近日，中国科学院苏州纳米技术与纳米仿生研究所的马昌期&Ronald Osterbacka及其研究团队取得一项新进展。经过不懈努力，他们研制出功率转换效率超过18%的具有原位衍生SiO_xN_y钝化层的反式结构有机太阳能电池。相关研究成果已于2025年1月9日在国际知名学术期刊《自然—光子学》上发表。

本文提出一种新方法，用于提升反式结构非富勒烯有机太阳能电池的性能和稳定性。该方法采用原位衍生的无机SiO_xN_y钝化层，该层通过在常用ZnO传输层上，于环境大气中固化溶液沉积的全氢聚硅氮烷薄膜而形成。ZnO的氧空穴和悬挂键会在光活性层中形成一个掺杂区域，导致该区域内光生空穴的复合增强，从而造成光电流损失。优化后的SiO_xN_y中间层通过形成Zn–O–Si键，有效钝化了ZnO表面缺陷，消除了掺杂区域。同时，SiO_xN_y促使非富勒烯受体在电子接触附近优先积聚，这也有利于电荷提取。

这两种效应的结合提高了光电流密度和功率转换效率（PCE），使用PM₆:L₈-BO作为光活性层的电池，其认证PCE值分别达到18.49%（有效面积为5.77 mm²）和18.06%（有效面积为100.17 mm²）。重要的是，含有无机SiO_xN_y的电池在白光照射下，预计T80寿命（即PCE降至初始值80%所需的时间）为24,700小时，相当于超过16年的使用寿命。这些结果凸显了该研究方法在高效稳定反式结构有机太阳能电池实际应用中的潜力。原位生长的SiO_xN_y层有助于钝化反式结构有机太阳能电池的表面缺陷，使功率转换效率高达18.49%，预计器件使用寿命超过16年。

据悉，反式结构有机太阳能电池在商业化方面颇具吸引力。然而，其功率转换效率（PCE）仍低于传统结构的有机太阳能电池。

附：英文原文

Title: Inverted organic solar cells with an in situ-derived SiO_xN_y passivation layer and power conversion efficiency exceeding 18%

Author: Liu, Bowen, Sandberg, Oskar J., Qin, Jian, Liu, Yueying, Wilken, Sebastian, Wu, Na, Yu, Xuelai, Fang, Jin, Li, Zhiyun, Huang, Rong, Zha, Wusong, Luo, Qun, Tan, Hongwei, sterbacka, Ronald, Ma, Chang-Qi

Issue&Volume: 2025-01-09

Abstract: Inverted organic solar cells are attractive for commercialization. However, their power conversion efficiency (PCE) still lags their conventional architecture counterpart. Here we propose a new approach to enhance the performance and stability of structure-inverted non-fullerene organic solar cells. We use an in situ-derived inorganic SiO_xN_y passivation layer, formed by curing a solution-deposited perhydropolysilazane thin film in ambient atmosphere on top of the commonly used ZnO transport layer. Oxygen vacancies and dangling bonds of ZnO create a doped region in the photoactive layer, leading to losses in photocurrent due to enhanced recombination of photogenerated holes within this region. The optimized SiOxNy interlayer effectively passivates the ZnO surface defects by forming Zn–O–Si bonds, leading to a vanishing doped region. At the same time, SiO_xN_y induces a preferential accumulation of the non-fullerene acceptor near the electron contact, which also favours charge extraction. The combination of both effects leads to increased photocurrent density and PCE, with certified PCE values of 18.49% and 18.06% for cells with active areas of 5.77 mm² and 100.17 mm², respectively, using PM6:L8-BO as the photoactive layer. Importantly, cells containing inorganic SiOxNy exhibit an estimated T₈₀ lifetime of 24,700 h (where T₈₀ is the time it takes for the PCE to drop to 80% of its initial value) under white light illumination, corresponding to an operational lifespan exceeding 16 years. The results underscore the potential of our approach for practical applications of highly efficient and stable inverted organic solar cells. An in situ-grown layer of SiO_xN_y contributes to passivating surface defects in inverted organic solar cells, enabling power conversion efficiency of up to 18.49% and an estimated device lifespan of over 16 years.

DOI: 10.1038/s41566-024-01574-0

Source: https://www.nature.com/articles/s41566-024-01574-0