Exciton and Carrier Dynamics in 2D Perovskites
arXiv:2006.03843 · doi:10.1021/acs.jpclett.0c02425
Abstract
Two-dimensional Ruddlesden-Popper hybrid lead halide perovskites have become a major topic in perovskite optoelectronics. Here, we aim to unravel the ultrafast dynamics governing the evolution of charge carriers and excitons in these materials. Using a combination of ultrabroadband time-resolved THz (TRTS) and fluorescence upconversion spectroscopies, we find that sequential carrier cooling and exciton formation best explain the observed dynamics, where exciton-exciton interactions play an important role in the form of Auger heating and biexciton formation. We show that the presence of a longer-lived population of carriers is due to these processes and not to a Mott transition. Therefore, excitons still dominate at laser excitation densities. We use kinetic modeling to compare the phenethylammonium and butylammonium organic cations while investigating the stability of the resulting films. In addition, we demonstrate the capability of using ultrabroadband TRTS to study excitons in large binding energy semiconductors through spectral analysis at room temperature.
References in corpus (11)
- Exciton Binding Energy and Nonhydrogenic Rydberg Series in Monolayer WS2
- Phonon coherences reveal the polaronic character of excitons in two-dimensional lead-halide perovskites
- Ultrafast carrier thermalization in lead iodide perovskite probed with two-dimensional electronic spectroscopy
- Real-Time Observation of Exciton-Phonon Coupling Dynamics in Self-Assembled Hybrid Perovskite Quantum Wells
- Stable biexcitons in two-dimensional metal-halide perovskites with strong dynamic lattice disorder
- The effect of Auger heating on intraband carrier relaxation in semiconductor quantumrods
- Accelerated Carrier Relaxation through Reduced Coulomb Screening in 2D Halide Perovskite Nanoplatelets
- Broadband THz study of excitonic resonances in the high-density regime
- Exciton Mott transition in Si Revealed by Terahertz Spectroscopy
- Four-wave mixing in perovskite photovoltaic materials reveals long dephasing times and weaker many-body interactions than GaAs
- Hot Carrier Mobility Dynamics Unravel Competing Sub-ps Cooling Processes in Lead Halide Perovskites