Field‐Effect Thermoelectric Hotspot in Monolayer Graphene Transistor

Abstract

AbstractGraphene is a promising candidate for the thermal management of downscaled microelectronic devices owing to its exceptional electrical and thermal properties. Nevertheless, a comprehensive understanding of the intricate electrical and thermal interconversions at a nanoscale, particularly in field‐effect transistors with prevalent gate operations, remains elusive. In this study, nanothermometric imaging is used to examine a current‐carrying monolayer graphene channel sandwiched between hexagonal boron nitride dielectrics. It is revealed for the first time that beyond the expected Joule heating, the thermoelectric Peltier effect actively plays a significant role in generating hotspots beneath the gated region. With gate‐controlled charge redistribution and a shift in the Dirac point position, an unprecedented systematic evolution of thermoelectric hotspots, underscoring their remarkable tenability is demonstrated. This study reveals the field‐effect Peltier contribution in a single graphene‐material channel of transistors, offering valuable insights into field‐effect thermoelectrics and future on‐chip energy management.