Reducing Band Gap and Enhancing Carrier Mobility of Boron Nitride Nanoribbons by Conjugated π Edge States

The wide band gap of boron nitride (BN) materials has been a main bottleneck for their wide applications in electronics. In this work, by means of density functional theory (DFT) computations, we demonstrated that the band gaps of BN nanoribbons (BNNRs), with either zigzag or armchair edges, can be significantly reduced by C 2 H termination. The neighboring C 2 H terminal groups of BNNRs can covalently connect with each other, forming infinite carbon chains along the edges. The newly formed carbon chains introduce conjugated π edge states, which contribute to the band gap reduction of BNNRs. C 2 H termination can also result in higher carrier mobility for BNNRs. This simple strategy offers great opportunities for developing BNNR-based electronic devices.