▎ 摘　　要

We developed means to produce wafer scale, high-quality graphene films as large as 3 in. wafer size on NI and Cu films under ambient pressure and transfer them onto arbitrary substrates through instantaneous etching of metal layers. we also demonstrated the applications of the large-area graphene films for the batch fabrication of held-effect transistor (FET) arrays and stretchable strain gauges showing extraordinary performances. Transistors showed the hole and electron mobilities of the device of 1100 +/- 70 and 550 +/- 50 cm(2)/(V s) at drain bias of -0.75 V, respectively. The piezo-resistance gauge factor of strain sensor was similar to 6.1. These methods represent a significant. step toward the realization of graphene devices in wafer scale as well as application in optoelectronics, flexible and stretchable electronics.