Two dimensional (2D) van der Waals (vdW) nanosheet semiconductors have recently attracted much attention from researchers because of their potentials as active device materials toward future nano electronics and - optoelectronics. This review focuses on the performance and applications of stateof-the-art vdW 2D material devices which use transition metal dichalcogenides, graphene, hexagonal boron nitride (h-BN), and black phosphorous: field effect transistors (FETs), complementary metal oxide semiconductor (CMOS) inverters, Schottky diode, and PN diode. High mobility in FETs, electrical switching dynamics in CMOS inverter, photovoltaic switching for dynamic energy harvesting in PN diode, and high current driving FETs for organic light emitting diode pixel switching are demonstrated, however, remaining important issues for future electronics and photonics applications are also introduced. As a final contribution of this review, the ultimate orientations for future applications of 2D devices are forecasted and suggested, which are toward ubiquitous electronics to be a part of internet of things as integrated with existing semiconductor devices. (C) 2016 Elsevier Ltd. All rights reserved.