A Predictive Optical Simulation Model for the Rear-Surface Roughness of Passivated Silicon Solar Cells

In this paper, we introduce a predictive, physics-based model, i.e., the so-called tilted-mirror model (tm-model), for optical modeling of rough rear surfaces on silicon solar cells. An enhanced method of using transfer matrices at the rear-side interface of solar cells is developed and combined with Monte Carlo ray tracing. As a result, a physically consistent and precise simulation of the spectral reflectance is achieved, thus leading to a predictive quality of the simulations that could previously not be reached for solar cells with a remaining irregular rear-surface roughness. This advance in optical simulation enables the researcher to directly analyze the effects of varying rear-side passivation materials and thicknesses, as well as the impact of different surface morphologies on the gained charge-carrier generation rate of a solar cell. A comparison with the Phong model shows that the tm-model is able to simulate the generated photocurrent Jph more accurately, as it is shown that the Phong model tends to overestimate this value due to imprecise calculation of charge-carrier generation. In an application of the tm-model to passivated emitter and rear cells, it is shown that a strong planarization of the rear surface leads to an improvement in photogenerated current up to 0.13 mA/cm2 compared with a weak planarization.

[1]  T. Ohzone,et al.  Numerical solar cell simulation including multiple diffused reflection at the rear surface , 2000 .

[2]  D. Biro,et al.  Recombination and Optical Properties of Wet Chemically Polished Thermal Oxide Passivated Si Surfaces , 2013, IEEE Journal of Photovoltaics.

[3]  H. Macleod,et al.  Thin-Film Optical Filters , 1969 .

[4]  Ralf Preu,et al.  Surface passivation of crystalline silicon by plasma-enhanced chemical vapor deposition double layers of silicon-rich silicon oxynitride and silicon nitride , 2011 .

[5]  Keith R. McIntosh,et al.  One‐dimensional photogeneration profiles in silicon solar cells with pyramidal texture , 2012 .

[6]  F BlinnJames.  Models of light reflection for computer synthesized pictures , 1977 .

[7]  M. Green,et al.  Optical properties of intrinsic silicon at 300 K , 1995 .

[8]  Martin A. Green,et al.  Self-consistent optical parameters of intrinsic silicon at 300 K including temperature coefficients , 2008 .

[9]  Keith R. McIntosh,et al.  Reflection distributions of textured monocrystalline silicon: implications for silicon solar cells , 2012 .

[10]  Bernhard Fischer,et al.  Loss analysis of crystalline silicon solar cells using photoconductance and quantum efficiency measurements , 2003 .

[11]  A. Rakić,et al.  Algorithm for the determination of intrinsic optical constants of metal films: application to aluminum. , 1995, Applied optics.

[12]  K. McIntosh,et al.  Reflection of normally incident light from silicon solar cells with pyramidal texture , 2011 .

[13]  Stefan W. Glunz,et al.  Theory and experiments on the back side reflectance of silicon wafer solar cells , 2008 .

[14]  M. Green,et al.  22.8% efficient silicon solar cell , 1989 .

[15]  James F. Blinn,et al.  Models of light reflection for computer synthesized pictures , 1977, SIGGRAPH.

[16]  Bui Tuong Phong.  Illumination for computer generated pictures , 1975, Commun. ACM.