Achievement

Since the isolation of graphene, a single layer of carbon atoms, in 2005, research into two-dimensional materials has progressed rapidly. While graphene, as a truly two-dimensional material, possesses many unique properties, its metallic nature limits optoelectronic applications. Its semiconducting cousin, a single layer of molybdenum disulfide (MoS2), is a promising material for creating atomically-thin, highly-flexible optoelectronic devices. Moreover, the atomic structure of MoS2 gives rise to a "valley" index for its charge carriers, in addition to the usual charge and spin indices, which is sensitive to the polarization state of incident light. IGERT Fellow Kathryn McGill and her collaborators have fabricated single-layer MoS2 transistors and begun studying their optoelectronic properties. In addition to observing a photovoltaic response in monolayer MoS2, they have studied the material’s electronic response to polarized light and are searching for a valley Hall effect.