Property Investigation of a-Si/c-Si Hetero-Junction Structure

Abstract

Abstract: This paper investigated the influence of a-Si/c-Si band offset, amorphous silicon emitter doping concentration and interface defects density on interface property of a-Si/c-Si structure. Band offset in a-Si(N+)/c-Si(P) hetero-junction and a-Si emitter high level doping is very useful for the transformation of recombination mechanism from dangling bond to SRH(Shockly-Read-Hall). AFORS-HET simulation indicates that a-Si(N+) emitter doping level of over 1.5×1020 cm-3 on c-Si(P) is an indispensable condition for achieving high efficiency. Comparing with density of short circuit current, open circuit voltage of a-Si/c-Si structure cell is much more susceptible to interface defect density.

Key words: amorphous silicon/crystal silicon, emitter doping, interface defect density(Dit)

CLC Number:

TM914.4

WANG Jian-Qiang-1, 2 , GAO Hua-2, ZHANG Jian-2, ZHANG Song-1, LI Chen-1, YE Qing-Hao-1, MENG Fan-Ying-1. Property Investigation of a-Si/c-Si Hetero-Junction Structure[J]. Journal of Shanghai Jiaotong University, 2011, 45(06): 798-803.

References

［1］Pankove J I,Tarng M L. Amorphous silicon as a passivation for crystalline silicon［J］.Appl Phys Lett,1979, 34(2): 156157.

［2］Kerr M J, Cuevas A. Very low bulk and surface recombination in oxidized silicon wafers［J］. Semiconductor Science and Technology,2002, 17(1): 3538.

［3］Yablonovitch E, Swanson R M, Eades W D, et al. Electronhole recombination at the SiSiO2 interface［J］. Appl Phys Lett,1986, 48(3): 245247.

［4］Glunz S W, Biro D, Rein S, et al. Fieldeffect passivation of the SiO2Si interface［J］.J App Phys, 1999,86(1): 683691.

［5］Aberle A G, Glunz S, Warta W. Impact of illumination level and oxide parameters on ShockleyReadHall recombination at the Si/SiO2 interface［J］.J App Phys,1992, 71(2): 44224431.

［6］Aberle A G. Crystalline silicon solar cells: Advanced surface passivation and analysis［M］. Sydney: Bridge Printery, 1999.

［7］Hezel R, Schorner R, Meisel T. Application of amorphous silicon nitride for MIS/inversion layer solar cells［C］//Proc 3rd EPVSEC. Cannes:［s.n.］, 1980: 866870.

［8］Hezel R, Schorner R. Plasma Si nitride——A promising dielectric to achieve highquality silicon MIS/IL solar cells［J］. J App Phys, 1981,52(4):30763079.

［9］Biegelsen D K, Johnson N M, Stutzmann M, et al. Native defects at the Si/SiO2 interfaceamorphous silicon revisited［J］. Applications of Surface Science,1985, 22/23: 879890.

［10］Zhao L. Design optimization of bifacial HIT solar cells on ptype silicon substrates by simulation［J］.Solar Energy Materials & Solar Cells,2008,92: 673681.

［11］May S G, Sze S M. Fundamentals of semiconductor fabrication［M］.New York:John Wiley & Sons, 2003.

［12］Hubin J, Shah A V, Sauvain E. Effects of dangling bonds on the recombination function in amorphous semiconductors［J］.Philosophical Magazine Letters,1992, 66(3): 115125.

［13］Yablonovitch E, Gmitter T. Auger recombination in silicon at low carrier densities［J］. Appl Phys Lett,1986, 49(10): 587589.

［14］Razouk R R, Deal B E. Dependence of interface state density on silicon thermal oxidation process variables［J］.Journal of the Electrochemical Society, 1979,126(9): 15731581.

［15］Schuurmans F M, Schonecker A, Eikelboom J A, et al. Crystalorientation dependence of surface recombination velocity for silicon nitride passivated silicon wafers［C］//Proc 25th IEEE PVSEC.Washington DC, USA: IEEE, 1996: 485488.

［16］DeWolf S, Beaucarne G.Surface passivation properties of borondoped plasmaenhanced chemical vapor deposited hydrogenated amorphous silicon films on ptype crystalline Si substrates［J］. Appl Phys Lett, 2006, 88: 022104.

［17］Garin M, Rau U, Brendle W, et al. Characterization of aSi:H/cSi interfaces by effectivelifetime measurements［J］. J App Phys, 2005, 98: 093711.

［18］Anderson R L. Experiments on GeGaAs heterojunctions［J］. SolidState Electronics,1962, 5: 341351.

［19］Kleider J P, Gudovskikh A S, Cabarrocas P R. Determination of the conduction band offset between hydrogenated amorphous silicon and crystalline silicon from surface inversion layer conductance measurements［J］.Appl Phys Lett, 2008, 92: 162101.

［20］Van de Walle C G, Yang L H. Band discontinuities at heterojunctions between crystalline and amorphous silicon［J］. J Vac Sci Technol, 1995, B13: 16351638.