Silica nanospheres as back surface reflectors for crystalline silicon thin‐film solar cells

In this paper, fabrication of a non-continuous silicon dioxide layer from a silica nanosphere solution followed by the deposition of an aluminium film is shown to be a low-cost, low-thermal-budget method of forming a high-quality back surface reflector (BSR) on crystalline silicon (c-Si) thin-film solar cells. The silica nanosphere layer has randomly spaced openings which can be used for metal-silicon contact areas. Using glass/SiN/p + nn + c-Si thin-film solar cells on glass as test vehicle, the internal quantum efficiency (IQE) at long wavelengths (>900 nm) is experimentally demonstrated to more than double by the implementation of this BSR, compared to the baseline case of a full-area Al film as BSR. The improved optical performance of the silica nanosphere/aluminium BSR is due to reduced parasitic absorption in the Al film.

[1]  Armin G. Aberle,et al.  Progress with polycrystalline silicon thin-film solar cells on glass at UNSW , 2006 .

[2]  Jane F. Bertone,et al.  Single-Crystal Colloidal Multilayers of Controlled Thickness , 1999 .

[3]  Paul A. Basore,et al.  Pilot production of thin-film crystalline silicon on glass modules , 2002, Conference Record of the Twenty-Ninth IEEE Photovoltaic Specialists Conference, 2002..

[4]  R. Iler,et al.  Multilayers of colloidal particles , 1966 .

[5]  Armin G. Aberle,et al.  Surface passivation of crystalline silicon solar cells: a review , 2000 .

[6]  Arjun G. Yodh,et al.  ENTROPIC COLLOIDAL INTERACTIONS IN CONCENTRATED DNA SOLUTIONS , 1998 .

[7]  Younan Xia,et al.  Monodispersed Colloidal Spheres: Old Materials with New Applications , 2000 .

[8]  M. Green,et al.  24·5% Efficiency silicon PERT cells on MCZ substrates and 24·7% efficiency PERL cells on FZ substrates , 1999 .

[9]  Polycrystalline silicon thin‐film solar cells on glass by aluminium‐induced crystallisation and subsequent ion‐assisted deposition (ALICIA) , 2005 .

[10]  D. A. Clugston,et al.  Crystalline silicon on glass (CSG) thin-film solar cell modules , 2004 .

[11]  Nils-Peter Harder,et al.  Laser structuring for back junction silicon solar cells , 2007 .

[12]  A. Aberle,et al.  Commercial white paint as back surface reflector for thin-film solar cells , 2007 .

[13]  Paul A. Basore,et al.  Numerical modeling of textured silicon solar cells using PC-1D , 1990 .

[14]  Y. Chabal,et al.  Chemomechanical polishing of silicon: Surface termination and mechanism of removal , 1994 .

[15]  M. Heyns,et al.  Removal of Submicrometer Particles from Silicon Wafer Surfaces Using HF-Based Cleaning Mixtures , 2001 .

[16]  P. Campbell.  Light trapping and reflection control in a crystalline silicon solar cell , 1990 .