Reversible tuning of charge Carrier's polarity of MoTe2 FETs enabled by laser and high temperature

The transition metal dichalcogenides (TMDs) materials exhibit variety of crystal phase structures and vulnerable to extrinsic doping for phase transformation, leading diverse electronic applications. Here we demonstrate the controlled charge carrier's polarity in the phase transition of molybdenum ditelluride (MoTe2) based field effect transistors (FETs) affected by laser irradiations in ambient environment. The conductivity in MoTe2-based FETs was measured before and after laser irradiations in a range of temperatures (77, 100, 150, 200, 250, 300, 350 and 400 K). The devices achieved reversible charge polarity by changing its 2H phase to semimetal 1Tʹ phase upon laser irradiations and returned to its original state once treated with high temperature 400 K. Since, the 1Tʹ phase is confirmed by Raman spectroscopy, transmission electron microscopy (TEM) and electrical transport measurements. Thus, our finding provides an effective approach in controlling charge carrier's modulation in laser-doped 2D materials for electronic and optoelectronic applications.