Engineering phonon thermal transport in few-layer PdSe2

Abstract

Engineering phonon transport in low-dimensional materials has great significance not only for fundamental research, but also for thermal management applications of electric devices. However, due to the difficulties of micro and nano processing and characterization techniques, the work on tuning phonon transport at nanoscale are scarce. In this work, by introducing Ar⁺ plasma, we probed the phonon transport in two-dimensional (2D) layered semiconductor PdSe₂ under different defect concentrations. By using thermal bridge method, the thermal conductivity was measured to decrease by 50% after a certain Ar⁺ irradiation, which implied a possible phase transition. Moreover, Raman characterizations were performed to show that the Raman sensitive peaks of PdSe₂ was red-shifted and finally became disappeared with the increase of defect concentration. “Defect engineering” proves be a practical strategy in tuning the phonon thermal transport in low-dimensional materials, thus providing guidance for potential application in designing thermoelectric devices with various emerging materials.