Selective oxidation of the surface layer of bilayer WSe2 by laser heating

Abstract

WSe2 films have several anisotropies between the in-plane and out-of-plane directions, which affects their responses to external operation. Guided by the anisotropies, we provide adequate heat propagation to oxidize selectively the surface layer of bilayer WSe2 and characterized the structure of monolayer WSe2 covered with an oxidized layer by optical and atomic force microscopy, Raman spectroscopy and photoluminescence measurements. Furthermore, we found indications that laser treatments of monolayer WSe2 covered with an oxidized layer have possibility to cause photoactivated oxidation. Our observations suggest clues to understand low-dimensional oxidation behaviours.