Near-field visualization of charge transfer at MoSe2/WSe2 lateral heterojunction

Abstract

Lateral heterojunction (HJ) of two-dimensional transition metal dichalcogenides has various optoelectronic applications that utilize in-plane charge separation. However, it has been difficult to identify charge transfer characteristics at HJ due to the limited spatial resolution of optical spectroscopy. In this study, near-field scanning optical microscopy is used to directly image the exciton separation occurring at the lateral MoSe2/WSe2 HJ, which was found to be similar to 370 nm in spatial width. Efficient charge separation at HJ was confirmed by inspecting local variations of trion and exciton emissions of MoSe2 and WSe2. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen