<inline-formula> <tex-math notation="TeX">${\rm MoS}_{2}$ </tex-math></inline-formula> Field-Effect Transistors With Graphene/Metal Heterocontacts

Abstract

For the first time, n-type few-layer <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">${\rm MoS}_{2}$ </tex-math></inline-formula> field-effect transistors (FETs) with graphene/Ti as the heterocontacts have been fabricated, showing more than 160-mA/mm drain current at 1- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$\mu{\rm m}$ </tex-math></inline-formula> gate length with an ON-OFF current ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$10^{7}$ </tex-math></inline-formula> . The enhanced electrical characteristic is confirmed in a nearly 2.1 times improvement in ON-resistance and a 3.3 times improvement in contact resistance with heterocontacts compared with the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">${\rm MoS}_{2}$ </tex-math></inline-formula> FETs without graphene contact layer. Temperature-dependent study on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">${\rm MoS}_{2}/{\rm graphene}$ </tex-math></inline-formula> heterocontacts has been also performed, still unveiling its Schottky contact nature. Transfer length method and a devised <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$I{-}V$ </tex-math></inline-formula> method have been introduced to study the contact resistance and Schottky barrier height in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">${\rm MoS}_{2}/{\rm graphene}/{\rm metal}$ </tex-math></inline-formula> heterocontacts structure.