Novel recombination lifetime mapping technique through Kelvin probe studies

Alderman, Nicholas and Danos, Lefteris and Grossel, Martin and Markvart, Tom (2013) Novel recombination lifetime mapping technique through Kelvin probe studies. In: Photovoltaic Specialists Conference (PVSC), 2013 IEEE 39th :. IEEE, USA, 0209-0211.

Abstract

The Kelvin probe is a very powerful and versatile tool, allowing the extraction of data such as diffusion length, surface photovoltage and impurity concentrations. This paper investigates the extraction of surface recombination velocities (and assuming a bulk lifetime, the surface recombination lifetime) from the I-V type dependence of the sample. By using an X-Y stage, the surface recombination lifetime can be imaged for entire wafers, instead of obtaining an average value of lifetime similar to that obtained from the Sinton WCT-120 lifetime tool. This is useful in determining where further improvements in the surface passivation can be obtained, by observing problem areas in the passivation layer.