Sulfur passivation and contact methods for GaAs nanowire solar cells

The effect of sulfur passivation on core-shell p-n junction GaAs nanowire (NW) solar cells has been investigated. Devices of two types were investigated, consisting of indium tin oxide contact dots or opaque Au finger electrodes. Lateral carrier transport from the NWs to the contact fingers was achieved via a p-doped GaAs surface conduction layer. NWs between the opaque contact fingers had sidewall surfaces exposed for passivation by sulfur. The relative cell efficiency increased by 19% upon passivation. The contribution of the thin film grown between the NWs to the total cell efficiency was estimated by removing the NWs using a sonication procedure. Mechanisms of carrier transport and photovoltaic effects are discussed on the basis of spatially resolved laser scanning measurements.

[1]  S. T. Lee,et al.  Vertically aligned p-type single-crystalline GaN nanorod arrays on n-type Si for heterojunction photovoltaic cells. , 2008, Nano letters.

[2]  E. Bakkers,et al.  Surface passivated InAs/InP core/shell nanowires , 2010 .

[3]  M. Zervos.  Properties of the ubiquitous p–n junction in semiconductor nanowires , 2008 .

[4]  Martin Heiss,et al.  Impact of surfaces on the optical properties of GaAs nanowires , 2010 .

[5]  P. Werner,et al.  Photovoltaic Properties of p-Doped GaAs Nanowire Arrays Grown on n-Type GaAs(111)B Substrate , 2009, Nanoscale research letters.

[6]  Zongfu Yu,et al.  Semiconductor nanowire optical antenna solar absorbers. , 2010, Nano letters.

[7]  Ray R. LaPierre,et al.  Numerical model of current-voltage characteristics and efficiency of GaAs nanowire solar cells , 2011 .

[8]  P. Pehrsson,et al.  Surface depletion effects in semiconducting nanowires , 2008 .

[9]  Peidong Yang,et al.  Silicon nanowire radial p-n junction solar cells. , 2008, Journal of the American Chemical Society.

[10]  Nathan S. Lewis,et al.  Comparison of the device physics principles of planar and radial p-n junction nanorod solar cells , 2005 .

[11]  Charles M. Lieber,et al.  Coaxial silicon nanowires as solar cells and nanoelectronic power sources , 2007, Nature.

[12]  E. Bakkers,et al.  Increase of the photoluminescence intensity of InP nanowires by photoassisted surface passivation. , 2005, Journal of the American Chemical Society.

[13]  D. Thompson,et al.  GaAs core--shell nanowires for photovoltaic applications. , 2009, Nano letters.

[14]  C. Thelander,et al.  Sulfur passivation for ohmic contact formation to InAs nanowires , 2007 .

[15]  T. Fukui,et al.  Growth of Core–Shell InP Nanowires for Photovoltaic Application by Selective-Area Metal Organic Vapor Phase Epitaxy , 2009 .

[16]  G. Eftekhari.  Electrical properties of sulfur-passivated III–V compound devices , 2002 .

[17]  Ray R. LaPierre,et al.  GaP/GaAsP/GaP core–multishell nanowire heterostructures on (111) silicon , 2007 .

[18]  Peidong Yang,et al.  Light trapping in silicon nanowire solar cells. , 2010, Nano letters.

[19]  Gang Chen,et al.  Analysis of optical absorption in silicon nanowire arrays for photovoltaic applications. , 2007, Nano letters.