Exciton–phonon coupling in two-dimensional materials: from phenomena to applications

Exciton–phonon coupling is a fundamental interaction governing the optical, electronic, and thermal properties of semiconductors. Two-dimensional (2D) materials, with reduced dielectric screening and strong confinement, exhibit enhanced exciton binding energies and exciton–phonon coupling, offering a rich platform for studying related phenomena. Here, we provide a brief review of exciton–phonon interactions in 2D materials. We first introduce the basic physical mechanisms, including the Huang–Rhys factor and different coupling regimes. Then, we summarize representative phenomena such as phonon-assisted upconversion, self-trapped excitons, exciton formation dynamics, and phonon-mediated dark-exciton processes. Next, we discuss exciton–spin–phonon coupling in van der Waals magnetic materials. Finally, we highlight emerging applications, including solid-state laser cooling, single-photon sources, and exciton-optomechanics, and provide perspectives on future research directions in this field.