Impact of localized regions with very high series resistances on cell performance

Abstract

ABSTRACT The J–V curves recorded under illumination for solar cells having a high series resistance can appear shunted when a fraction of the cell area is affected by very high series resistance values. This “apparent shunting” behaviour was observed in n‐type rear‐junction, laser‐doped cells with light‐induced plated front contacts. Localized series resistance measurements of the affected cells by photoluminescence imaging revealed that over 20% of the cell area had a series resistance above 10 Ω cm 2 and extending up to a maximum value of 168 Ω cm 2 . It was found that cells with localized series resistances have a detrimental impact on the FF and J sc of the device. Furthermore, an unusual FF recovery was also observed with decreasing level of illumination. A solar cell model with localized high series resistances was developed to further study this “apparent shunting” behaviour with respect to its impact on cell performance. Copyright © 2011 John Wiley & Sons, Ltd.