Ultrafast Laser Spectroscopy of Two-Dimensional Materials Beyond Graphene

Starting with the discovery of graphene in 2004, the interest in two-dimensional materials since then has been exponentially growing. Across many disciplines, their exceptional electrical, chemical, thermal, and optical properties have drawn considerable attention that has created an entire field within a decade of their discovery. Driven by the mechanical exfoliation technique that allows for the quick exploration of these two-dimensional materials and their novel devices, joint efforts have been made in order to understand and exploit their potential, consequently leading to the development of their large-scale growth. This review focuses on recent studies using ultrafast laser spectroscopy that have revealed the photocarrier dynamics in two-dimensional materials and laid the foundation of their behavior. We provide a brief introduction on ultrafast laser spectroscopy, discuss several aspects of the photocarrier dynamics, and conclude with our perspective on future developments.