Synthetic two-dimensional (2D) materials provide an opportunity to realize large-scale applications in next generation electronic and optoelectronic devices. One of the biggest challenges of synthetic 2D materials is the lateral heterogeneity such as non-uniform strain, composition and defect density. The electronic and optical properties are found to be not uniform in many cases, even within a single crystalline domain, potentially limiting synthetic 2D materials in advanced devices. In this work, we probe the origin of the widely observed lateral heterogeneities in synthetic monolayer MoS 2 . Epitaxial single crystalline domains (~10 µ m) are optically homogeneous and uniform with 0.3%–0.4% tensile strain, while misoriented domains (>20 µ m) exhibit distinct photoluminescence (PL) emissions from the center to the edge, along with released strain at the center. Temperature-dependent Raman and PL mapping reveals that the center of non-epitaxial domains ex…
Published in: "2DMaterials".