Trap density imaging of silicon wafers using a lock-in infrared camera technique

verfasst von

Peter Pohl, Jan Schmidt, Karsten Bothe, Rolf Brendel

Abstract

We apply a novel an imaging technique for nonrecombination active minority-carrier trapping centres in silicon wafers based on lock-in infrared thermography. Measurements on Czochralski silicon wafers show that the trap density is highly inhomogenous and correlates with oxygen-induced striation patterns. A direct comparison of the trap density image with the corresponding recombination lifetime mapping reveals an anticorrelation of the two quantities. The application of the ITM technique to block-cast multicrystalline silicon wafers shows that the distribution of the trapping centres correlates with the dislocation density. Moreover, we find that areas with increased dislocation density often degrade during phosphorus gettering treatment. Finally, we demonstrate that one single spatially resolved measurement of the infrared emission signal of as-delivered multicrystalline silicon without surface passivation layers reveals already poorly-getterable areas, which decrease the solar cell efficiency. Hence, trap density imaging is a useful new instrument for assessing the efficiency potential of asdelivered mc-Si wafers.

Externe Organisation(en)

Institut für Solarenergieforschung GmbH (ISFH)

Typ

Aufsatz in Konferenzband

Seiten

932-935

Anzahl der Seiten

4

Publikationsdatum

2006

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Erneuerbare Energien, Nachhaltigkeit und Umwelt, Elektrotechnik und Elektronik, Elektronische, optische und magnetische Materialien, Werkstoffchemie

Ziele für nachhaltige Entwicklung

SDG 7 – Erschwingliche und saubere Energie

Elektronische Version(en)

https://doi.org/10.1109/WCPEC.2006.279609 (Zugang: Geschlossen)