SiO_2 Opal光子晶体结构周期数对TiO_2染料敏化太阳能电池光电性能的影响

The effect of SiO_2 Opal periodicity on the photoelectric performance of TiO_2 dye-sensitized solar cell

通过在N719敏化的纳米晶二氧化钛膜上耦合SiO_2 Opal光子晶体,以此复合膜为光阳极,以敏化二氧化钛与无序SiO_2的复合膜为参比膜,考察了SiO_2 Opal光子晶体结构周期数对电池光电性能的影响。SiO_2 Opal光子晶体的结构周期数由制备光子晶体时的沉积液浓度控制。实验结果表明复合光子晶体后,电池的短路电流密度ISC和能量转化效率Eff明显提高,且光子晶体周期数越多,提高率越大,当SiO_2 Opal结构周期数增加至20层时,ISC和Eff与参比膜相比分别增加了91%和164%。IPCE分析表明光电性能提高的原因在于当光子晶体带隙与N719吸收峰重合时,利用光子带隙反射与光局域效应可提高N719对波长530nm光的吸收率。即光子晶体可有效提高吸光材料在光子带隙处的吸光率,且随着光子周期数增加,提升效果越显著。

The effect of photonic-crystals（ PC） periodicity on the photoelectric performance of dye-sensitized solar cells was studied. The anodes of solar cells was the N719 dye-sensitized nanocrystalline TiO_2 film which was coupled with one layer of SiO_2 Opal PC with different periodicity. The periodicity of SiO_2 PC was controlled by the concentration of silica suspension in vertical deposition. It was shown that the Short circuit current density（ISC）and the energy conversion efficiency（Eff）of the DSSC increased with the SiO_2 PCs periodicity. When the SiO_2 Opal increased to 20 layers,compared with reference film,ISCand Eff increased by 91% and 164%,respectively. The results of IPCE analysis indicated that the improved performance of DSSCs was mainly attributed to the enhanced light-harvest of the N719 dye near 530 nm by the light reflection at photonic band gap and photon localization of SiO_2 Opal. The Photonic crystal can effectively improve the light-harvest at the photonic band gap. The more the periodicity of the PC is,the stronger the effect of its photon localization is.