Ghorai Arup, Das Avijit, Choi Yoonsun, Roy Baidyanath, Jeong Unyong
Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea.
School of Nano Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.
Small. 2024 Nov;20(45):e2404384. doi: 10.1002/smll.202404384. Epub 2024 Jul 19.
Among the lead halide perovskite (LHP) family, CsPbI is known to be significantly vulnerable to moisture, which hinders its use in real device applications. It is reported that chalcogen-based ligands can better stabilize CsPbI and revive nanocrystals (NCs). Here, diphenyl diselenide (DPhDSe) ligand is used to revive the degraded CsPbI NCs through a post-synthetic treatment of adding a small amount of DPhDSe in the degraded NC dispersion. DPhDSe in the dispersion formed nanofibrillar crystals at a low temperature through the π-π stacking of the phenyl ring. The nanofibrils played as a template on which the NCs self-assembled and they are attached side-by-side to form microfibers. The microfiber powder containing the NCs is optically stable at ambient conditions and morphologically self-healable by mild thermal annealing due to the dynamic Se─Se bond. The mechanism of the structural changes, optical transitions, and chemical changes has been systematically characterized through electron microscopy, diffraction, spectroscopy, and elemental analysis.
在卤化铅钙钛矿（LHP）家族中，已知CsPbI极易受潮，这阻碍了其在实际器件应用中的使用。据报道，基于硫族元素的配体可以更好地稳定CsPbI并使纳米晶体（NCs）恢复活性。在此，通过在降解的NC分散体中添加少量二苯基二硒醚（DPhDSe）进行合成后处理，使用二苯基二硒醚（DPhDSe）配体来恢复降解的CsPbI NCs的活性。分散体中的DPhDSe通过苯环的π-π堆积在低温下形成纳米纤维状晶体。纳米纤维起到模板的作用，NCs在其上自组装，并并排附着形成微纤维。含有NCs的微纤维粉末在环境条件下光学稳定，并且由于动态的Se─Se键，通过温和的热退火在形态上可自我修复。通过电子显微镜、衍射、光谱学和元素分析系统地表征了结构变化、光学跃迁和化学变化的机制。
