Li Shuyu, Li Chaoran, Liu Chu, Wu Jiachen, Siqin Letu, Li Yuan, Cui Guonan, Yang Yanchun, Liu Ruijian, Luan Hongmei, Zhu Chengjun
Inner Mongolia Key Laboratory of Semiconductor Photovoltaic Technology and Energy Materials, Center for Quantum Physics and Technologie, School of Physical Science and Technology, Inner Mongolia University, Hohhot, Inner Mongolia, 010021, China.
School of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot, Inner Mongolia, 010022, China.
Adv Sci (Weinh). 2025 Aug;12(30):e04087. doi: 10.1002/advs.202504087. Epub 2025 May 23.
This work unveils a diffusion-kinetic modulation strategy that fundamentally redefines sodium management in kesterite photovoltaics, enabling spatially controlled Na sequestration within CuZnSn(S,Se) (CZTSSe) absorber layers through a thermally engineered "Na-locking" mechanism. By establishing critical correlations between post-processing thermal protocols and alkali metal migration dynamics, how synchronized extension of sintering duration and rapid cooling termination creates a non-equilibrium state that traps Na at strategic interfacial positions is demonstrated. This approach leverages Na's dual functionality as a crystallization promoter and defect passivator, driving concurrent improvements in crystallographic coherence and electronic uniformity. The optimized absorber architecture features laterally expanded grains with reduced boundary density and homogenized interfacial charge transport pathways, yielding the highest reported efficiency of 13.22% for Na-doped CZTSSe solar cells to date, marked by synergistic enhancements in both V and FF. Crucially, this substrate-derived Na regulation paradigm outperforms conventional extrinsic doping methods through its self-limiting diffusion characteristics, ensuring compositional stability while eliminating secondary phase risks. The methodology establishes a universal framework for defect engineering in chalcogenide photovoltaics, bridging fundamental insights into alkali metal diffusion thermodynamics with scalable manufacturing solutions. These findings advance kesterite solar cell technology and offer a blueprint for optimizing thin-film devices, improving process tolerance and material sustainability.
这项工作揭示了一种扩散动力学调制策略，该策略从根本上重新定义了锡基硫属化合物光伏中的钠管理，通过热工程“钠锁定”机制，在CuZnSn(S,Se)（CZTSSe）吸收层内实现空间可控的钠螯合。通过建立后处理热协议与碱金属迁移动力学之间的关键关联，证明了烧结持续时间的同步延长和快速冷却终止如何创造一种非平衡状态，将钠捕获在关键的界面位置。这种方法利用了钠作为结晶促进剂和缺陷钝化剂的双重功能，推动了晶体相干性和电子均匀性的同时提高。优化后的吸收体结构具有横向扩展的晶粒，边界密度降低，界面电荷传输路径均匀化，使钠掺杂的CZTSSe太阳能电池迄今报告的最高效率达到13.22%，其特征是开路电压（V）和填充因子（FF）均有协同提高。至关重要的是，这种源自衬底的钠调控模式通过其自限性扩散特性优于传统的非本征掺杂方法，确保了成分稳定性，同时消除了次生相风险。该方法为硫属化合物光伏中的缺陷工程建立了一个通用框架，将对碱金属扩散热力学的基本认识与可扩展的制造解决方案联系起来。这些发现推动了锡基硫属化合物太阳能电池技术的发展，并为优化薄膜器件、提高工艺耐受性和材料可持续性提供了蓝图。
