Giant exciton Mott density in anatase TiO2
arXiv:2007.10051 · doi:10.1103/PhysRevLett.125.116403
Abstract
Elucidating the carrier density at which strongly bound excitons dissociate into a plasma of uncorrelated electron-hole pairs is a central topic in the many-body physics of semiconductors. However, there is a lack of information on the high-density response of excitons absorbing in the near-to-mid ultraviolet, due to the absence of suitable experimental probes in this elusive spectral range. Here, we present a unique combination of many-body perturbation theory and state-of-the-art ultrafast broadband ultraviolet spectroscopy to unveil the interplay between the ultraviolet-absorbing two-dimensional excitons of anatase TiO and a sea of electron-hole pairs. We discover that the critical density for the exciton Mott transition in this material is the highest ever reported in semiconductors. These results deepen our knowledge of the exciton Mott transition and pave the route toward the investigation of the exciton phase diagram in a variety of wide-gap insulators.
References in corpus (16)
- BerkeleyGW: A Massively Parallel Computer Package for the Calculation of the Quasiparticle and Optical Properties of Materials and Nanostructures
- Effect of spin-orbit interaction on the excitonic effects in single-layer, double-layer, and bulk MoS2
- Photo-Induced Bandgap Renormalization Governs the Ultrafast Response of Single-Layer MoS2
- Strongly bound excitons in anatase TiO2 single crystals and nanoparticles
- Ultrafast screening and carrier dynamics in ZnO: Theory and experiment
- Exciton Mott transition in Si Revealed by Terahertz Spectroscopy
- Rydberg excitons in the presence of an ultralow-density electron-hole plasma
- Hubbard exciton revealed by time-domain optical spectroscopy
- Interplay of the exciton and electron-hole plasma recombination on the photoluminescence dynamics in bulk GaAs
- Predicting the Ionization Threshold for Carriers in Excited Semiconductors
- Exciton Mott transition revisited
- Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO2 Nanoparticles
- Electron-Phonon-Driven Three-Dimensional Metallicity in an Insulating Cuprate
- Role of Quantum-Confinement in Anatase Nanosheets
- Emerging giant resonant exciton induced by Ta-substitution in anatase TiO: a tunable correlation effect
- Anomalous Anisotropic Exciton Temperature Dependence in Rutile TiO2