Self-trapped excitons in two-dimensional perovskites

• 作 者: Junze LI Haizhen WANG Dehui LI
• 机 构: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 4
• 出 处: 光电子学前沿
• 发表日期: 2020年3期
• 关键词: self-trapped exciton (STE) two-dimensional (2D) perovskites broadband emission e

With strong electron-phonon coupling,the self-trapped excitons are usually formed in materials,which leads to the local lattice distortion and localized excitons.The self-trapping strongly depends on the dimensionality of the materials.In the three-dimensional case,there is a potential barrier for self-trapping,whereas no such barrier is present for quasi-one-dimensional systems.Two-dimensional (2D) systems are marginal cases with a much lower potential barrier or nonexistent potential barrier for the self-trapping,leading to the easier formation of self-trapped states.Self-trapped excitons emission exhibits a broadband emission with a large Stokes shift below the bandgap.2D perovskites are a class of layered structure material with unique optical properties and would find potential promising optoelectronic.In particular,self-trapped excitons are present in 2D perovskites and can significantly influence the optical and electrical properties of 2D perovskites due to the soft characteristic and strong electron-phonon interaction.Here,we summarized the luminescence characteristics,origins,and characterizations of self-trapped excitons in 2D perovskites and finally gave an introduction to their applications in optoelectronics.