In recent times, perovskite solar cells (PSCs) have been of wide interest in solar energy research, which has ushered in a new era for photovoltaic power sources through the incredible enhancement in their power conversion efficiency (PCE). However, several serious challenges still face their high efficiency: upscaling and commercialization of the fabricated devices, including long-term stability as well as the humid environment conditions of the functional cells. To overcome these obstacles, stable graphene (G) materials with tunable electronic features have been used to assist the crystallization as well as the charge extraction inside the device configuration. Nonetheless, the hole transport layer (HTL)-free PSCs based on graphene materials exhibit unpredictable results, including a high efficiency and long-term stability even in the conditions of an ambient air atmosphere. Herein, we combine graphene materials into a mesoporous TiO₂ electron transfer layer (ETL) to improve the coverage and crystallinity of the perovskite material and minimize charge recombination to augment both the stability and efficiency of the fabricated mixed cation PSCs in ambient air, even in the absence of a HTL. Our results demonstrate that an optimized PSC in the presence of different percentages of graphene materials displays a PCE of up to 17% in the case of a G:TiO₂ ETL doped with 1.5% graphene. With this coverage and crystallinity amendment approach, we show hysteresis-free and stable PSCs, with less decomposition after ∼3000 h of storage under a moist ambient atmosphere. This work focuses on the originalities of the materials, expenses, and the assembling of stable and effective perovskite solar cells.

中文翻译：

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石墨烯辅助结晶和电荷提取用于高效稳定的无空穴传输层钙钛矿太阳能电池

近年来，钙钛矿太阳能电池（PSC）在太阳能研究中引起了广泛的兴趣，通过其功率转换效率（PCE）的惊人提升，它开启了光伏电源的新时代。然而，几个严峻的挑战仍然面临着它们的高效率：制造设备的升级和商业化，包括功能电池的长期稳定性以及潮湿环境条件。为了克服这些障碍，具有可调电子特性的稳定石墨烯 (G) 材料已被用于辅助结晶以及器件配置内的电荷提取。尽管如此，基于石墨烯材料的无空穴传输层（HTL）PSCs表现出不可预测的结果，包括即使在环境空气气氛条件下也具有高效率和长期稳定性。在此，我们将石墨烯材料组合成介孔二氧化钛₂电子转移层 (ETL) 以提高钙钛矿材料的覆盖率和结晶度，并最大限度地减少电荷复合，以提高制造的混合阳离子 PSC 在环境空气中的稳定性和效率，即使在没有 HTL 的情况下也是如此。我们的结果表明，在掺杂 1.5% 石墨烯_{的 G:TiO 2} ETL的情况下，在不同百分比的石墨烯材料存在下优化的 PSC 显示出高达 17% 的 PCE通过这种覆盖率和结晶度修正方法，我们展示了无滞后且稳定的 PSC，在潮湿的环境气氛下储存约 3000 小时后分解较少。这项工作的重点是材料的独创性、费用以及稳定有效的钙钛矿太阳能电池的组装。