近日，北京大学的朱瑞及其研究小组与英国牛津大学的Henry J. Snaith以及云南大学的吕正红等人合作并取得一项新进展。经过不懈努力，他们成功研制出用于钙钛矿太阳能电池的多功能氧化镱缓冲层。相关研究成果已于2024年1月17日在国际权威学术期刊《自然》上发表。

该研究团队报道了一种化学稳定的多功能缓冲材料，氧化镱(YbO_x)，用于可扩展热蒸发沉积的p-i-n 钙钛矿太阳能电池。研究人员将该YbO_x缓冲层用于具有窄带隙钙钛矿吸收体的p-i-n 钙钛矿太阳能电池中，获得了超过25%的认证功率转换效率。研究人员还证明了YbO_x在从各种类型的钙钛矿吸收层中实现高效钙钛矿太阳能电池方面的广泛适用性，宽带隙钙钛矿吸收层和中带隙钙钛矿吸收层的效率分别为20.1%和22.1%。此外，当受到ISOS-L-3加速老化时，YbO_x封装的器件表现出明显增强的器件稳定性。

据悉，钙钛矿太阳能电池（PSCs）由夹在几层不同的电荷选择性材料之间的固体钙钛矿吸收体组成，确保了器件的单向电流流动和高压输出。在p型/固有/n型（p-i-n）PSCs（也称为反式PSCs）中，电子选择层和金属电极之间的“缓冲材料”使电子从电子选择层流向电极，并作为一个屏障，抑制有害物质进入钙钛矿吸收体或降解产物的相互扩散。目前，可蒸发的有机分子和原子层沉积的金属氧化物已被成功应用，但它们都存在一定的缺陷。

附：英文原文

Title: Multifunctional ytterbium oxide buffer for perovskite solar cells

Author: Chen, Peng, Xiao, Yun, Hu, Juntao, Li, Shunde, Luo, Deying, Su, Rui, Caprioglio, Pietro, Kaienburg, Pascal, Jia, Xiaohan, Chen, Nan, Wu, Jingjing, Sui, Yanping, Tang, Pengyi, Yan, Haoming, Huang, Tianyu, Yu, Maotao, Li, Qiuyang, Zhao, Lichen, Hou, Cheng-Hung, You, Yun-Wen, Shyue, Jing-Jong, Wang, Dengke, Li, Xiaojun, Zhao, Qing, Gong, Qihuang, Lu, Zheng-Hong, Snaith, Henry J., Zhu, Rui

Issue&Volume: 2024-01-17

Abstract: Perovskite solar cells (PSCs) comprise a solid perovskite absorber sandwiched between several layers of different charge-selective materials, ensuring unidirectional current flow and high voltage output of the devices. A ‘buffer material’ between the electron-selective layer and the metal electrode in p-type/intrinsic/n-type (p-i-n) PSCs (also known as inverted PSCs) enables electrons to flow from the electron-selective layer to the electrode. Furthermore, it acts as a barrier inhibiting the inter-diffusion of harmful species into or degradation products out of the perovskite absorber. Thus far, evaporable organic molecules and atomic-layer-deposited metal oxides have been successful, but each has specific imperfections. Here we report a chemically stable and multifunctional buffer material, ytterbium oxide (YbO_x), for p-i-n PSCs by scalable thermal evaporation deposition. We used this YbO_x buffer in the p-i-n PSCs with a narrow-bandgap perovskite absorber, yielding a certified power conversion efficiency of more than 25%. We also demonstrate the broad applicability of YbO_x in enabling highly efficient PSCs from various types of perovskite absorber layer, delivering state-of-the-art efficiencies of 20.1% for the wide-bandgap perovskite absorber and 22.1% for the mid-bandgap perovskite absorber, respectively. Moreover, when subjected to ISOS-L-3 accelerated ageing, encapsulated devices with YbO_x exhibit markedly enhanced device stability.

DOI: 10.1038/s41586-023-06892-x

Source: https://www.nature.com/articles/s41586-023-06892-x