蒽类衍生物的电荷传输性质

以具有较高迁移率的对称取代类蒽的衍生物{2,6-二2-(4-戊基苯基)乙烯基]蒽,DPPVAnt;2,6-二-噻吩蒽,DTAnt;2,6-二2-己基噻吩]蒽,DHTAnt}为研究对象,采用密度泛函理论的B3LYP方法,在6-31G(d)的基组水平上研究了三种蒽类衍生物的分子结构、电子结构、重组能和电荷传输积分,采用Einstein关系式计算了室温下的载流子迁移率,并与蒽的相关计算结果进行了比较.DPPVAnt是较好的空穴传输材料,其空穴迁移率为0.49cm2·V-1·s-1;DHTAnt有利于电子传输,其电子迁移率为0.12cm2·V-1·s-1;而DTAnt是一种较好的双极性材料,其空穴迁移率和电子迁移率分别为0.069和0.060cm2·V-1·s-1.计算得到的迁移率与实验结果处于同一数量级.三种蒽类衍生物的电子重组能与蒽的相近,而空穴重组能均大于蒽的空穴重组能,大小顺序为蒽DPPVAntDTAntDHTAnt.这与计算的迁移率结果不一致,说明分子的堆积结构决定材料的电荷传输性质.

Charge Transport Properties of Anthracene Derivatives

The molecular geometries, electronic structures, reorganization energies, and charge transfer integrals of three anthracene derivatives {2,6-bis2-(4-pentylphenyl)vinyl]anthracene, DPPVAnt; 2,6-bis-thiophene anthracene, DTAnt; 2,6-bis2-hexylthiophene]anthracene, DHTAnt} were investigated by density functional theory at the B3LYP/6-31G(d) level. Their mobilities at room temperature were estimated using Einstein relations and compared with the calculated mobility of anthracene. DPPVAnt is a good hole-transporting material with a hole mobility as high as 0.49 cm2·V^-1·s^-1; DHTAnt is an electron-transporting material with an electron mobility of about 0.12 cm2·V^-1·s^-1; DTAnt is a bipolar material with its hole and electron mobilities being 0.069 and 0.060 cm2·V^-1·s^-1, respectively. The calculated mobilities were of the same magnitude as those obtained by experimental measurements. The reorganization energies for the electrons of the three derivatives are almost the same as that for anthracene but the reorganization energies for the holes of the three derivatives are larger than that of anthracene and they follow the order: anthracene