Indirect Bandgap Puddles in Monolayer MoS₂ by Substrate‐Induced Local Strain

Abstract

An unusually large bandgap modulation of 1.23-2.65 eV in monolayer MoS₂ on a SiO₂ /Si substrate is found due to the inherent local bending strain induced by the surface roughness of the substrate, reaching the direct-to-indirect bandgap transition. Approximately 80% of the surface area reveals an indirect bandgap, which is confirmed further by the degraded photoluminescence compared to that from suspended MoS₂ .