Hot Polarons with Trapped Excitons and Octahedra-Twist Phonons in CH3NH3PbBr3 Hybrid Perovskite Nanowires

Abstract

Hybrid Perovskites have shown a great potential for applications in photovoltaics and light-emitting devices with high efficiency. Interaction between defect-induced trapped excitons and phonons plays an important role in understanding the emerging phenomena for such an excellent figure-of-merit. Here we demonstrate hot polarons with narrow linewidth in $\mathrm{C}{\mathrm{H}}_3\mathrm{N}{\mathrm{H}}_3\mathrm{PbB}{\mathrm{r}}_3$ nanowires, which originate from the interaction between trapped excitons and octahedra-twist phonons. The observation of hot polarons in photoluminescence without gain methods indicates the large interaction strength between excitons and phonons. The multiple hot polarons are further confirmed by magneto-optical spectra with a Zeeman splitting of the trapped excitons and a phonon energy increase with diamagnetic effect. Furthermore, the phonons participating in the interaction are demonstrated to be the octahedra-twist vibrations which are transverse optical phonons, while the interaction between trapped excitons and longitudinal optical phonons is weak. Our work demonstrates that trapped excitons in perovskites prefer to interact with transverse rather than longitudinal optical phonons. Since bulk materials usually interact with longitudinal optical phonons, this result provides a physical explanation of the high tolerance of defects in perovskites.

16 pages, 4 figures

References in corpus (5)

• Giant Rydberg Excitons in Cuprous Oxide
• Optical Phonons in Methylammonium Lead Halide Perovskites and Implications for Charge Transport
• Slow cooling of hot polarons in halide perovskite solar cells
• Enhanced Strong Interaction between Nanocavities and p-shell Excitons Beyond the Dipole Approximation
• Many-Body Effect of Mesoscopic Localized States in MoS${}_2$ Monolayer

Cited by in corpus (3)

• Strong Triplet-Exciton-LO-Phonon Coupling in Two-Dimensional Layered Organic-Inorganic Hybrid Perovskite Single Crystal Microflakes
• Coupling of MoS${}_2$ Excitons with Lattice Phonons and Cavity Vibrational Phonons in Hybrid Nanobeam Cavities
• Terahertz Kerr effect in a methylammonium lead bromide perovskite crystal