title: Charged grain boundaries reduce the open-circuit voltage of polycrystalline solar cells-An analytical description.
abstract: Analytic expressions are presented for the dark current-voltage relationJ(V) of apn+junction with positively charged columnar grain boundaries with high defect density. These expressions apply to non-depleted grains with sufficiently high bulk hole mobilities. The accuracy of the formulas is verified by direct comparison to numerical simulations. Numerical simulations further show that the darkJ(V) can be used to determine the open-circuit potentialVocof an illuminated junction for a given short-circuit current densityJsc. A precise relation between the grain boundary properties andVocis provided, advancing the understanding of the influence of grain boundaries on the efficiency of thin film polycrystalline photovoltaics like CdTe and Cu(In,Ga)Se2.
authors.affiliation: Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA; Maryland NanoCenter, University of Maryland, College Park, MD 20742, USA.
authors.forename: Benoit
authors.initials: B
authors.lastname: Gaury
authors.affiliation: Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Haney