Electronic and transport properties of porous graphenes: two-dimensional benzo- and aza-fused π-conjugated-microporous-polymer sheets and boron–nitrogen co-doped derivatives
Inspired by recent successful synthesis of porous frameworks based on aza-fused conjugated-microporous-polymers (Angew. Chem. Int. Ed., 2011, 50, 8753–8757), we investigate electronic and electron transport properties of two-dimensional (2D) benzo-conjugated-microporous-polymer (benzo-CMP) and aza-CMP sheets and their boron-nitrogen (BN) co-doped derivatives using density-functional theory calculations and the non-equilibrium Green's function (NEGF) method. Both benzo-CMP and aza-CMP possess pore diameters about 12 Å and both are semiconductors with a direct bandgap of 0.92 and 1.07 eV, respectively. The BN co-doped derivatives possess smaller bandgaps (0.47 to 0.6 eV). Computed current–voltage (I–Vb) curves are consistent with the semiconducting properties for all 2D systems. The tunable electronic and electron transport properties via BN co-doping offered by benzo-CMP and aza-CMP may be exploited for applications in low-dimensional electronics.