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Photocurrent Switching of Monolayer MoS2 Using a Metal-Insulator Transition
Jin Hee Lee1,2, Hamza Zad Gul1,2, Hyun Kim1,2
1Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
Abstract:
We achieve switching on/off the photocurrent of monolayer molybdenum disulfide (MoS2) by controlling the metal-insulator transition (MIT). N-type semiconducting MoS2 under a large negative gate bias generates a photocurrent attributed to the increase of excess carriers in the conduction band by optical excitation. However, under a large positive gate bias, a phase shift from semiconducting to metallic MoS2 is caused, and the photocurrent by excess carriers in the conduction band induced by the laser disappears due to enhanced electron-electron scattering. Thus, no photocurrent is detected in metallic MoS2. Our results indicate that the photocurrent of MoS2 can be switched on/off by appropriately controlling the MIT transition by means of gate bias.
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