Influence of Pressure on Contacts between Layers in Organic Photovoltaic Cells


Article Preview

This paper explored the effects of pressure on contacts between layers of organic photovoltaic cells with poly (3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) as the active layer. The contacts between the layers are modeled using analytical concepts and finite element models. The potential effects of surface roughness and dust particles are modeled along with the effects of lamination pressure and adhesion energy. The results show that, increased pressure is associated with decreased void length or increased contact length. The contacts associated with the interfaces between the active layer and the hole/electron injection layer poly (3,4-ethylenedioxythiophene: poly styrenesulphonate (PEDOT.PSS) and Molybdenum trioxide (MoO3) are also compared. The implications of the results are discussed for the design of stamping/lamination processes for the fabrication of organic photovoltaic cells.



Edited by:

Prof. Wole Soboyejo, Dr. Shola Odusunya, Dr. Zebaze Kana, Dr. Nicolas Anuku, Dr. Karen Malatesta and Dr. Mohammed Dauda




B. Agyei-Tuffour et al., "Influence of Pressure on Contacts between Layers in Organic Photovoltaic Cells", Advanced Materials Research, Vol. 1132, pp. 204-216, 2016

Online since:

December 2015




* - Corresponding Author

[1] S. B. Darling, F. You, T. D. Veselka, A. Velosa, Assumptions and the levelized cost of energy for photovoltaics, Energy and Environmental Science 4 (2011) 3133–3139.


[2] Cravino A, Schilinsky P and Brabec C J 2007Adv. Funct. Mater. 173906–10.

[3] Kim Y, Ballantyne A M, Nelson J and Bradley D C 2009 Org. Electron. 10205–9.

[4] Hains A. W and Marks T. J 2008, Appl. Phys. Lett. 9223504–6.

[5] de Jong M P, van Ijzendoorn, L. JanddeVoigt M. J. A, 2000 Appl. Phys. Lett. 772255–7.

[6] Sun N, Fang G, Qin P, Zheng Q, Wang M, Fan X, Cheng F, Wan J, Zhao X, Liu J, Carroll D L and Ye J 2010J. Phys. D: Appl. Phys. 43445101.

[7] J Kettle, H Waters, M Horie and S-W Chang, Effect of hole transporting layers on the performance of PCPDTBT : PCBM organic solar cells, 2012 J. Phys. D: Appl. Phys. 45 125102.


[8] Betancur R, Maym´M, Elias X, Vuong L T and Martorell J 2011 Sol. Energy. Mater. Sol. Cells 95735–9.

[9] H. You, Y. F. Dai, Z. Q. Zhang, D. G. Ma, Improved performances of organic light-emitting diodes with metal oxide as anode buffer, Journal of Applied Physics 101 (2007) 026105.


[10] W. J. Shin, J. Y. Lee, J. C. Kim, T. H. Yoon, T. S. Kim, O.K. Song, Bulk and interface properties of molybdenum trioxide-doped hole transporting layer in organic light-emitting diodes, Organic Electronics 9 (2008) 333–338.


[11] L. Fengmin, S. Shuyan, G. Xiaoyang, Z. Yun, X. Zhiyuan, Efficient polymer photovoltaic cells using solution-processed MoO3 as anode buffer layer, Solar Energy Materials and Solar Cells 94 (2010) 842–845.


[12] Y. M. Sun, C. J. Takacs, S. R. Cowan, J. H. Seo, X. Gong, A. Roy, A. J. Heeger, Efficient, air-stable bulk heterojunction polymer solar cells using MoO(x) as the anode interfacial layer, Advanced Materials 23 (2011) 2226–2230.


[13] J. H. Li, J. S. Huang, Y. Yang, Improved hole-injection contact for top-emitting polymeric diodes, Applied Physics Letters 90 (2007) 173505.


[14] P. R. Brown, R. R. Lunt, N. Zhao, T. P. Osedach, D.D. Wanger, L.Y. Chang, M.G. Bawendi, V. Bulovic, Improved current extraction from ZnO/PbS quantum dot heterojunction photovoltaics using a MoO3 interfacial layer, Nano Letters 11 (2011).


[15] Y. -C. Tseng, Q. Peng, L. E. Ocola, J. W. Elam, S. B. Darling, Enhanced block copolymer lithography using sequential infiltration synthesis, Journal of Physical Chemistry C 115 (2011) 17725–17729.


[16] T. Tong, B Babatope, S. Admassie, J. Meng, O. Akwogu, W. Akande and W. O. Soboyejo: Adhesion in Organic Structures, Journal of Applied Physics 106, 083708 (2009).


[17] J. M. Neumeister and W. A. Ducker. Rev. Sci. Instrum. 65, 2527 (1994).

[18] J. E. Sader, I. Larson, P. Mulvaney, L. R. White. Rev. Sci. Instrum. 66, 3789 (1995).

[19] K. L. Johnson, K. Kendall and A. D. Roberts: Surface energy and the contact of elastic solids, Proc. R. Soc. Lond. A. 324, 301-313 (1971).

[20] A. Bietsch and B. Michel: J. Appl. Physics. 88, 4310 (2000).

[21] J. A. Greenwood, Adhesion of Elastic Spheres,. Proc. R. Soc. Lond. A (1997) 453, 1277-1297.

[22] B. V. Derjaguin and V. M. Muller and Y. P. Toporov: Effect of contact deformations on the adhesion of particles, J. Colloid Interface Sci. 53 (1975) 314–325.


[23] D. Maugis and M. Barquins and R. Courtel, M ́taux: Corrosion, Industrie 605 (1976) 1.

[24] D. S. Grierson, E. E. Flater and R. W. Carpick: Accounting for the JKR–DMT transition in adhesion and friction measurements with atomic force microscopy, J. Adhesion Sci. Technol., Vol. 19, No. 3–5, p.291– 311 (2005).


[25] Y. Cao, C. Kim, S. R. Forrest, and W. Soboyejo, J. Appl. Phys. 98, 033713 (2005).

[26] W. O. Akande, Y. Cao, N. Yao, and W. Soboyejo, J. Appl. Phys. 107, 043519 (2010).

[27] J. Du, V. C. Anye, E. O. Vodah,T. Tong, M. G. Zebaze Kana and W. O. Soboyejo, Pressure-assisted fabrication of organic light emitting diodes with MoO3 hole-injection layer materials J. Appl Phys 115, 233703 (2014).


[28] International Organization for Standardization, ISO 14644-1: 1999, Cleanrooms of and Associated Controlled Environments-Part I: Classification of Air Cleanliness (ISO, Switzerland, 1999).

[29] W. M. Moreau, Semiconductor Lithography: Principles, Practices, and Materials (Plenum Press, New York, 1988).

[30] B. M. Malyshev and R. L. Salganik, Int. J. Fract. 26, 261–275 (1984).

[31] K. Wan and Y. Mai, Int. J. Fract. 74, 181–197 (1995).

[32] A. Bietsch and B. Michel, J. Appl. Phys. 88, 4310 (2000).

[33] W. Soboyejo, Mechanical Properties of Engineered Materials (CRC, New York, 2003).

[34] W. D. Callister, Materials Science and Engineering: An Introduction (Wiley, New York, 2003).

[35] Sam-Shajing Sun, Larry R. Dalton, Introduction to Organic Electronic and Optoelectronic Materials and Devices (Optical Science and Engineering) 1st Edition, pp CRC, Press, (2008).