Petroleum coke-derived graphene as a low-cost electrode material for efficient perovskite solar cells

We present a cost-effective approach for converting petroleum coke into high-quality graphene <i>via</i> thermal desulfurization followed by electrochemical exfoliation. The synthesized graphene exhibited structural integrity and optoelectronic properties comparable to those of graphite-derived materials. Integrated as rear electrodes in perovskite solar cells (PSCs), the petcoke-derived graphene enabled devices to achieve a power conversion efficiency (PCE) of approximately 19.1%, with an open-circuit voltage (<i>V</i> _oc) exceeding 1.13 V and a fill factor (FF) of ∼78%. The petcoke-derived graphene PSCs exhibited superior photovoltaic performance compared to those fabricated with commercial graphene, and demonstrated comparable efficiency to devices employing conventional gold electrodes. These findings highlight the potential of waste-derived graphene as a scalable, sustainable, and economically viable alternative to noble metal contacts, aligning with circular economy principles and advancing low-cost photovoltaic technologies.