"Mid-infrared Optoelectronics and Electronics in Black Phosphorus and Graphene"
Black phosphorus (BP) and graphene are promising candidates for mid-infrared optoelectronics due to their strong light-matter interaction properties and narrow or vanishing bandgap. In this talk, I will first present the efficient bandgap tuning in thin-film black phosphorus. Through transport study, we show that the bandgap can be continuously tuned from 300 to below 100 meV by a moderate vertical displacement field of ~1.1 V/nm. Based on this concept, we further developed tunable mid-infrared BP photodetectors and light emitting devices. I will also present our recent observation of colossal mid-infrared photoresponse in twisted bilayer graphene (TBG), leveraging the superlattice-induced bandgaps and large density of states (DOS). By performing low temperature transport measurements, we reveal that the nature of the photoresponse is due to the bolometric effect.
Bingchen Deng is currently a Ph.D. Student at Professor Fengnian Xia's research group in Department of Electrical Engineering at Yale University.