Specifically, we found that AA stacking, in which atoms in the top layer directly overlap atoms in the bottom layer, and AB stacking, in which atoms in the top layer do not directly overlap atoms in the bottom layer, resulted in a threefold enhancement of the former in the nonlinear optical response of the SHG. (nanowerk.com)
Class1
Janus Transition Metal Dichalcogenides (TMDs) are a specific class of 2D materials , typically composed of a transition metal (such as molybdenum or tungsten) sandwiched between two chalcogen elements (such as sulfur, selenium, or tellurium). (nanowerk.com)