Putnam, Morgan C. and Turner-Evans, Daniel B. and Kelzenberg, Michael D. and Boettcher, Shannon W. and Lewis, Nathan S. and Atwater, Harry A. (2009) 10 µm minority-carrier diffusion lengths in Si wires synthesized by Cu-catalyzed vapor-liquid-solid growth. Applied Physics Letters, 95 (16). Art. No. 163116. ISSN 0003-6951 http://resolver.caltech.edu/CaltechAUTHORS:20091119-144726009
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The effective electron minority-carrier diffusion length, L_(n,eff), for 2.0 µm diameter Si wires that were synthesized by Cu-catalyzed vapor-liquid-solid growth was measured by scanning photocurrent microscopy. In dark, ambient conditions, L_(n,eff) was limited by surface recombination to a value of ≤ 0.7 µm. However, a value of L_(n,eff) = 10.5±1 µm was measured under broad-area illumination in low-level injection. The relatively long minority-carrier diffusion length observed under illumination is consistent with an increased surface passivation resulting from filling of the surface states of the Si wires by photogenerated carriers. These relatively large L_(n,eff) values have important implications for the design of high-efficiency, radial-junction photovoltaic cells from arrays of Si wires synthesized by metal-catalyzed growth processes.
|Additional Information:||© 2009 American Institute of Physics. Received 5 August 2009; accepted 18 September 2009; published 23 October 2009. The authors thank BP, the Department of Energy Office of Basic Energy Sciences, and the Caltech Center for Sustainable Energy Research for support, as well as the Kavli Nanoscience Institute at Caltech, the Molecular Materials Research Center at Caltech, and the Center for the Science of Materials and Engineering NSF MRSEC: DMR 0520565 for use of facilities, and thank Emily Warren, Josh Spurgeon, Brendan Kayes, and Michael Filler for their contributions.|
|Group:||Kavli Nanoscience Institute|
|Subject Keywords:||carrier lifetime, catalysis, copper, elemental semiconductors, optical microscopy, photovoltaic cells, silicon, surface recombination, surface states, wires|
|Classification Code:||PACS: 72.20.Jv; 73.20.At|
|Official Citation:||10 µm minority-carrier diffusion lengths in Si wires synthesized by Cu-catalyzed vapor-liquid-solid growth Morgan C. Putnam, Daniel B. Turner-Evans, Michael D. Kelzenberg, Shannon W. Boettcher, Nathan S. Lewis, and Harry A. Atwater, Appl. Phys. Lett. 95, 163116 (2009), DOI:10.1063/1.3247969|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||08 Dec 2009 18:20|
|Last Modified:||26 Dec 2012 11:34|
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