摘要
近年来,钙钛矿作为一种新型的能源材料受到了众多学者的广泛关注。由于其具有较高的吸收系数、载流子迁移率以及扩散长度而被应用到光电器件中,例如:太阳能电池、光电探测器、场效晶体管以及发光二极管等。器件界面电荷转移过程则是影响钙钛矿材料性能的一个关键因素,在本工作中,利用表面增强拉曼光谱,研究了钙钛矿材料的电荷转移性质;制备了MAPbCl3钙钛矿单晶以及多晶薄膜,并在其表面沉积一层酞菁铜分子;随后,在酞菁铜表面再次沉积一层银膜。试图通过表面增强拉曼光谱(SERS)技术研究钙钛矿-钛菁铜界面的电荷转移过程以及表面银膜所产生的表面等离子体共振对于界面电荷转移及SERS性质的影响。研究结果表明,钙钛矿材料与钛菁铜分子能级匹配,且对于532 nm激发波长的激光具有良好的响应;532 nm激光能够诱导界面电荷转移过程的发生。同时,表面沉积的银膜可以进一步放大SERS信号。这主要是由于银膜的表面等离子体共振能够增强电荷分离,提高电荷转移效率,同时其表面产生的较强的电磁场,可以进一步增强钛菁铜分子的Raman信号强度。
The charge transfer(CT)process plays a key role in the operation of the optoelectronic device system so a better understanding of the interfacial CT property is greatly important.In this paper,Surface Enhanced Raman Scattering(SERS)was utilized to study the interfacial CT property between CuPc and perovskites(single crystal and polycrystalline).The Raman spectra of CuPc adsorbed on the perovskite surface was enhanced.The laser wavelength dependent SERS study indicates that this phenomenon is mainly arising from the CT from the VB band of perovskite to the LUMO band of the CuPc molecules.In comparison,the SERS signal of CuPc molecules adsorbed on a single crystal is much stronger than that on the polycrystalline perovskite.This result indicates that the defect status affects the enhancement ability of the materials.Further study shows that,after the decoration of a thin silver film,the SERS spectra of CuPc on both single crystal and polycrystalline perovskites are further enhanced.The extreme enhancement is not only due to the electromagnetic property of the silver film but also the fact that the SPR of the silver enhances the charge separation of the perovskite,which further promotes the CT process between the substrate and adsorbed molecules.The CT based SERS study shows great potential application value in the field of optoelectronic research.
作者
于治
于伟利
郭春雷
YU Zhi;YU Wei-li;GUO Chun-lei(The Guo China-US Photonics Laboratory,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun130033,China;The Institute of Optics,University of Rochester,Rochester,NY14627,USA)
出处
《中国光学》
EI
CAS
CSCD
北大核心
2019年第5期952-963,共12页
Chinese Optics
基金
Supported by National Key R&D Program of China(No.2017YFB1104700)
National Natural Science Foundation(No.61705227,No.61774155,No.11774340)
Jilin Provincial Science&Technology Development Project(No.20180414019GH)
Scientific Research Project of the Chinese Academy of Sciences(No.QYZDB-SSWSYS038)
The Key Program of the International Partnership Program of CAS(No.181722KYSB20160015)~~
