Press-engineered funnel effect in MoS₂ monolayer homojunction

Abstract

First principles calculations are performed to explore the effect of applied vertical press on the electronic structure of monolayer MoS 2 . It is demonstrated that MoS 2 monolayer exhibits significant modulation of its band gap and band edges by the applied vertical press. Monolayer MoS 2 homojunction with type-I band alignment can be formed by applying vertical press partially on the MoS 2 monolayer. The effect of the vertical press on the electronic structure of MoS 2 monolayer homojunction can be significantly enhanced by enlarging the pressed area. A semiconductor-to-metal transition occurs when the MoS 2 homojunction is subjected to large presses. The varying band diagram including the band edges and band gap leads to a funnelling effect with both holes and electrons concentrate on the pressed region. Our results will provide intriguing opportinuities for designing optoelectronic and photovoltaic devices with good performance based on 2D materials.