Silicon nanowire solar cells with a-Si heterojunction showing 7.3% efficiency

Core-shell silicon nanowire (SiNW) solar cells with an a-Si heterojunction were prepared on SiNW arrays, which were etched into n-type silicon wafers or into n-doped multicrystalline silicon thin films on glass substrates. A stack of intrinsic and p-doped hydrogenated a-Si was deposited as a shell around the SiNWs by PECVD, acting as a heteroemitter of the solar cells. Finally a TCO layer consisting of aluminum doped zinc oxide was deposited on top of the a-Si by atomic layer deposition. In a mesa-structured solar cell (area 7 mm2) an open circuit voltage of 476 mV and an efficiency of 7.3% were achieved under AM 1.5 illumination. Electron beam induced current measurements show clear evidence that most of the photo-current comes from the thin SiNW layer.

[1]  Martin Steglich,et al.  Core–shell heterojunction solar cells on silicon nanowire arrays , 2012 .

[2]  D. Antoniadis,et al.  Vertically arrayed Si nanowire/nanorod-based core-shell p-n junction solar cells , 2010 .

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

[4]  K. Hane,et al.  Broadband antireflection gratings fabricated upon silicon substrates. , 1999, Optics letters.

[5]  Makoto Tanaka,et al.  Development of New a-Si/c-Si Heterojunction Solar Cells: ACJ-HIT (Artificially Constructed Junction-Heterojunction with Intrinsic Thin-Layer) , 1992 .

[6]  R. S. Wagner,et al.  VAPOR‐LIQUID‐SOLID MECHANISM OF SINGLE CRYSTAL GROWTH , 1964 .

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

[8]  N. Brookes,et al.  Direct quantification of gold along a single Si nanowire. , 2008, Nano letters.

[9]  A. Gawlik,et al.  Silicon nanowire-based solar cells on glass: synthesis, optical properties, and cell parameters. , 2009, Nano letters.

[10]  D. Lang,et al.  Complex nature of gold-related deep levels in silicon , 1980 .

[11]  M. Taguchi,et al.  Development status of high-efficiency HIT solar cells , 2011 .

[12]  Yasuroh Iriye,et al.  Anisotropic etching rates of single-crystal silicon for TMAH water solution as a function of crystallographic orientation , 1999 .

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

[14]  J. Rand,et al.  Silicon Nanowire Solar Cells , 2007 .

[15]  W. Benecke,et al.  NH4Oh-based etchants for silicon micromachining , 1990 .

[16]  B. To,et al.  Efficient heterojunction solar cells on p-type crystal silicon wafers , 2010 .

[17]  Integrated silicon nanowire diodes and the effects of gold doping from the growth catalyst , 2007 .

[18]  Yunjie Yan,et al.  Synthesis of Large‐Area Silicon Nanowire Arrays via Self‐Assembling Nanoelectrochemistry , 2002 .

[19]  Peng Wang,et al.  High-resolution detection of Au catalyst atoms in Si nanowires. , 2008, Nature nanotechnology.

[20]  H. Fujiwara,et al.  Effects of a‐Si:H layer thicknesses on the performance of a‐Si:H∕c‐Si heterojunction solar cells , 2007 .

[21]  D. Borchert,et al.  Preparation of (n) a-Si: H/(p) c-Si heterojunction solar cells , 1997 .

[22]  Chito Kendrick,et al.  Enhanced conversion efficiencies for pillar array solar cells fabricated from crystalline silicon with short minority carrier diffusion lengths , 2010 .

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

[24]  Bozhi Tian,et al.  Single and tandem axial p-i-n nanowire photovoltaic devices. , 2008, Nano letters.

[25]  Ning-Bew Wong,et al.  Precision-Cut Crystalline Silicon Nanodots and Nanorods from Nanowires and Direct Visualization of Cross Sections and Growth Orientations of Silicon Nanowires , 2003 .