Phan Thi Thu Trinh, Nguyen Thi Thuy Kieu, Mac Trung Kien, Trinh Minh Tuan
Chemistry and Biochemistry Department, Utah State University, 300 Old Main Hill, Logan, UT 84322, USA.
Physics Department, Utah State University, 300 Old Main Hill, Logan, UT 84322, USA.
Nanomaterials (Basel). 2025 Jun 1;15(11):847. doi: 10.3390/nano15110847.
Metal halide perovskite (MHP) nanocrystals (NCs) offer great potential for high-efficiency optoelectronic devices; however, they suffer from structural softness and chemical instability. Doping MHP NCs can overcome this issue. In this work, we synthesize Mn-doped methylammonium lead bromide (MAPbBr) NCs using the ligand-assisted reprecipitation method and investigate their structural and optical stability. X-ray diffraction confirms Mn⁺ substitution at Pb⁺ sites and lattice contraction. Photoluminescence (PL) measurements show a blue shift, significant PL quantum yield enhancement, reaching 72% at 17% Mn⁺ doping, and a 34% increase compared to undoped samples, attributed to effective defect passivation and reduced non-radiative recombination, supported by time-resolved PL data. Mn⁺ doping also improves long-term stability under ambient conditions. Low-temperature PL reveals the crystal-phase transitions of perovskite NCs and Mn-doped NCs to be somewhat different than those of pure MAPbBr. Mn⁺ incorporation into perovskite promotes self-assembly into superlattices with larger crystal sizes, better structural order, and stronger inter-NC coupling. These results demonstrate that Mn⁺ doping enhances both optical performance and structural robustness, advancing the potential of MAPbBr NCs for stable optoelectronic applications.
金属卤化物钙钛矿（MHP）纳米晶体（NCs）在高效光电器件方面具有巨大潜力；然而，它们存在结构柔软性和化学不稳定性问题。掺杂MHP NCs可以克服这一问题。在这项工作中，我们使用配体辅助再沉淀法合成了锰掺杂的甲基溴化铅铵（MAPbBr）NCs，并研究了它们的结构和光学稳定性。X射线衍射证实了Mn⁺在Pb⁺位点的取代和晶格收缩。光致发光（PL）测量显示出蓝移、显著的PL量子产率提高，在17%的Mn⁺掺杂时达到72%，与未掺杂样品相比增加了34%，这归因于有效的缺陷钝化和减少的非辐射复合，时间分辨PL数据支持了这一点。Mn⁺掺杂还提高了在环境条件下的长期稳定性。低温PL揭示了钙钛矿NCs和锰掺杂NCs的晶相转变与纯MAPbBr的晶相转变有所不同。Mn⁺掺入钙钛矿促进了自组装成具有更大晶体尺寸、更好结构有序性和更强NC间耦合的超晶格。这些结果表明，Mn⁺掺杂提高了光学性能和结构稳健性，推动了MAPbBr NCs在稳定光电器件应用中的潜力。
