<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 MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> field-effect transistors (FETs) with graphene/Ti as the heterocontacts have been fabricated, showing more than 160-mA/mm drain current at 1-μm gate length with an ON-OFF current ratio of 107. 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 MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> FETs without graphene contact layer. Temperature-dependent study on MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /graphene heterocontacts has been also performed, still unveiling its Schottky contact nature. Transfer length method and a devised I-V method have been introduced to study the contact resistance and Schottky barrier height in MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /graphene/metal heterocontacts structure.