PtSe₂ Field-Effect Transistors: New Opportunities for Electronic Devices

Abstract

PtSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , a new family of transition metal dichalcogenides, has been explored for electronic device applications using density functional theory and non-equilibrium Green's function within the third nearest neighbor tight-binding approximation. Interestingly, despite its small effective mass (m <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e</sub> * as low as 0.21m <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ; m <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> being electron rest mass), PtSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> has large density of states due to its unique six-valley conduction band within the first Brillouin zone, unlike MoX <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> family. This has direct impacts on the device characteristics of PtSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> field-effect transistors, resulting in superior on-state performance (30% higher on current and transconductance) as compared with the MoSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> counterpart. Our simulation shows that the PtSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> device with a channel longer than 15 nm exhibits near-ideal subthreshold swing, and sub-100 mV/V of drain-induced barrier lowering can be achieved with an aggressively scaled gate oxide, demonstrating new opportunities for electronic devices with novel PtSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> .