基于含氮、硫元素苯衍生物的有机染料敏化剂的理论研究

Theoretical studies of benzene derivatives based on organic dyes containing Nitrogen and Sulfur

采用密度泛函(DFT)和含时密度泛函(TD-DFT)理论方法计算了以苯及其衍生物作为π共轭桥的染料分子的基态和激发态的微观性质.研究结果表明,与参考敏化剂P0相比,3种新型敏化剂P1、P2和P3的基态几何结构和前线轨道分布与之十分相似.采用CPCM-TD-BHandHLYP/6-31+G(d)方法,模拟染料分子P1在二氯甲烷溶液中的最大吸收波长为502nm,比P0吸收峰显著红移.利用Marcus理论,经过近似计算发现,与其他敏化剂相比,P1分子间电荷传输速率(Ket)最快.因此,P1应该可以作为有希望的敏化剂应用于染料敏化太阳能电池(DSSC),而且其能量转化效率(η)应该高于以P0为染料的DSSC的效率.

The microscopic properties for ground and excited states of metal-free organic dyes based on benzene and its derivatives were studied by density functional theory （DFT） and time-dependent DFT （TDDFT）. The results reveal that the geometries and the spatial localization of the HOMO and LU- MO for the ground states of three novel dyes are deeply similar with dye P0. The maximum absorp- tion wavelengths （λmax） of dye P1 in CH2Cl2 solution is 502 nm calculated at CPCM-TD-BHandHL- YP/6-31＋G（d） level. The absorption peak of dye P1 is significantly red-shift compared to dye P0. Estimated from Marcus theory,the rate of intermolecular charge transfer （Ket） of P1 is faster than the other dyes. Therefore, our results show that molecule P1 is a promising candidate in the DSSC and the power conversion efficiency （7？） should be higher than that of the DSSC based on organic dye P0.