Carbon electrodes (CEs) are demonstrated as the most stable and cost-effective back electrodes for perovskite solar cells (PSCs), which influence the performance of related PSCs significantly. Herein, oxygen-rich activated carbon (AC) is synthesized from the most abundant biomass resource, cellulose, via a feasible carbonization and oxidization process and applied in CEs for hole-conductor-free printable mesoscopic PSCs (p-MPSCs). The obtained cellulose-based activated carbon (CAC) exhibits a high specific area of 477.14 m² g⁻¹ and possesses a high oxygen content of 11.9%, promoting the wettability and contact between CEs and perovskites. Moreover, the high oxygen content also leads to an elevated work function of CEs. As a result, p-MPSCs filled with (5-AVA)_0.03(MA)_0.97PbI₃ based on CEs containing CAC give an efficiency of 15.5%, whereas those devices based on CEs with no CAC give an efficiency of 13.8%. The improved efficiency benefits from the promoted fill factor and open circuit voltage due to the optimized energy level alignment and enhanced charge extraction by CAC. This work presents a good example for the value-added utilization of cellulose in the energy conversion systems and offers a feasible strategy for preparing oxygen-rich CE for PSCs with enhanced performance.

中文翻译：

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用于可印刷介观钙钛矿太阳能电池的纤维素基富氧活性炭

碳电极（CEs）被证明是钙钛矿太阳能电池（PSCs）最稳定和最具成本效益的背电极，它显着影响了相关PSCs的性能。在此，富氧活性炭 (AC) 由最丰富的生物质资源纤维素，通过可行的碳化和氧化过程合成，并应用于 CE 中，用于无空穴导体的可印刷介观 PSC (p-MPSC)。获得的纤维素基活性炭（CAC）表现出477.14 m ²  g ^-1的高比表面积和11.9%的高氧含量，促进了CE与钙钛矿之间的润湿性和接触。此外，高氧含量还导致 CE 的功函数升高。结果，p-MPSCs 填充了 (5-AVA) _0.03(MA)基于含有 CAC 的 CE 的_0.97 PbI ₃的效率为 15.5%，而基于不含 CAC 的 CE 的那些设备的效率为 13.8%。由于优化的能级对齐和增强的 CAC 电荷提取，提高的效率受益于提升的填充因子和开路电压。这项工作为纤维素在能量转换系统中的增值利用提供了一个很好的例子，并为制备具有增强性能的 PSC 的富氧 CE 提供了可行的策略。