Song Tao, Wang Cheng-Qiang, Lu Haolin, Mu Xi-Jiao, Wang Bo-Long, Liu Ji-Zhong, Ma Bo, Cao Jing, Sheng Chuan-Xiang, Long Guankui, Wang Qiang, Zhang Hao-Li
Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Key Laboratory of Special Function Materials and Structure Design, Ministry of Education, Lanzhou University, Lanzhou, 730000, China.
Key Laboratory of Photovoltaic Science and Technology, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai, 200433, China.
Angew Chem Int Ed Engl. 2024 May 21;63(21):e202400769. doi: 10.1002/anie.202400769. Epub 2024 Apr 22.
Generating circularly polarized luminescence (CPL) with simultaneous high photoluminescence quantum yield (PLQY) and dissymmetry factor (g) is difficult due to usually unmatched electric transition dipole moment (μ) and magnetic transition dipole moment (m) of materials. Herein we tackle this issue by playing a "cascade cationic insertion" trick to achieve strong CPL (with PLQY of ~100 %) in lead-free metal halides with high g values reaching -2.3×10 without using any chiral inducers. Achiral solvents of hydrochloric acid (HCl) and N, N-dimethylformamide (DMF) infiltrate the crystal lattice via asymmetric hydrogen bonding, distorting the perovskite structure to induce the "intrinsic" chirality. Surprisingly, additional insertion of Cs cation to substitute partial (CH)NH transforms the chiral space group to achiral but the crystal maintains chiroptical activity. Further doping of Sb stimulates strong photoluminescence as a result of self-trapped excitons (STEs) formation without disturbing the crystal framework. The chiral perovskites of indium-antimony chlorides embedded on LEDs chips demonstrate promising potential as CPL emitters. Our work presents rare cases of chiroptical activity of highly luminescent perovskites from only achiral building blocks via spontaneous resolution as a result of symmetry breaking.
由于材料的电偶极矩（μ）和磁偶极矩（m）通常不匹配，要同时实现高光致发光量子产率（PLQY）和不对称因子（g）来产生圆偏振发光（CPL）是很困难的。在此，我们通过运用“级联阳离子插入”技巧来解决这个问题，在不使用任何手性诱导剂的情况下，在无铅金属卤化物中实现了强CPL（PLQY约为100%），g值高达-2.3×10 。盐酸（HCl）和N，N-二甲基甲酰胺（DMF）等非手性溶剂通过不对称氢键渗透到晶格中，使钙钛矿结构发生扭曲，从而诱导出“内在”手性。令人惊讶的是，额外插入Cs阳离子以取代部分（CH）NH 会使手性空间群转变为非手性，但晶体仍保持手性光学活性。进一步掺杂Sb会由于自陷激子（STE）的形成而激发强光致发光，同时不会干扰晶体框架。嵌入在LED芯片上的铟 - 锑氯化物手性钙钛矿显示出作为CPL发射器的潜在应用前景。我们的工作展示了仅通过非手性结构单元，由于对称性破缺而自发拆分产生的高发光钙钛矿的手性光学活性的罕见案例。
