Title:	Graphene-Based Transparent Electrode Incorporated into Silicon Heterojunction Solar Cell Technology
Author(s):	I. Torres, S. Fernández, J.J. Gandía, N. González Peñalba, R. Barrio Martin, M. de la Cruz, J. Cárabe
Keywords:	Contact, Heterojunction, ITO, TCO Transparent Conducting Oxides
Topic:	Silicon Materials and Cells
Subtopic:	Low Temperature Route for Si Cells
Event:	37th European Photovoltaic Solar Energy Conference and Exhibition
Session:	2DV.3.4
Pages:	478 - 481
ISBN:	3-936338-73-6
Paper DOI:	10.4229/EUPVSEC20202020-2DV.3.4
Price:	0,00 EUR
Document(s):	paper, poster

Abstract/Summary:

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Silicon heterojunction (SHJ) solar cell technology surely exhibit impressive efficiencies. However, it is often seen examples of devices that are held back by the fill factor (FF). In this work, we present graphene as a viable solution to improve the electrical characteristics of the transparent conductive electrodes based on indium tin oxide (ITO) and thus increase the device’ FF. For this study, single-layer graphene sheets were transferred onto the ITO surface of a SHJ solar cell prior to the metal grid deposition. Simultaneously, graphene sheets were also transferred onto ITO films deposited onto glass substrates for optical and electrical characterization. We show how a single graphene layer has little impact on the optical characteristics of the ITO layer while showing a clear electrical improvement. Applied to a solar cell, the improved electrical properties translates into a 28% reduction to the cell’ series resistance and to a 2.6% improvement in the measured FF, confirming hybrid electrodes based on ITO and graphene as a valid approach to further improve the FF of SHJ solar cells.