Synthesis of Atomically Thin Hexagonal Diamond with Compression
Feng Ke, Lingkong Zhang, Yabin Chen, Ketao Yin, Chenxu Wang, Yan‐Kai Tzeng, Yu Lin, Hongliang Dong, Zhenxian Liu, John S. Tse, Wendy L. Mao, Junqiao Wu, Bin Chen
Abstract
Atomically thin diamond, also called diamane, is a two-dimensional carbon allotrope and has attracted considerable scientific interest because of its potential physical properties. However, the successful synthesis of a pristine diamane has up until now not been achieved. We demonstrate the realization of a pristine diamane through diamondization of mechanically exfoliated few-layer graphene via compression. Resistance, optical absorption, and X-ray diffraction measurements 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 ∼1.0 GPa. Theoretical calculations indicate that a (-2110)-oriented h-diamane is energetically stable and has a lower enthalpy than its few-layer graphene precursor above the transition pressure. Compared to gapless graphene, semiconducting h-diamane offers exciting possibilities for carbon-based electronic devices.