Phase transition in two dimensional materials and their optical applications

The discovery and control of new phases of matter is central for materials research. The emergency of atomically thin 2D materials allows the study of phase transition at 2D limit and benefits the development of new phase transition engineering.  In this talk, we will discuss multiple phase transition mechanisms.  Phase transition can happen interlayer or intralayer in 2D system. Interlayer is governed by covalent bond and intralayer is determined by van der Waals force.  We will cover different engineering approaches to control phase transition in interlayer and intralayer respectively. More interestingly, engineering intralayer interaction becomes one effective approach to control stacking orders, one unique structural degree of freedom in 2D materials.  Then we will show our recent demonstration on optoelectronic devices based on those new discovered phase transition.