Performance optimization in gate-tunable Schottky junction solar cells with a light transparent and electric-field permeable graphene mesh on n-Si

Gate-tunable Schottky junction solar cells (SJSCs) based on graphene and graphene mesh electrodes on n-type Si are fabricated and the effect of the external gate voltage (V-g) on the photovoltaic characteristics is investigated. The power conversion efficiencies (PCEs) of both devices continuously increase with increasing absolute values of V-g. Importantly, despite the slightly lower PCE values at V-g = 0 V, the graphene mesh on Si SJSC shows more rapid enhancement of PCE values, from 5.7% to 8.1%, with V-g varied from 0 V to -1 V. The finite element simulation highlights the benefits of the graphene mesh electrodes from the non-uniform and dynamic modulation of potential distributions driven correlatively by a work function change in the graphene regions and electric-field penetration through the hole regions.