Fig. 1From: The Role of Air Adsorption in Inverted Ultrathin Black Phosphorus Field-Effect Transistors a Optical image and SEM image of the inverted FET. b Fabrication process of the device. ① The first EBL patterning obtain the Cr/Au electrode (15/60 nm), the channel of each electrode is 2 μm. ② Transfer of the ultrathin BP. ③ Transfer of the h-BN. ④ The second EBL patterning obtain the Ti/Au electrode (20/60 nm). c The AFM integrated data, BP thickness of 6 nm on the top of 24 nm h-BNBack to article page