Synthesis of Diamane with Compression
일 시 : 2020년 11월 27일 금요일 10:30
연 사 : Bin Chen
소 속 : Center for High Pressure Science & Technology Advanced Research, China
장 소 : 온라인 진행 ( https://us02web.zoom.us/j/84281887278 , 줌회의 ID: 842 8188 7278 )
초 록
Atomically thin diamond (called diamane, one allotrope of graphene) has attracted considerable scientific interest because of its predicted physical and mechanical properties. However, the successful synthesis of a free-standing, pristine diamane has up until now been elusive. Here, we demonstrate the realization of such diamane films through the diamondization of mechanically exfoliated few-layer graphene via compression. Resistance, optical absorption, and x-ray diffraction measurements, along with theoretical calculations reveal that hexagonal diamane (h-diamane) with a bandgap of 2.8±0.3 eV forms by compressing trilayer and thicker graphene to above 20 GPa at room temperature and can be preserved upon decompression to a few GPa. Raman and TEM studies indicate that the fewlayer graphene sample after high pressure and thermal treatment also has the h-diamane structure, i.e., h-diamane can be recovered back to ambient conditions. Compared to gapless graphene, diamane with sizable bandgap offers exciting possibilities for carbon-based electronic devices.