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Transmission Electron Microscopy Studies of Electron-Selective Titanium Oxide Contacts in Silicon Solar Cells

Published online by Cambridge University Press:  15 August 2017

Haider Ali ,
Xinbo Yang ,
Klaus Weber ,
Winston V. Schoenfeld  and
Kristopher O. Davis
Haider Ali*
Affiliation:
Department of Materials Science and Engineering, University of Central Florida, 12760 Pegasus Drive, Engineering I, Suite 207, Orlando, FL 32816, USA Florida Solar Energy Center, University of Central Florida, 1679 Clearlake Rd, Cocoa, FL 32922, USA c-Si Division, U.S. Photovoltaic Manufacturing Consortium, 12354 Research Parkway, Suite 210, Orlando, FL 32826, USA
Xinbo Yang
Affiliation:
Research School of Engineering, Engineering Building 32, North Road, The Australian National University, ACT 0200, North Rd, Acton ACT 2601, Canberra, Australia KAUST Solar Center (KSC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
Klaus Weber
Affiliation:
Research School of Engineering, Engineering Building 32, North Road, The Australian National University, ACT 0200, North Rd, Acton ACT 2601, Canberra, Australia
Winston V. Schoenfeld
Affiliation:
Department of Materials Science and Engineering, University of Central Florida, 12760 Pegasus Drive, Engineering I, Suite 207, Orlando, FL 32816, USA Florida Solar Energy Center, University of Central Florida, 1679 Clearlake Rd, Cocoa, FL 32922, USA c-Si Division, U.S. Photovoltaic Manufacturing Consortium, 12354 Research Parkway, Suite 210, Orlando, FL 32826, USA CREOL, The College of Optics & Photonics, University of Central Florida, 4304 Scorpius St, Orlando, FL 32816, USA
Kristopher O. Davis
Affiliation:
Florida Solar Energy Center, University of Central Florida, 1679 Clearlake Rd, Cocoa, FL 32922, USA c-Si Division, U.S. Photovoltaic Manufacturing Consortium, 12354 Research Parkway, Suite 210, Orlando, FL 32826, USA
*
*Corresponding author. alihaider@knights.ucf.edu
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Abstract

In this study, the cross-section of electron-selective titanium oxide (TiO2) contacts for n-type crystalline silicon solar cells were investigated by transmission electron microscopy. It was revealed that the excellent cell efficiency of 21.6% obtained on n-type cells, featuring SiO2/TiO2/Al rear contacts and after forming gas annealing (FGA) at 350°C, is due to strong surface passivation of SiO2/TiO2 stack as well as low contact resistivity at the Si/SiO2/TiO2 heterojunction. This can be attributed to the transformation of amorphous TiO2 to a conducting TiO2−x phase. Conversely, the low efficiency (9.8%) obtained on cells featuring an a-Si:H/TiO2/Al rear contact is due to severe degradation of passivation of the a-Si:H upon FGA.

Keywords

TiO2electron-selective contactcrystalline siliconsolar cell
Type
Materials Science Applications
Information
Microscopy and Microanalysis , Volume 23 , Issue 5 , October 2017 , pp. 900 - 904
Copyright
© Microscopy Society of America 2017 

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References

Avasthi, S., McClain, W.E., Man, G., Kahn, A., Schwartz, J. & Sturm, J.C. (2013). Hole-blocking titanium-oxide/silicon heterojunction and its application to photovoltaics. Appl Phys Lett 102(20), 203901.Google Scholar
Battaglia, C., de Nicolás, S.M., De Wolf, S., Yin, X., Zheng, M., Ballif, C. & Javey, A. (2014 a). Silicon heterojunction solar cell with passivated hole selective MoOx contact. Appl Phys Lett 104(11), 113902.CrossRefGoogle Scholar
Battaglia, C., Yin, X., Zheng, M., Sharp, I.D., Chen, T., McDonnell, S., Azcatl, A., Carraro, C., Ma, B., Maboudian, R., Wallace, R.M. & Javey, A. (2014 b). Hole selective MoOx contact for silicon solar cells. Nano Lett 14(2), 967–971.Google Scholar
Bivour, M., Macco, B., Temmler, J., Kessels, W.M.M. & Hermle, M. (2016). Atomic layer deposited molybdenum oxide for the hole-selective contact of silicon solar cells. Energy Procedia 92, 443–449.Google Scholar
Bivour, M., Reichel, C., Hermle, M. & Glunz, S.W. (2012). Improving the a-Si:H(p) rear emitter contact of n-type silicon solar cells. Sol Energ Mat Sol Cells 106, 11–16.CrossRefGoogle Scholar
Bivour, M., Temmler, J., Steinkemper, H. & Hermle, M. (2015). Molybdenum and tungsten oxide: High work function wide band gap contact materials for hole selective contacts of silicon solar cells. Sol Energ Mater Sol Cells 142, 34–41.Google Scholar
Bullock, J., Cuevas, A., Allen, T. & Battaglia, C. (2014 a). Molybdenum oxide MoOx: A versatile hole contact for silicon solar cells. Appl Phys Lett 105(23), 232109.Google Scholar
Bullock, J., Cuevas, A., Samundsett, C., Yan, D., McKeon, J. & Wan, Y. (2015). Simple silicon solar cells featuring an a-Si:H enhanced rear MIS contact. Sol Energ Mater Sol Cells 138, 22–25.Google Scholar
Bullock, J., Yan, D., Wan, Y., Cuevas, A., Demaurex, B., Hessler-Wyser, A. & De Wolf, S. (2014 b). Amorphous silicon passivated contacts for diffused junction silicon solar cells. J Appl Phys 115(16), 163703.Google Scholar
Cox, R.H. & Strack, H. (1967). Ohmic contacts for GaAs devices. Solid State Electron 10(12), 1213–1218.CrossRefGoogle Scholar
De Wolf, S., Descoeudres, A., Holman, Z.C. & Ballif, C. (2012). High-efficiency silicon heterojunction solar cells: A review. Green 2(1), 7–24.CrossRefGoogle Scholar
Feldmann, F., Simon, M., Bivour, M., Reichel, C., Hermle, M. & Glunz, S.W. (2014). Carrier-selective contacts for Si solar cells. Appl Phys Lett 104(18), 181105.Google Scholar
Gerling, L.G., Mahato, S., Morales-Vilches, A., Masmitja, G., Ortega, P., Voz, C., Alcubilla, R. & Puigdollers, J. (2016). Transition metal oxides as hole-selective contacts in silicon heterojunctions solar cells. Sol Energ Mater Sol Cells 145, 109–115.CrossRefGoogle Scholar
Heng, J.B., Fu, J., Kong, B., Chae, Y., Wang, W., Xie, Z., Reddy, A., Lam, K., Beitel, C., Liao, C., Erben, C., Huang, Z. & Xu, Z. (2015). >23% high-efficiency tunnel oxide junction bifacial solar cell with electroplated Cu gridlines. IEEE J Photovolt 5(1), 82–86.CrossRefGoogle Scholar
Kim, D.Y., Guijt, E., van Swaaij, R.A.C.M.M. & Zeman, M. (2015). Development of a-SiOx:H solar cells with very high Voc × FF product. Prog Photovolt, 23(6), 671–684.CrossRefGoogle Scholar
Klett, J., Ziegler, J., Radetinac, A., Kaiser, B., Schafer, R., Jaegermann, W., Urbain, F., Becker, J.-P., Smirnov, V. & Finger, F. (2016). Band engineering for efficient catalyst-substrate coupling for photoelectrochemical water splitting. Phys Chem Chem Phys 18(16), 10751–10757.Google Scholar
Peter Seif, J., Descoeudres, A., Filipič, M., Smole, F., Topič, M., Charles Holman, Z., De Wolf, S. & Ballif, C. (2014). Amorphous silicon oxide window layers for high-efficiency silicon heterojunction solar cells. J Appl Phys 115(2), 024502.CrossRefGoogle Scholar
Schneller, E., Öğütman, K., Guo, S., Schoenfeld, W.V. & Davis, K.O. (2017). Crystalline silicon device loss analysis through spatially resolved quantum efficiency measurements. IEEE J Photovolt 7(4), 957–965.CrossRefGoogle Scholar
Yang, X., Bi, Q., Ali, H., Davis, K., Schoenfeld, W.V. & Weber, K. (2016 a). High-performance TiO2-based electron-selective contacts for crystalline silicon solar cells. Adv Mater 28(28), 5891–5897.CrossRefGoogle ScholarPubMed
Yang, X., Zheng, P., Bi, Q. & Weber, K. (2016 b). Silicon heterojunction solar cells with electron selective TiOx contact. Sol Energ Mater Sol Cells 150, 32–38.Google Scholar