Li Jiayi, Wang Yang, Saha Santanu, Chen Zhihengyu, Hofmann Jan, Misleh Jason, Chapman Karena W, Reimer Jeffrey A, Filip Marina R, Karunadasa Hemamala I
Department of Chemistry, Stanford University, Stanford, California, 94305, United States.
Department of Chemical and Biomolecular Engineering, College of Chemistry, UC Berkeley, Berkeley, California, 94720, United States.
Angew Chem Int Ed Engl. 2024 Oct 7;63(41):e202408443. doi: 10.1002/anie.202408443. Epub 2024 Sep 5.
We incorporate Se into the 3D halide perovskite framework using the zwitterionic ligand: SeCYS (NH(CH)Se), which occupies both the X and A sites in the prototypical ABX perovskite. The new organoselenide-halide perovskites: (SeCYS)PbX (X=Cl, Br) expand upon the recently discovered organosulfide-halide perovskites. Single-crystal X-ray diffraction and pair distribution function analysis reveal the average structures of the organoselenide-halide perovskites, whereas the local lead coordination environments and their distributions were probed through solid-state Se and Pb NMR, complemented by theoretical simulations. Density functional theory calculations illustrate that the band structures of (SeCYS)PbX largely resemble those of their S analogs, with similar band dispersion patterns, yet with a considerable band gap decrease. Optical absorbance measurements indeed show band gaps of 2.07 and 1.86 eV for (SeCYS)PbX with X=Cl and Br, respectively. We further demonstrate routes to alloying the halides (Cl, Br) and chalcogenides (S, Se) continuously tuning the band gap from 1.86 to 2.31 eV-straddling the ideal range for tandem solar cells or visible-light photocatalysis. The comprehensive description of the average and local structures, and how they can fine-tune the band gap and potential trap states, respectively, establishes the foundation for understanding this new perovskite family, which combines solid-state and organo-main-group chemistry.
SeCYS（NH(CH)Se）将硒掺入三维卤化物钙钛矿框架中，该配体占据了典型ABX钙钛矿中的X和A位点。新型有机硒化物-卤化物钙钛矿：(SeCYS)PbX（X = Cl、Br）在最近发现的有机硫化物-卤化物钙钛矿的基础上进行了拓展。单晶X射线衍射和对分布函数分析揭示了有机硒化物-卤化物钙钛矿的平均结构，而通过固态硒和铅核磁共振探测了局部铅配位环境及其分布，并辅以理论模拟。密度泛函理论计算表明，(SeCYS)PbX的能带结构在很大程度上类似于其硫类似物，具有相似的能带色散模式，但带隙有相当大的减小。光吸收测量确实表明，对于X = Cl和Br的(SeCYS)PbX，其带隙分别为2.07和1.86 eV。我们进一步展示了卤化物（Cl、Br）和硫族化物（S、Se）合金化的途径，可将带隙连续调节至1.86至2.31 eV，跨越串联太阳能电池或可见光光催化的理想范围。对平均结构和局部结构的全面描述，以及它们如何分别微调带隙和潜在陷阱态，为理解这个结合了固态化学和有机主族化学的新型钙钛矿家族奠定了基础。
