Several economical and eco-friendly bio-carbon electrodes for highly efficient perovskite solar cells

One of the major problems limits the applications of perovskite solar cells (PSCs) is the high cost of hole transporting materials (HTMs) and noble metallic electrodes. For HTMs and noble-metal-free PSCs, carbon materials have been utilized as counter electrodes (CEs). In this paper, four kinds of ultra-low-cost bio-carbon materials have been applied and compared in PSCs. Results showed that the photovoltaic performance of PSCs based on different bio-carbon CEs was determined by the interfacial connection, work function (WF), sheet resistance, crystallinity, and morphology of these bio-carbons. The high PCE (12.82%) of PSCs based on bio-carbon CEs has been achieved in current state-of-the-art. PSCs based on bio-carbon CEs was more stable than that of conventional devices, which could retain 87% of their initial PCE after storing for 2000 h in room temperature. Our work proposes a new pathway for the exploration of low-cost bio-carbon materials and could accelerate the applications of PSCs based on carbon electrode.