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Abstract
In this paper, after describing the basics of lock-in thermography investigations of solar cells, the application of this imaging technique for the characterisation of silicon wafer-based solar cells is reviewed. In particular, the differences between various variants of this technique working with and without light illumination are discussed. It is found that, for imaging and a detailed local investigation of leakage currents, both under forward and reverse bias, the application of dark lock-in thermography is most useful. On the other hand, illuminated lock-in thermography provides some unique possibilities, like the investigation of shunts in non-metallised solar cells or without contacting the cells, local efficiency imaging, and the imaging of the local avalanche multiplication factor under reverse bias. A special variant of illuminated lock-in thermography enables the imaging of the minority carrier lifetime distribution and of trapping centres in bare silicon wafers.
Keywords
References
- 1. (2000). ‘Lifetime mapping of Si wafers by an infrared camera’. in Proc. 28th IEEE Photovoltaics Specialists Conference, Anchorage 2000. USA, 99-103 Google Scholar
- 2. (2000). ‘Shunts due to laser scribing of solar cells evaluated by highly sensitive locl-in thermography’. Solar Energy Materials & Solar Cells. 65, 1–4, 55-62 Google Scholar
- 3. (2004). ‘Shunt types in crystalline silicon solar cells’. Progress Photovolt: Res. Appl.. 12, 7, 529-538 Google Scholar
- 4. (2005). ‘Electrothermal simulation of a defect in a solar cell’. Journal of Applied Physics. 97, 7, 074905 Google Scholar
- 5. (2008). ‘Imaging physical parameters of pre-breakdown sites by lock-in thermography techniques’. Prog. Photovolt: Res. Appl.. 16, 8, 679-685 Google Scholar
- 6. (2010). Lock-in Thermography - Basics and Use for Evaluating Electronic Devices and Materials (Second Edition). Heidelberg/New York:Springer Google Scholar
- 7. (2011a). ‘Can luminescence imaging replace lock-in thermography on solar cells?’. IEEE Journal of Photovoltaics. 1, 2, 159-167 Google Scholar
- 8. (2011b). ‘Understanding junction breakdown in multicrystalline solar cells’. Journal of Applied Physics. 109, 7, 071101 Google Scholar
- 9. (2011). ‘Nondestructive local analysis of current-voltage characteristics of solar cells by lock-in thermography’. Solar Energy Materials & Solar Cells. 95, 10, 2933-2936 Google Scholar
- 10. (2012). ‘Local efficiency analysis of solar cells based on lock-in thermography’. Solar Energy Materials & Solar Cells. 107, 381-389 Google Scholar
- 11. (2007). ‘In-line shunt detection in solar cells by fast lock-in infrared thermography’. in Proc. 22nd Photovolt. Solar Energy Conference’. Milan, Italy, 1975-1978 Google Scholar
- 12. (2012). ‘Zellproduktion 2011 (in german)’. Photon 4/2012. 42-63 Google Scholar
- 13. (1988). ‘Phase-locked image acquisition in thermography’. SPIE. 1004, 41 Google Scholar
- 14. (2001). Theory and Practice of Infrared Technology for Nondestructive Testing. New York:Wiley Google Scholar
- 15. (2008). ‘Correlation between spatially resolved solar cell efficiency and carrier lifetime of multicrystalline silicon’. J. Mat. Sci: Mater. Electron.. 19, 19, S4-S8 Google Scholar
- 16. (2001). ‘Carrier density and lifetime imaging of silicon wafers by infrared lock-in thermography’. in Proc. 17th Eur. Photovoltaic Solar Energy Conference, Munich 2001. Germany, 1597-1599 Google Scholar
- 17. (2006). ‘Determination of spatially resolved trapping parameters in silicon with injection dependent carrier density imaging’. Journal of Applied Physics. 99, 11, 114908 Google Scholar
- 18. (1990). ‘Hot spots and heavily dislocated regions in multicrystalline silicon cells’. in Proc. 21rd IEEE Photovoltaics Specialists Conference. Kissimee, USA, 800-805 Google Scholar
- 19. (1966). ‘Avalanche breakdown voltages of abrupt and linearly graded p-n junctions in Ge, Si, GaAs, and GaP’. Applied Physics Letters. 8, 5, 111-113 Google Scholar
