Selectively Metallized 2D Materials for Simple Logic Devices.

We herein demonstrate, for the first time, transparent, flexible, and large-area monolithic MoS transistors and logic gates. Each single transistor consists of only two components: a monolithic chemical vapor deposition-grown MoS and an ion gel. Additional electrode materials are not required. The uniqueness of the device configuration is attributed to two factors. One is that a MoS layer is a semiconductor, but it can be doped degenerately; monolithic MoS can thus serve as both the electrodes and the channel of a transistor via selective doping of the material at certain positions. The other is the use of an electrolyte gate dielectric that permits effective gating (<3 V) even from an electrode coplanar with the channel. The resulting monolithic MoS transistors yield excellent device performance, including a maximum mobility of 1.5 cm/V s, an on-off ratio of 10, and a turn-on voltage of -0.69 V. This unique transistor architecture was successfully applied to various semiconductors such as ReS and indium-gallium-zinc oxide. Furthermore, the presented devices exhibit excellent mechanical, operational, and environmental stabilities. Fabrication of complex logic circuits (NOT, NAND, and NOR gates) by integration of the monolithic MoS transistors is demonstrated. Finally, the monolithic MoS transistor was connected to drive red, green, and blue light-emitting diode pixels, which yielded high luminance at a low voltage (<3 V). We believe that the unique architecture of the devices provides a facile way for low-cost, flexible, and high-performance two-dimensional electronics.