▎ 摘　　要

The ultraclean transfer of graphene grown by chemical vapor deposition is vital for applications in thinfilm electronic and optoelectronic devices such as photodetectors. In this study, a methyl methacrylate (MMA)-enabled ultraclean graphene transfer method is demonstrated. First-principles calculations based on density functional theory were conducted to study the interaction between MMA and graphene. The calculation results show extremely low adsorption energy (E-ad. = 0.84 eV) for MMA molecules on graphene. Besides, the weak atomic hybridization between MMA and graphene makes the ultraclean graphene transfer possible. The transferred graphene has a low roughness with a Root Mean Square of 0.96 nm. The ultraclean graphene was used in the fabrication of fast response graphene/GaN ultraviolet photodetectors with a rising time and decaying time of 0.5 and 1.12 ms, respectively. The MMA transferred graphene could open a feasible pathway to develop large-area ultraviolet photodetectors with fast response. (C) 2020 Elsevier Ltd. All rights reserved.