Photocurrent Switching of Monolayer MoS$_{\mathrm{2}}$ using Metal-Insulator Transition

We achieve photocurrent switching of monolayer molybdenum disulfide (MoS$_{\mathrm{2}})$ by controlling the metal--insulator transition (MIT). N-type semiconducting MoS$_{\mathrm{2}}$ that is under a large negative gate bias, generates photocurrent by an optical excitation that is attributed to the increase of excess carriers in the conduction band. However, under a large positive gate bias that causes a phase shift from the semiconducting to a metallic MoS$_{\mathrm{2}}$ the photocurrent by excess carriers in the conduction band by the laser disappears by enhanced electron--electron scattering. Thus, no photocurrent is detected in metallic MoS$_{\mathrm{2}}$ Our results indicate that the photocurrent of MoS$_{\mathrm{2}}$ can be switched by MIT transition that is controllable using the gate bias.