Abstract

Perovskite solar cells (PSCs) are emerging efficient photovoltaic devices, with record-high power conversion efficiencies (PCE) of more than 25.5%. However, PSCs exhibit some drawbacks, such as poor stability upon exposure to moisture or humidity, ultraviolet (UV) radiation and heat, which in turn limits the device lifetime and performance. In addition, the introduction of perovskite films comes with associated toxicity, which is a major environmental concern. Furthermore, the application of titanium dioxide (TiO₂) as an electron transport layer (ETL) and 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (spiro-OMeTAD) as a hole transport layer (HTL), causes device instability. The wide-bandgap characteristic of TiO₂ introduces charge carrier recombination in the ETL, which, in turn, impairs device performance. This is, over and above, the high cost of spiro-OMeTAD, coupled with its multi-step synthetic preparation method. To address the aforementioned shortcomings, approaches, such as modifying the interfacial architecture, have been explored by introducing versatile materials between the charge-collecting electrode and the perovskite active layers. In this regard, perovskite oxides are more appealing due to their wide bandgap and high electron mobility. However, perovskite oxides have limitations due to their agglomeration, which causes short-circuits and leakage current, in addition to their poor charge separation efficiency, surface hydrophilicity and weak visible-light absorption. As a result, nanocomposites of perovskite oxides with carbon-based materials, particularly graphene and its derivatives, have attracted significant research attention due to their exceptional optoelectronic properties, superior stability, and non-toxicity of graphene-based materials. Therefore, this review discusses the recent trends in graphene-based materials, their composites with perovskite oxides, effective ETLs or HTLs of PSCs and the subsequent improvement of photovoltaic performance. In addition, a summary of synthetic routes for perovskite oxides/graphene nanocomposites is presented. This review will foster the advancement of the fabrication of PSCs with improved PCE and stability.

摘要

钙钛矿太阳能电池 (PSC) 是新兴的高效光伏设备，其功率转换效率 (PCE) 超过 25.5%，创历史新高。然而，PSC 存在一些缺点，例如在暴露于湿气或湿气、紫外线 (UV) 辐射和热量时稳定性差，这反过来又限制了器件的使用寿命和性能。此外，钙钛矿薄膜的引入伴随着毒性，这是一个主要的环境问题。此外，二氧化钛 (TiO ₂ ) 作为电子传输层 (ETL) 和 2,2',7,7'-四[N,N-二(4-甲氧基苯基)氨基]-9,9'- 的应用螺二芴 (spiro-OMeTAD) 作为空穴传输层 (HTL)，会导致器件不稳定。_{TiO 2}的宽带隙特性在 ETL 中引入电荷载流子复合，这反过来又会损害器件性能。除此之外，spiro-OMeTAD 的高成本及其多步合成制备方法也是如此。为了解决上述缺点，已经通过在电荷收集电极和钙钛矿活性层之间引入多功能材料来探索修改界面结构等方法。在这方面，钙钛矿氧化物因其宽带隙和高电子迁移率而更具吸引力。然而，钙钛矿氧化物除了电荷分离效率差、表面亲水性和可见光吸收弱外，还存在团聚性、短路和漏电流等局限性。因此，钙钛矿氧化物与碳基材料，特别是石墨烯及其衍生物的纳米复合材料，由于其优异的光电性能、优异的稳定性和石墨烯基材料的无毒性而引起了广泛的研究关注。因此，这篇综述讨论了石墨烯基材料、它们与钙钛矿氧化物的复合材料、PSC 的有效 ETL 或 HTL 以及光伏性能的后续改进的最新趋势。此外，还总结了钙钛矿氧化物/石墨烯纳米复合材料的合成路线。这篇综述将促进 PSC 制造的进步，提高 PCE 和稳定性。和石墨烯基材料的无毒性。因此，这篇综述讨论了石墨烯基材料、它们与钙钛矿氧化物的复合材料、PSC 的有效 ETL 或 HTL 以及光伏性能的后续改进的最新趋势。此外，还总结了钙钛矿氧化物/石墨烯纳米复合材料的合成路线。这篇综述将促进 PSC 制造的进步，提高 PCE 和稳定性。和石墨烯基材料的无毒性。因此，这篇综述讨论了石墨烯基材料、它们与钙钛矿氧化物的复合材料、PSC 的有效 ETL 或 HTL 以及光伏性能的后续改进的最新趋势。此外，还总结了钙钛矿氧化物/石墨烯纳米复合材料的合成路线。这篇综述将促进 PSC 制造的进步，提高 PCE 和稳定性。