Patterning of type-II Dirac semimetal PtTe2 for optimized interface of tellurene optoelectronic device

Abstract

The controllable transformation between the semiconductor and metal plays a key role for the electronic and optoelectronic applications of atomically thin two-dimensional (2D) layered materials. Herein, we report laserdriven synthesis of PtTe2 from Pt-deposited 2D tellurium (Te) for optimized interface of 2D Te optoelectronic device. The size and shape of the synthesized area of the PtTe2 can be designable in the laser irradiation process. The electrical properties of 2D Te change from p-type semiconducting to metallic due to the formation of semimetallic PtTe2 after laser irradiation, increasing the conductivity by factors of 500. In addition, by using PtTe2 contact, the carrier mobility and photoresponsivity of the 2D Te devices could be greatly enhanced. Our photodetector shows high responsivity and detectivity up to 5.8 x 104 A W-1 and 5.31 x 1011 Jones, respectively. Ideal interfaces for highly performing optoelectronics devices could be realized by an original way of depositing Pt nanoparticles and patterning a semimetal compound based on the Pt at the junction.