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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 900-904 |
| Number of pages | 5 |
| Journal | Microscopy and Microanalysis |
| Volume | 23 |
| Issue number | 5 |
| DOIs | |
| State | Published - Aug 15 2017 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: The authors would like to thank Eric Schneller for assistance with analysis of the quantum efficiency and reflectance data. The authors acknowledge financial support from the Australian Renewable Energy Agency (ARENA) under the Postdoctoral Fellowship. The authors would also like to acknowledge support for this work by the US Department of Energy, Office of Energy Efficiency and Renewable Energy, in the Solar Energy Technologies Program, under Award Number DE-EE0004947. Finally, the Materials Characterization Facility at University of Central Florida (UCF) is acknowledged for usage of its facilities.