Optoelectric Properties of Gate-Tunable MoS₂/WSe₂Heterojunction

Abstract

Two-dimensional transition-metal dichalcogenides semiconductors are attractive materials for optoelectric devices because of their direct energy bandgap and transparency. To investigate the feasibility of transparent p-n junctions, we have fabricated heterojunctions consisting of WSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> since WSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> with proper electrode metals exhibit p-type and n-type behaviors, respectively. These heterojunctions showed rectifying behaviors, indicating that p-n junctions were formed. In addition, photocurrent and photovoltaic effects were observed under light illumination, which were dependent on the gate voltage. Possible origins of gate-tunability are discussed.