Out-of-plane optical absorption, emission and carrier dynamics in layered materials

Abstract Layered materials have garnered significant interest for their unique optical properties and potential in optoelectronic applications. These materials exhibit strong light–matter interactions due to their anisotropic crystal structures, which can be modulated in both in-plane and out-of-plane directions. The discovery of materials like black phosphorus have furthered research into anisotropic layered materials, offering new opportunities for polarization-sensitive devices and photodetectors. This review focuses on recent advances in out-of-plane optical properties of layered materials, with an emphasis on their absorption and emission characteristics. The interplay in monoelemental, binary two-dimensional materials and two-dimensional heterostructures is also explored, providing insights into their potential for novel applications in photonics and optoelectronics. Challenges and future prospects are also discussed.