外电场作用下ZnO分子的结构特性研究  

Structural properties of ZnO molecules under an external electric field

作　　者：安跃华[1] 熊必涛[2] 邢云[1] 申婧翔[1] 李培刚[1] 朱志艳[1] 唐为华[3] 

机构地区：[1]浙江理工大学光电材料与器件中心,杭州310018 [2]浙江科技学院理学院应用物理系,杭州310023 [3]北京邮电大学理学院信息光子学与光通信国家重点实验室,北京100876

出　　处：《物理学报》2013年第7期148-153,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51072182;51172208;11247314);浙江省自然科学基金(批准号:Y1110519);浙江省大学生科技创新活动计划(批准号:2011R406062;2012R406053);浙江科技学院科研启动基金(批准号:F501108C01)资助的课题~~

摘　　要：本文以6-311++g(d,p)为基组,采用密度泛函理论的B3P86方法优化得到了ZnO分子的基态稳定构型,并计算了不同外电场(0.05—0.05a.u.)下ZnO基态分子的稳定电子结构,研究外电场对ZnO基态分子键长、总能量、电荷分布、能级分布、能隙及红外光谱的影响.结果表明:外加电场的大小和方向对分子结构和电子特性均有明显影响.随着正向外加电场的增加,ZnO基态分子的平衡键长先减小后增加,而分子总能量、振动频率和红外光谱的强度均先增加后减小.分子的最高占据轨道能量EH、最低未占据轨道能量EL和能隙Eg始终处于减小趋势,因而占据轨道的电子更容易被激发至空轨道.这一结果可为ZnO分子的电致发光机理研究提供一定的理论参考.Based on the equilibrium structure obtained, the ground states of ZnO molecule under external electric fields ranging from -0.05 to 0.05 a.u. were optimized using the density functional theory B3P86 at 6-311＋＋g（d,p） level. Effects of electric fields on the bond length, total energy, charge distribution, energy levels, HOMO-LUMO gap and the infrared spectrum of the ground states of ZnO molecule have been investigated systematically. The results show that the molecular geometry and electronic properties were dependent on the magnitude and direction of the external electric field considerebly. With the increase of electric field along the molecular axis O-Zn, the equilibrium bond length first decreased and then increased, while the total energy, the harmonic frequency and infrared spectrum first increased and then decreased. But the HOMO, LUMO energy levels and the energy gap decreased monotonically, indicateing that the molecule could be excited easily by a specific electric field. We think that the present results are useful for better understanding the physical mechanism underlying the electroluminescence properties of ZnO molecule.

关 键 词：ZNO 外电场 结构参数 激发 

分 类 号：O561[理学—原子与分子物理]