TY - JOUR
T1 - 10 μm minority-carrier diffusion lengths in Si wires synthesized by Cu-catalyzed vapor-liquid-solid growth
AU - Putnam, Morgan C.
AU - Turner-Evans, Daniel B.
AU - Kelzenberg, Michael D.
AU - Boettcher, Shannon W.
AU - Lewis, Nathan S.
AU - Atwater, Harry A.
N1 - Funding Information:
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.
PY - 2009
Y1 - 2009
N2 - The effective electron minority-carrier diffusion length, Ln,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, Ln,eff was limited by surface recombination to a value of 0.7 μm. However, a value of Ln,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 Ln,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.
AB - The effective electron minority-carrier diffusion length, Ln,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, Ln,eff was limited by surface recombination to a value of 0.7 μm. However, a value of Ln,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 Ln,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.
UR - http://www.scopus.com/inward/record.url?scp=70350431281&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70350431281&partnerID=8YFLogxK
U2 - 10.1063/1.3247969
DO - 10.1063/1.3247969
M3 - Article
AN - SCOPUS:70350431281
VL - 95
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 16
M1 - 163116
ER -