Abstract:
In this presentation, high-quality single crystals of numerous layer chalcogenides compounds were successfully grown by chemical vapor transport, liquid phase and various crystal-growth techniques. Owing to the reduced lower dimension of the 2D layered structure, a lot of excitonic features and many body effects can be clearly observed and detected in those novel chalcogenides compounds. Over the past thirty years, our laboratory utilized modulation spectroscopy, especially thermoreflectance TR, and the other optical techniques like PL, TRPL and micro-optical techniques for characterization of the excitonic features and band-edge transitions in the novel 2D layered semiconductors. The excitonic transitions that related to light emission, optical absorption and optoelectronics applications (including in-plane anisotropy) will be demonstrated and discussed herein.