Six novel carbon and silicon allotropes with their potential application in photovoltaic field
Wei Zhang, Changchun Chai, Qingyang Fan, Yanxing Song, Yintang Yang
Abstract
Abstract By stacking up five novel cagelike structures, three novel three-dimensional (3D) sp 3 bonding networks, named h P24, h P30 and h P36, were predicted in this work for the first time. These three newly discovered structures have trigonal unit cell with the space groups of P −3 m 1, P −3 m 1 and P 3 m 1, respectively. Using first-principle calculations, the physical properties, including structural, mechanical, electronic and optical properties of C and Si in h P24, h P30 and h P36 phases were systematically studied. All these newly discovered carbon and silicon allotropes were proven to be thermodynamically and mechanically stable. The wide indirect bandgap value in range of 3.89–4.03 eV suggests that C in h P24, h P30 and h P36 phases have the potential to be applied in high frequency and high power electronic devices. The direct bandgap value in range of 0.60–1.16 eV, the smaller electron and hole effective mass than diamond-Si, and the significantly better photon absorption characteristics than diamond-Si suggest that h P24-Si, h P30-Si and h P36-Si are likely to have better performance in photovoltaic applications than diamond-Si. h P24-Si also has the potential to be applied in infrared detectors.