C. S. Chang ChienH. M. ChangW. T. LeeM. R. TangCHAO-HSIN WUSI-CHEN LEE2019-10-242019-10-24201721583226https://scholars.lib.ntu.edu.tw/handle/123456789/428055https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028607129&doi=10.1063%2f1.4996136&partnerID=40&md5=0212259a1b75fd0bb9ead0b43ac2732eAn ohmic contact of graphene/MoS2 heterostructure is determined by using ultraviolet photoelectron spectroscopy (UPS). Since graphene shows a great potential to replace metal contact, a direct comparison of Cr/Au contact and graphene contact on the MoS2 thin film transistor (TFT) is made. Different from metal contacts, the work function of graphene can be modulated. As a result, the subthreshold swing can be improved. And when Vg<VFB, the intrinsic graphene changes into p-type, so graphene contact can achieve lower off current by lowering the Fermi level. To further improve the performance of MoS2 TFT, a new method using graphene contact first and MoS2 layer last process that can avoid PMMA residue and high processing temperature is applied. MoS2 TFT using this method shows on/off current ratio up to 6×106 order of magnitude, high mobility of 116 cm2/V-sec, and subthreshold swing of only 0.515 V/dec. © 2017 Author(s).[SDGs]SDG7Field effect transistors; Graphene; Ohmic contacts; Processing; Thin film transistors; Ultraviolet photoelectron spectroscopy; Graphene contacts; High mobility; High processing temperatures; Metal contacts; Off current; ON/OFF current ratio; P-type; Subthreshold swing; Graphene transistorsjournal article10.1063/1.49961362-s2.0-85028607129