Tailor the Rheological Properties of Silver Front Side Metallization Paste for Crystalline Silicon Solar Cells

Abstract:

The paper aims to provide the methods to tailor the rheological properties of silver paste for improving the fine line printing properties for crystalline silicon solar cells. The investigation on the internal structure model of silver paste was performed in order to understand the interaction among constituents in silver paste. Much stronger polymer network structure is formed through chain entanglements between thixotropic agent and polymer resin compared with the network structure originated from thixotropic agent. Silver particles have some association with above polymer network structure and form a stronger internal structure of silver paste together. The rheological properties were improved by tailoring the composition of polymer resin, using a combination of controlled flocculating dispersing additive and thixotropic agent, and the addition of nanosized carbon black. The strength of internal network structure can be enhanced by the design of polymer resin composition but without increasing high shear-rate viscosity. Through the combination use of controlled flocculating dispersing additive and thixotropic agent, the strength of network structure and viscosity can be improved. The depletion flocculation induced by the addition of nanosized carbon black introduces a new attraction force between silver particles and strengthens the internal network structure.

• Periodical: Materials Science Forum (Volume 956)
• Pages: 12-20
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.956.12
• Online since: June 2019
• Authors: Jun Qin*, Wei Jun Zhang, Jin Chao Yang, Guangbao Du, Xinan Cai
• Keywords: Controlled Flocculating Dispersing Additive, Nanosized Carbon Black, Polymer Resin Composition, Printing Properties, Rheological Properties, Silver Paste, Solar Cells

References

[1] J.W. Phair, F.J. Kaiser, Determination and assessment of the rheological properties of pastes for screen printing ceramics, Annual Transactions of the Nordic Rheology Society. 17 (2009) 5.

[2] J.W. Phair, M. Lundberg, A. Kaiser, Leveling and thixotropic characteristics of concentrated zirconia inks for screen-printing, Rheol. Acta. 48 (2009) 121-133.

DOI: 10.1007/s00397-008-0301-4

[3] M.M. Hilali, S. Sridharan, C. Khadilkar, A. Shaikh, A. Rohatgi, S. Kim, Effect of Glass Frit Chemistry on the Physical and Electrical Properties of Thick-Film Ag Contacts for Silicon Solar Cells, J. electron. Mater. 35 (2006) 2041-2047.

DOI: 10.1007/s11664-006-0311-x

[4] J.T. Tsai, S.T. Lin, Silver powder effectiveness and mechanism of silver paste on silicon solar cells, J. Alloy. Compd. 548 (2013) 105-109.

DOI: 10.1016/j.jallcom.2012.09.018

[5] M. Eberstein, H. Falk-Windisch, M. Peschel, J. Schilm, T. Seuthe, M. Wenzel, C. Kretzschmar, U. Partsch, Sintering and Contact Formation of Glass Containing Silver Pastes, Energ. Proced. 27 (2012) 522-530.

DOI: 10.1016/j.egypro.2012.07.104

[6] K.K. Hong, S.B. Cho, J.S. You, J.W. Jeong, S.M. Bea, J.Y. Hua, Mechanism for the formation of Ag crystallites in the Ag thick-film contacts of crystalline Si solar cells, Sol. Energ. Mat. Sol. C. 93 (2009) 898-904.

DOI: 10.1016/j.solmat.2008.10.021

[7] C.P. Hsu, R.H. Guo, C.C. Hua, C.L. Shih, W.T. Chen, T.I. Chang, Effect of polymer binders in screen printing technique of silver pastes, J. Polym. Res. 20 (2013) 1-8.

DOI: 10.1007/s10965-013-0277-3

[8] J. Zhang, Y. Cui, H. Wang, Optimization of viscosity and thixotropy for organic medium to achieve high photovoltaic conversion efficiency of silicon solar cells, J. Renew. Sustain. Ener. 5(2013) 023117.

DOI: 10.1063/1.4796201

[9] M. Kolb, R. Botet, R. Jullien, Scaling of kinetically growing clusters, Phys. Rev. Lett. 51 (1983) 1123.

DOI: 10.1103/physrevlett.51.1123

[10] P. Meakin, Formation of fractal clusters and networks by irreversible diffusion-limited aggregation, Phys. Rev. Lett. 51 (1983) 1119.

DOI: 10.1103/physrevlett.51.1119

[11] W.Y. Shih, I.A. Aksay, R. Kikuchi, Reversible-growth model: Cluster-cluster aggregation with finite binding energies, Phys. Rev. A. 36 (1987) 5015.

DOI: 10.1103/physreva.36.5015

[12] J.W. Phair, Rheological Analysis of Concentrated Zirconia Pastes with Ethyl Cellulose for Screen Printing SOFC Electrolyte Films, J. Am. Ceram. Soc. 91 (2008) 2130–2137.

DOI: 10.1111/j.1551-2916.2008.02443.x

[13] S. Murakami, K. Ri, T. Itoh, N. Izu, W. Shin, K. Inukai, Y. Takahashi, Y. Ando, Effects of ethyl cellulose polymers on rheological properties of (La,Sr)(Ti,Fe)O3-terpineol pastes for screen printing, Ceram. Int. 40 (2014) 1661-1666.

DOI: 10.1016/j.ceramint.2013.07.057

[14] M.R. Somalu, N.P. Brandon, Rheological Studies of Nickel/Scandia-Stabilized-Zirconia Screen Printing Inks for Solid Oxide Fuel Cell Anode Fabrication, J. Am. Ceram. Soc. 95 (2012) 1220–1228.

DOI: 10.1111/j.1551-2916.2011.05014.x