Extraction of contact resistivity for a partial contact solar cell

Abstract

Partial contacts are used in solar cells and other electronic devices. The contact resistivity and contact resistance of these partial contacts play a significant role in the performance optimization of these devices. In this work, we propose a strategy for accurate extraction of the partial contact resistivity (ρ_PC) of a solar cell with Ohmic (or linear) and Schottky (or non-linear) contacts. We demonstrate how the Cox-Strack Method (CSM) can accurately estimate the ρ_PC of a solar cell using Sentaurus TCAD-based simulations. Our simulation predicts that for linear contact solar cells, ρ_PC is approximately constant when the contact fraction is varied, whereas for non-linear contact, ρ_PC decreases with contact fraction as opposed to the previously reported works. The experimentally reported data is also shown to support the claim for the linear contacts further. Despite the larger full-contact resistivity of non-linear contacts, the contact resistivity and fill factor (FF) of both linear and non-linear partial contact solar cell is almost similar to ~(3.5- 5) mΩ cm^(-2) and ~75% respectively at a 0.3% contact fraction. This is attributed to the reduction in contact resistivity for non-linear contacts with contact fraction. We finally show the generality of this study for any contact material system. This work can be applied to any device with partial contacts.