Degenerate p-Type and n-Type Doping of Diamane by Molecular Adsorption

Abstract

Motivated by the successful synthesis of two-dimensional diamane [Nat. Nanotechnol. 2020, 15, 59-66], in this work, the electronic and optical properties of diamane with molecular adsorption are investigated by first-principles calculation. Based on the surface transfer doping mechanism, we report the degenerate p-type and n-type doping for hydrogenated diamane (H-diamane) and fluorinated diamane (F-diamane), respectively. Hole accumulation on H-diamane and degenerate levels in the density of states (DOS) are found when organic molecules (tetracyanoethylene, tetracyanoquinodimethane, and tetrafluorotetracyanoquinodimethane) and transition-metal oxides (MoO 3 , CrO 3 , WO 3 , V 2 O 5 , and ReO 3 ) are chosen as acceptors on H-diamane. Conversely, F-diamane shows electron accumulation and degenerate levels in DOS when organic molecules (decamethylcobaltocene and cobaltocene 2 ) are adsorbed. The carrier concentration values of H-diamane and F-diamane are 1.91 × 10 13 to 3.96 × 10 13 cm −2 and 1.96 × 10 13 to 3.38 × 10 13 cm −2 , respectively. After adsorption, the optical absorption increases significantly in the visible-light region. Our findings would provide a feasible route to modulate the electronic and optical properties of diamane.