C‐chain‐doping induced band‐state transition in armchair AlN nanoribbons (Phys. Status Solidi B 8/2016)

Among monolayer materials, graphite‐like hexagonal (h‐)AlN nanosheets show a high potential for device applications. AlN nanoribbons (AlNNRs), i.e., quasi‐1D monolayer h‐AlN, have been the subject of theoretical research. However, the corresponding band states in AlNNRs are still unclear. Tong et al. (pp. 1643–1648 ) study the effect of doping on the band states of AlNNRs by comparing the h‐AlN nanosheet, perfect aAlNNRs, and single C‐chain‐doped aAlNNRs. For aAlNNRs with a width N < 12, the nonedge C‐chain doping can lead to a transfer of conduction‐band minimum (CBM) electrons from the central part of the ribbon to the C–N–Al ring. As a representative model, aAlNNRs with a width of 8 ([aAlNNR] 8 ) were mainly studied. In contrast to a h‐AlN monolayer, the authors find a second degenerate state (above the Fermi level) in perfect [aAlNNR] 8 , which stems from Al‐s p y and hybridized N‐s p z orbitals. However, both degenerate states are suppressed by single C‐chain doping. For N ≥ 12, wherever a C‐chain locates, the CBM always displays similarly delocalized characteristics. The study shows that single C‐chain doping can significantly modify the band states, an observation that might be interesting for the investigation of other III–V nanoribbons, too.