Integrated wafer-scale ultra-flat graphene by gradient surface energy modulation
Xin Gao, Liming Zheng, Fang Luo, Jun Qian, Jingyue Wang, Mingzhi Yan, Wendong Wang, Qinci Wu, Junchuan Tang, Yisen Cao, Congwei Tan, Jilin Tang, Mengjian Zhu, Yani Wang, Yanglizhi Li, Luzhao Sun, Guanghui Gao, Jianbo Yin, Li Lin, Zhongfan Liu, Shiqiao Qin, Hailin Peng
Abstract
Abstract The integration of large-scale two-dimensional (2D) materials onto semiconductor wafers is highly desirable for advanced electronic devices, but challenges such as transfer-related crack, contamination, wrinkle and doping remain. Here, we developed a generic method by gradient surface energy modulation, leading to a reliable adhesion and release of graphene onto target wafers. The as-obtained wafer-scale graphene exhibited a damage-free, clean, and ultra-flat surface with negligible doping, resulting in uniform sheet resistance with only ~6% deviation. The as-transferred graphene on SiO 2 /Si exhibited high carrier mobility reaching up ~10,000 cm 2 V −1 s −1 , with quantum Hall effect (QHE) observed at room temperature. Fractional quantum Hall effect (FQHE) appeared at 1.7 K after encapsulation by h-BN, yielding ultra-high mobility of ~280,000 cm 2 V −1 s −1 . Integrated wafer-scale graphene thermal emitters exhibited significant broadband emission in near-infrared (NIR) spectrum. Overall, the proposed methodology is promising for future integration of wafer-scale 2D materials in advanced electronics and optoelectronics.