飞秒激光加载下二维氮化硼损伤机理研究

Study on the Mechanism of Femtosecond Laser Induced Damage to Two Dimensional Hexagonal Boron Nitride

二维氮化硼用在纳米电子及光电子领域时,常用飞秒脉冲激光进行加工,因此研究飞秒激光与二维六角氮化硼(h_BN)相互作用具有很好的应用价值。本文基于含时密度泛函理论研究了飞秒激光脉冲与二维h_BN纳米片相互作用,研究结果表明:激光脉冲作用在二维h_BN纳米片时,N-H键、B-H键键长被拉长,B-N键逐渐被破坏,最终导致二维h_BN整个结构坍塌而解体。此外,还发现激光强度影响N-H、B-H、B-N键最先断裂时间;同时飞秒激光的极化方向影响电荷密度分布。

As two dimensional hexagonal boron nitrides （ h_BN） are applied in the fields of nano-electric and nano-optielectric, they are microprocessed by femtosecond （ fs） pulsed laser and it is valuable to investigate the interplays of fs laser with h_BN. Mechanism of interactions between fs laser and h_BN nanosheet based on time dependent density functional theory was studied. It is found that B-H, N-H, B- N bond lengths are elongated as laser interacts h_BN and B-N bonds are gradually broken. Subsequently, structures of h_BN are damaged. Furthermore, it is also shown that the laser strength influences damage time when the bonds are firstly broken. Meanwhile, the distribution of charge densities which depends on laser polarization also catches variation.