聚合物材料PPV及PPyV光电性质的第一性原理研究

First-Principles Studies of Optical Properties of PPV and PPyV

运用密度泛函理论平面波赝势方法(PWP)和广义梯度近似(GGA),研究了聚对苯乙烯(poly-paraphenylene vinylene,PPV)材料的结构、电学性质以及光学性质。分析其电子态分布与结构的关系,给出了聚合物PPV掺杂前后体系的态密度及能带结构。在标准条件下,PPV单胞内的原子均在同一平面上,其结构常数如键长和键角与实验及理论值符合较好。将PPV的一个C原子用N原子替代,即聚乙烯吡啶(PPyV),计算发现,其能带图与PPV材料相比有细微差别,相对于PPV,吸收谱的波形基本相同,而吸收峰明显发生蓝移。通过比较可知,研究所得结果与现有文献相符。

Based on the plane- wave pseudo- potential and generalized gradient approximation,thestructure,electric property and optical property of poly- para-phenylene vinylene（PPV）were studied.Analyzed the relationship between the distribution and structure of electronic states. Gave out the densityof states and the band structure of system before and after doping of PPV. Under the standard conditions,the atom in PPV cell are in the same plane,the structure constants such as bond lengths and bond anglesare consistent between experiment and theory. Replaced the C atom with N atom in PPV,formed poly p-pyridyl vinyline（PPyV）,after calculating,found out the energy band has slight difference with PPV materials,and the wave form of absorption spectrum are nearly the same,however,obvious blue shiftoccurs in absorption peak. The results comply with the existing literature.