2024, Anomalous phonon behavior and tunable exciton emissions: insights into pressure-driven dynamics in silicon phosphide, Nano Letters.
2024, Anomalous phonon behavior and tunable exciton emissions: insights into pressure-driven dynamics in silicon phosphide, Nano Letters.
Abstract:
IV-V two-dimensional materials have emerged as key contenders for polarization-sensitive and angle-resolved devices, given their inherent anisotropic physical properties. While these materials exhibit intriguing high-pressure quasi-particle behavior and phase transition, the evolution of quasi-particles and their interactions under external pressure remain elusive. Here, employing a diamond anvil cell and spectroscopic measurements coupled with first-principles calculations, we unveil a rarely observed pressure-induced phonon-phonon coupling in layered SiP flakes. This coupling manifests as an anomalous phonon hardening behavior for the A1 mode within a broad wavenumber phonon softening region. Furthermore, we demonstrate the effective tuning of exciton emissions in SiP flakes under pressure, revealing a remarkable 63% enhancement in the degree of polarization (DOP) within the pressure range of 0－3.5 GPa. These findings contribute to our understanding of high-pressure phonon evolution in SiP materials and offer a strategic approach to manipulate the anisotropic performance of in-plane anisotropic 2D materials.
Keywords: Phonon-phonon coupling, Optical characterizations, In-plane anisotropic, Two-dimensional (2D) materials, Diamond anvil cell.
Link: https://pubs.acs.org/doi/full/10.1021/acs.nanolett.4c02250
