Multilayer MoTe₂ Field-Effect Transistor at High Temperatures

Functional 2D material-based devices are likely subjected to high ambient temperatures when integrated into miniaturized circuits for practical applications, which may induce irreversible structural changes in materials and impact the device performance. However, majority of 2D devices' studies focus on room temperature or low-temperature operation conditions. Here, the high-temperature (up to 673 K) electro-thermal response of molybdenum ditelluride (MoTe2) based field-effect transistors is investigated. The optimal annealing temperature of around 500-525 K for the multilayer MoTe2 devices with twofold enhancement in maximum current level, field-effect mobility, and current on-off ratio is identified. Furthermore, MoTe2 devices show the transition of electrical response from gate modulation to the degenerately p-doped (hole dominant) characteristics when the operation temperature increases to approximate to 600 K. The gate-dependent electro-thermal measurements complemented by surface chemistry analysis confirm the near range hopping transport in the MoTe2 channel at high temperature induced by thermally triggered oxidation of MoTe2. These results not only provide the thermal endurance limits of MoTe2 for practical applications, but also indicate the possible applications of MoTe2 for thermal sensing applications.