Conformal GaP layers on Si wire arrays for solar energy applications

We report conformal, epitaxial growth of GaP layers on arrays of Si microwires. Silicon wires grown using chlorosilane chemical vapor deposition were coated with GaP grown by metal-organic chemical vapor deposition. The crystalline quality of conformal, epitaxial GaP/Si wire arrays was assessed by transmission electron microscopy and x-ray diffraction. Hall measurements and photoluminescence show p- and n-type doping with high electron mobility and bright optical emission. GaP pn homojunction diodes on planar reference samples show photovoltaic response with an open circuit voltage of 660 mV.

[1]  Nathan S. Lewis,et al.  Si microwire-array solar cells , 2010 .

[2]  Nathan S. Lewis,et al.  Energy-Conversion Properties of Vapor-Liquid-Solid–Grown Silicon Wire-Array Photocathodes , 2010, Science.

[3]  N. Lewis,et al.  10 μm minority-carrier diffusion lengths in Si wires synthesized by Cu-catalyzed vapor-liquid-solid growth , 2009 .

[4]  S. M. Oak,et al.  Effect of two-step growth process on structural, optical and electrical properties of MOVPE-grown GaP/Si , 2008 .

[5]  Nathan S. Lewis,et al.  Growth of vertically aligned Si wire arrays over large areas (>1 cm^2) with Au and Cu catalysts , 2007 .

[6]  A. Nath,et al.  Studies on MOVPE growth of GaP epitaxial layer on Si(001) substrate and effects of annealing , 2006 .

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

[8]  Daniel J. Friedman,et al.  III-N-V semiconductors for solar photovoltaic applications , 2002 .

[9]  Herbert Kroemer,et al.  Polar-on-nonpolar epitaxy , 1987 .

[10]  Y. Kao,et al.  Electron and hole carrier mobilities for liquid phase epitaxially grown GaP in the temperature range 200–550 K , 1983 .

[11]  A. A. Studna,et al.  Dielectric functions and optical parameters of Si, Ge, GaP, GaAs, GaSb, InP, InAs, and InSb from 1.5 to 6.0 eV , 1983 .

[12]  Herbert Kroemer,et al.  On the (110) orientation as the preferred orientation for the molecular beam epitaxial growth of GaAs on Ge, GaP on Si, and similar zincblende‐on‐diamond systems , 1980 .

[13]  H. Grubin.  The physics of semiconductor devices , 1979, IEEE Journal of Quantum Electronics.

[14]  H. Casey,et al.  Variation of Electrical Properties with Zn Concentration in GaP , 1969 .

[15]  P. J. Dean,et al.  Optical Properties of the Group IV Elements Carbon and Silicon in Gallium Phosphide , 1968 .

[16]  F. Trumbore,et al.  Radiative Recombination between Deep‐Donor‐Acceptor Pairs in GaP , 1965 .