氟化硼碳平面的第一性原理研究

基于第一性原理的理论计算,研究了不同氟化程度的BC3,BC5,BC7的稳定结构和电子特征,发现通过B原子替代C原子,F原子与平面结构的结合能力更强了,氟化的硼碳结构比氢化的硼碳结构更加稳定.研究发现:当只有C原子与F原子成键时,体系变成半导体,而当B原子与F原子成键时,即所有原子都与F原子成键,体系变成导体.通过不同程度的氟化,BC3发生半导体-金属的转变,BC5和BC7发生金属-半导体-金属的转变.理论分析表明,B原子的pz轨道对电学性质变化有较大影响.由于其丰富的电学特性,此类氟化硼碳平面在纳米电子器件领域中具有潜在应用,并且该结果对实验合成也有一定的指导意义.

First principles study of fluorinated boron-carbon sheets

Based on the first principles, we investigate the structures and electronic properties of fluorinated BC₃, BC₅, and BC₇. Through the fluorination of BC structure, boron-carbon sheets are more stable than the hydrogenation. The results show that the system becomes semiconductor only on condition that the boron atoms can be bonded with the carbon atoms, whereas, the whole system will become the conductor when all atoms participate in the bonding. With the variation of fluorination degrees, semiconductor-metal transitions appear in the BC₃ compounds and metal-semiconductor-metal transitions appear in the BC₅ and BC₇ sheet. Theoretical analyses find that p_z orbital of boron atoms plays an important role in the electronic transition. Because of the rich electronic properties, this kind of fluorinated boron-carbon compound will become potential nanoelectronic materials and our results can play a role in guiding experiments.
Keywords： first principles boron-carbon compounds electronic properties