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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. [email protected]
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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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