Homogeneous 2D MoTe 2 p–n Junctions and CMOS Inverters formed by Atomic‐Layer‐Deposition‐Induced Doping

Recently, α‐MoTe 2 , a 2D transition‐metal dichalcogenide (TMD), has shown outstanding properties, aiming at future electronic devices. Such TMD structures without surface dangling bonds make the 2D α‐MoTe 2 a more favorable candidate than conventional 3D Si on the scale of a few nanometers. The bandgap of thin α‐MoTe 2 appears close to that of Si and is quite smaller than those of other typical TMD semiconductors. Even though there have been a few attempts to control the charge‐carrier polarity of MoTe 2 , functional devices such as p–n junction or complementary metal–oxide–semiconductor (CMOS) inverters have not been reported. Here, we demonstrate a 2D CMOS inverter and p–n junction diode in a single α‐MoTe 2 nanosheet by a straightforward selective doping technique. In a single α‐MoTe 2 flake, an initially p‐doped channel is selectively converted to an n‐doped region with high electron mobility of 18 cm 2 V −1 s −1 by atomic‐layer‐deposition‐induced H‐doping. The ultrathin CMOS inverter exhibits a high DC voltage gain of 29, an AC gain of 18 at 1 kHz, and a low static power consumption of a few nanowatts. The results show a great potential of α‐MoTe 2 for future electronic devices based on 2D semiconducting materials.