[7a-C16-1~12] 17.2 Graphene

[7a-C16-3] Ultra-heavy doping of graphene with a layered electride support: probing a divergent van Hove singularity

〇Takeshi Inoshita^1,2, Masaru Tsukada³, Susumu Saito¹, Hideo Hosono¹ (1.Tokyo Tech, 2.NIMS, 3.Tohoku Univ.)

Keywords:nanocarbon, low-dimensional material, electride

Layered electrides are novel quasi-two-dimensional low-work-function metals with sheets of electrons (anionic electrons) accumulated between the ionic layers. Recently, we have found that these materials also have electron accumulation outside their surfaces to maintain charge neutrality. In this talk, we report our DFT electronic structure calculation for graphene deposited on a Ca₂N support. With the deposition of graphene, the extra-surface anionic electrons of Ca₂N disappear completely and are transferred to graphene. Graphene is doped to a record high density of n=5x10¹⁴ cm^-2 and the Fermi level reaches the logarithmically-divergent van Hove singularity of graphene's pi* band for which various quantum instabilities have been predicted to occur.