Reversible Transition of Semiconducting PtSe<sub>2</sub> and Metallic PtTe<sub>2</sub> for Scalable All-2D Edge-Contacted FETs
Sang Sub Han, Shahid Sattar, Dmitry Kireev, June‐Chul Shin, Tae‐Sung Bae, Hyeon Ih Ryu, Justin Cao, Alex Ka Shum, Jung Han Kim, C. M. Canali, Deji Akinwande, Gwan‐Hyoung Lee, Hee‐Suk Chung, Yeonwoong Jung
Abstract
Two-dimensional (2D) transition metal dichalcogenide (TMD) layers are highly promising as field-effect transistor (FET) channels in the atomic-scale limit. However, accomplishing this superiority in scaled-up FETs remains challenging due to their van der Waals (vdW) bonding nature with respect to conventional metal electrodes. Herein, we report a scalable approach to fabricate centimeter-scale all-2D FET arrays of platinum diselenide (PtSe 2 ) with in-plane platinum ditelluride (PtTe 2 ) edge contacts, mitigating the aforementioned challenges. We realized a reversible transition between semiconducting PtSe 2 and metallic PtTe 2 via a low-temperature anion exchange reaction compatible with the back-end-of-line (BEOL) processes. All-2D PtSe 2 FETs seamlessly edge-contacted with transited metallic PtTe 2 exhibited significant performance improvements compared to those with surface-contacted gold electrodes, e.g., an increase of carrier mobility and on/off ratio by over an order of magnitude, achieving a maximum hole mobility of ∼50.30 cm 2 V –1 s –1 at room temperature. This study opens up new opportunities toward atomically thin 2D-TMD-based circuitries with extraordinary functionalities.