RbPb_(2)Cl_(5)的合成及光学性质  

Synthesis and Optical Properties of RbPb_(2)Cl_(5)

作　　者：张志男 程海明 滕士勇[2] 张颖[1] ZHANG Zhinan;CHENG Haiming;TENG Shiyong;ZHANG Ying(College of Chemistry,Jilin University,Changchun 130012,China;First Hospital,Jilin University,Changchun 130021,China)

机构地区：[1]吉林大学化学学院,长春130012 [2]吉林大学第一医院,长春130021

出　　处：《高等学校化学学报》2022年第11期35-41,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:51872114)资助。

摘　　要：采用机械研磨的方法,通过控制反应前驱体的摩尔比,研究了不同球磨时间对形成RbPb_(2)Cl_(5)晶体的影响.X射线衍射结果表明,经过1 h的研磨可制备纯相RbPb_(2)Cl_(5)晶体粉末,其结构为通过边共享相连接的[Pb-Cl_(7)]十面体,归属于单斜晶系P2_(1)/c空间点群.RbPb_(2)Cl_(5)晶体在紫外区有明显的吸收,其带边吸收值为3.82 eV.在光激发条件下,该晶体显示激发波长依赖的540 nm黄绿光和635 nm橙光的双波长荧光.变温光谱、时间分辨光谱和发射峰强度与能量密度依赖的线性关系研究表明,其发光机制应该归结于材料具有两种不同的自陷激子态,从而产生了与激发波长相关的双通道发射.Lead-based perovskites have been extensively studied due to their excellent optoelectronic properties Compared to the typical CsPbX_(3) material,the study of RbPb_(2)X_(5) perovskites material is relatively backward.In this paper,the effect of different ball milling times on the formation of RbPb_(2)Cl_(5) crystals was investigated b controlling the molar ratio of reaction precursors using a mechanical grinding method.The X-ray diffraction resul showed that the pure phase RbPb_(2)Cl_(5) crystal powder could be prepared after 1 h of grinding,and its structure wa attributed to the monoclinic crystal system with[Pb-Cl_(7)]decahedra connected by edge-sharing phases,and th P2_(1)/C space point group.The RbPb_(2)Cl_(5) crystals show significant absorption in the UV region with a band edg absorption value of 3.82 eV.Under photoexcitation conditions,the crystals display excitation wavelength dependen dual wavelength fluorescence of yellow-green light at 540 nm and orange light at 635 nm.The study of the variabl temperature spectra,time-resolved spectra and the linear dependence of the intensity of the emission peaks on the energy density suggests that the luminescence mechanism should be attributed to the fact that the material ha two different self-trapped excitonic states,resulting in a dual-channel emission dependent on the excitation wavelength.

关 键 词：三维RbPb_(2)Cl_(5) 机械研磨合成 激发波长相关发射 

分 类 号：O614[理学—无机化学]