Performance Improvement of MoS2-Based MOSFETs With Graphene Quantum Dots Pretreatment Technology

Molybdenum disulfide (MoS2 has attracted tremendous interest in the generation electronics and optoelectronics field due to its unique electrical and optical properties. However, the electrical contact between MoS2 and metal is one of the urgent challenges for restricting the performance of MoS2 field effect transistors (FETs). Herein, we demonstrate contact engineering using graphene quantum dots (GQDs) for improving the device’s performance. The materials characteristic indicates the existence of charge transfer between GQDs and MoS2. As a result, the contact resistance (49.7
$\text{k}\Omega \cdot \mu \text{m}^{-{1}}{)}$
and effective Schottky barrier height (103 meV) reduce to 2.4
$\text{k}\Omega \cdot \mu \text{m}^{-{1}}$
and 41 meV, respectively. The improved MoS2 FET offers
${I}_{\text {ON}}/{I}_{\text {OFF}}$
ratio over
$10^{{7}}$
, field-effect mobility of ~55.8 cm2/
$\text{V}\cdot \text{s}$
, and
${I}_{\text {ON}}$
current density of ~80
$\mu \text{A}/\mu \text{m}$
exceeding 320% than pristine MoS2 FET. Further, the effect of optimized contact on the photoelectric performance of MoS2 FET is studied, and the observations are explained qualitatively based on an equivalent circuit of the transistor. This work provides a simple and promising route for the exploration of high-performance 2-D-based semiconductor devices.