CAJ | 학술논문

采用密度泛函理论(DFT)方法系统研究了表面吸附碱金属 Li原子的超短碳纳米管([8]cyclophe-nacene)体系的结构和非线性光学性质.在这些体系中， Li原子均能稳定地吸附在超短碳纳米管表面，其吸附能高达84.0~106.2 kJ/mol.当吸附1~2个Li原子时， Li原子和碳纳米管之间发生了明显的电荷转移过程，使体系的一阶超极化率(β0)值明显改善，β0值从0迅速增加到3.42×103~8.29×103 a. u.；当吸附的Li原子数增加到3时，体系内部产生了额外电子，有效地降低了体系最主要跃迁的跃迁能，使体系的一阶超极化率进一步提升(高达2.59×106a. u.).此外， Li原子之间的距离也是影响吸附体系β0值的重要因素.
채용밀도범함이론(DFT)방법계통연구료표면흡부감금속 Li원자적초단탄납미관([8]cyclophe-nacene)체계적결구화비선성광학성질.재저사체계중， Li원자균능은정지흡부재초단탄납미관표면，기흡부능고체84.0~106.2 kJ/mol.당흡부1~2개Li원자시， Li원자화탄납미관지간발생료명현적전하전이과정，사체계적일계초겁화솔(β0)치명현개선，β0치종0신속증가도3.42×103~8.29×103 a. u.；당흡부적Li원자수증가도3시，체계내부산생료액외전자，유효지강저료체계최주요약천적약천능，사체계적일계초겁화솔진일보제승(고체2.59×106a. u.).차외， Li원자지간적거리야시영향흡부체계β0치적중요인소.
Under the density functional theory(DFT) method, the structures and nonlinear optical(NLO) properties of seven new Lin@cyclophenacene ( n=1-3 ) species were investigated in detail, where one to three Li atoms are adsorbed over the surface of the super-short carbon nanotube ( [ 8 ] cyclophenacene ) . In these systems, the Li atoms can be adsorbed stably on the nanotube, as revealed by their considerable adsorp-tion energies(84. 0-106. 2 kJ/mol) . Besides, when adsorbing one to two alkali Li atoms, the first hyperpo-larizability of the carbon nanotube can be effectively improved, where the β0 value can be significantly increased from zero to the range of 3. 42 ×103-8. 29 ×103 a. u. , owing to the occurrence of charge transfer process from the Li atom to the nanotube. Comparatively, when increasing the number of the adsorbed Li atoms to three, the β0 value can be further enhanced sharply, even to as large as 2. 59×106 a. u. , which can be attributed to the formation of the excess electron. Moreover, the distance between the adsorbed Li atoms can also play an important role in effecting the first hyperpolarizabilities of systems. This work can provide some new valuable insights for designing the new type of high-performance NLO materials based on the carbon nanotubes.