled only 4% of the incident optical plane in our test devices. The inherent performance of these wires thus conceptually allows the development of efficient photovoltaic and photoelectrochemical energy-conversion devices based on a radial junction platform.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Boettcher, Shannon W -- Spurgeon, Joshua M -- Putnam, Morgan C -- Warren, Emily L -- Turner-Evans, Daniel B -- Kelzenberg, Michael D -- Maiolo, James R -- Atwater, Harry A -- Lewis, Nathan S -- New York, N.Y. -- Science. 2010 Jan 8;327(5962):185-7. doi: 10.1126/science.1180783.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Kavli Nanoscience Institute and Beckman Institute, 1200 East California Boulevard, California Institute of Technology, Pasadena, CA 91125, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20056886" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
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Chemistry and Pharmacology
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Computer Science
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Medicine
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Natural Sciences in General
,
Physics
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