近日，我集团周海特聘教授团队在无铅钙钛矿纳米线器件领域取得新进展，以“Defect Passivation on LeadFree CsSnI₃ Perovskite Nanowires Enables HighPerformance Photodetectors with UltraHigh Stability”为题，发表于SCI期刊Nano-Micro Letters，太阳集团www0638为第一通信单位。《Nano-Micro Letters》属于中科院一区TOP期刊，影响因子23.655。

近年来，无铅CsSnI₃钙钛矿材料以其优异的光电性能和低毒性在光电器件中备受关注。然而，CsSnI₃中的深能级缺陷，如高密度的锡空位、SnI^6-八面体的结构变形和Sn²⁺态的氧化，是实现具有良好稳定性的高性能CsSnI₃基光电器件的主要挑战。课题组采用缺陷钝化方法来解决上述问题。通过将1-丁基-2,3-二甲基咪唑氯化盐（BMIMCl）掺入钙钛矿中来制备超稳定和高性能的CsSnI₃纳米线（NW）光电探测器（PD）。通过材料分析和理论计算，BMIM+离子可以有效钝化Sn相关缺陷并降低CsSnI₃ NW PD的暗电流。为了进一步降低器件的暗电流，引入了聚甲基丙烯酸甲酯，最终双钝化CsSnI₃ NWPD显示出超高性能，具有2×10^-11 A的超低暗电流、高达0.237 A/W的响应率、1.18×10¹²琼斯的高探测度和180 dB的线性动态范围。此外，未封装的器件在空气中（25℃，50%湿度）储存60天后，器件性能保持在90%以上，表现出超高的稳定性。

周海特聘教授是我校2021年引进的学科方向领军人才。其团队长期致力于低维半导体材料的微纳结构及光电器件性能研究。2022年以来，课题组成员在一维钙钛矿纳米线、Ga₂O₃纳米线等领域取得一系列重要进展，相关成果以第一/通信作者单位发表于InfoMat、Chemical Engineering Journal、Advanced Optical Materials、Photonics Research等高水平国际期刊10篇。该工作是课题组在前面工作的基础上取得的又一突破，论文第一作者为太阳集团www0638、武汉大学和湖北大学联合培养的硕士研究生高正，合作者武汉大学方国家教授和赵江博士为共同通讯作者。本研究得到了国家自然科学基金（51972101, 62074117, 12134010）和深圳基础研究计划（JCYJ20190808152609307）等资助。

引文信息：

Defect Passivation on LeadFree CsSnI₃ Perovskite Nanowires Enables HighPerformance Photodetectors with UltraHigh Stability

Zheng Gao, Hai Zhou,* Kailian Dong, Chen Wang, Jiayun Wei, Zhe Li, Jiashuai Li, Yongjie Liu, Jiang Zhao*, Guojia Fang*

Nano-Micro Lett. 14, 215(2022). https://doi.org/10.1007/s40820-022-00964-9

撰稿、一审：周海 二审：张睿 三审：任斌

Professor Hai Zhou's Team Publishes Research in Nano-Micro Letters

Date: November 30, 2022
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Recently, Professor Hai Zhou’s research team at the International School of Microelectronics, Dongguan University of Technology has made new progress in the field of lead-free perovskite nanowire devices. Their study, titled "Defect Passivation on Lead-Free CsSnI₃ Perovskite Nanowires Enables High-Performance Photodetectors with Ultra-High Stability," has been published in the SCI journal Nano-Micro Letters, with Dongguan University of Technology as the first corresponding institution. Nano-Micro Letters is a top-tier Chinese Academy of Sciences (CAS) Q1 journal with an impact factor of 23.655.

In recent years, lead-free CsSnI₃ perovskite materials have attracted significant attention in optoelectronic devices due to their excellent optoelectronic properties and low toxicity. However, deep-level defects in CsSnI₃, such as high-density tin vacancies, structural deformation of SnI₆⁴⁻ octahedra, and oxidation of Sn²⁺, pose major challenges in achieving high-performance CsSnI₃-based optoelectronic devices with good stability. The research team addressed these issues using a defect passivation strategy. By incorporating 1-butyl-2,3-dimethylimidazolium chloride (BMIMCl) into the perovskite material, they successfully fabricated ultra-stable and high-performance CsSnI₃ nanowire (NW) photodetectors (PDs).

Through material analysis and theoretical calculations, the study demonstrated that BMIM⁺ ions effectively passivate Sn-related defects and reduce the dark current of CsSnI₃ NW PDs. To further suppress the dark current, poly(methyl methacrylate) (PMMA) was introduced. The final dual-passivated CsSnI₃ NW PDs exhibited outstanding performance, including an ultra-low dark current of 2 × 10⁻¹¹ A, a high responsivity of 0.237 A/W, an impressive detectivity of 1.18 × 10¹² Jones, and a linear dynamic range (LDR) of 180 dB. Additionally, even after being stored in ambient air (25°C, 50% humidity) for 60 days without encapsulation, the device retained over 90% of its initial performance, demonstrating exceptional stability.

Professor Hai Zhou was recruited in 2021 as a leading talent in disciplinary development at our university. His team has long been dedicated to the research of micro- and nano-structured low-dimensional semiconductor materials and their optoelectronic properties. Since 2022, the research team has achieved a series of significant advancements in the field of one-dimensional perovskite nanowires and Ga₂O₃ nanowires. Their work has resulted in 10 high-impact journal publications in top-tier international journals, including InfoMat, Chemical Engineering Journal, Advanced Optical Materials, and Photonics Research, as first/corresponding authorship affiliations. This latest study represents another breakthrough built upon their previous work.

The first author of this paper, Zheng Gao, is a master's student jointly trained by the Dongguan University of Technology, Wuhan University, and Hubei University. Professors Guojia Fang and Dr. Jiang Zhao from Wuhan University are the co-corresponding authors. This research was supported by the National Natural Science Foundation of China (51972101, 62074117, 12134010) and the Shenzhen Basic Research Program (JCYJ20190808152609307).

Citation:
"Defect Passivation on Lead-Free CsSnI₃ Perovskite Nanowires Enables High-Performance Photodetectors with Ultra-High Stability"
Authors: Zheng Gao, Hai Zhou, Kailian Dong, Chen Wang, Jiayun Wei, Zhe Li, Jiashuai Li, Yongjie Liu, Jiang Zhao, Guojia Fang
Journal: Nano-Micro Letters, 14, 215 (2022).
DOI: 10.1007/s40820-022-00964-9

Drafted & First Review: Hai Zhou
Second Review: Rui Zhang
Final Review: Bin Ren