Controlled Charge Polarity in WSe2 Field‐Effect Transistor Grown by Self‐Flux Method

In 2D materials, tungsten diselenide (WSe 2 ) has great potential for optical and electronic devices. However, the quality of WSe 2 crystals, determined by defects and grain boundaries, currently restricts its performance in controlling carrier‐transport properties. Consequently, the most significant issue achieves superior growth of WSe 2 crystals and appropriate metal contacts. Herein, a doping‐free approach to manipulate the polarity of WSe 2 transistors by utilizing distinct metal contacts is presented. WSe 2 field‐effect transistors are examined employing low‐ and high‐work function metals. In these findings, a transition in polarity from n‐type for In and Cr to p‐type for Pd and Au is demonstrated, showcasing remarkably high on/off ratios (≈10 7 ) and mobilities (≈117 cm 2 V −1 s −1 ) at room temperature. This straightforward polarity control technique can be further extended by utilizing contact architecture‐based research in other 2D materials for future nano‐electrical and optoelectronic devices.