Analytic description of the impact of grain boundaries on Voc

Published

June 26, 2017

Author(s)

Paul M. Haney, Benoit H. Gaury

Abstract

The impact of grain boundaries on the performance of polycrsytalline photovoltaics remains an open question. We present a simplified description of dark grain boundary recombination current. The dark current takes the form of a diode equation, and the model provides closed form expressions for the reverse saturation current and ideality factor in terms of grain boundary and system parameters. This model applies under conditions relevant for thin film photovoltaics such as CdTe, namely for $p$-type absorbers with reasonably high bulk hole mobility, positively charged grain boundaries with high defect density, and grains which are not fully depleted. The dark recombination current can be used to predict the open circuit voltage for a given short circuit density, providing a simple closed form expression which shows how grain boundaries impact $V_{\rm oc}$.

Proceedings Title

44th IEEE Photovoltaic specialist conference

Conference Dates

June 26-30, 2017

Conference Location

Washington, DC

Pub Type

Conferences

Download Paper

https://doi.org/10.1109/PVSC.2017.8366296

Citation

Haney, P. and Gaury, B. (2017), Analytic description of the impact of grain boundaries on Voc, 44th IEEE Photovoltaic specialist conference, Washington, DC, [online], https://doi.org/10.1109/PVSC.2017.8366296 (Accessed October 17, 2025)