Selopal Gurpreet Singh, Wu Hui-Ping, Lu Jianfeng, Chang Yu-Cheng, Wang Mingkui, Vomiero Alberto, Concina Isabella, Diau Eric Wei-Guang
SENSOR Lab, Department of Information Engineering, University of Brescia, Via Valotti 9, 25133 Brescia, Italy.
CNR-INO SENSOR Lab, Via Branze 45, 25123 Brescia, Italy.
Sci Rep. 2016 Jan 7;6:18756. doi: 10.1038/srep18756.
We report the synthesis and characterization of new metal-free organic dyes (namely B18, BTD-R, and CPTD-R) which designed with D-π-A concept to extending the light absorption region by strong conjugation group of π-linker part and applied as light harvester in dye sensitized solar cells (DSSCs). We compared the photovoltaic performance of these dyes in two different photoanodes: a standard TiO2 mesoporous photoanode and a ZnO photoanode composed of hierarchically assembled nanostructures. The results demonstrated that B18 dye has better photovoltaic properties compared to other two dyes (BTD-R and CPTD-R) and each dye has higher current density (Jsc) when applied to hierarchical ZnO nanocrystallites than the standard TiO2 mesoporous film. Transient photocurrent and photovoltage decay measurements (TCD/TVD) were applied to systematically study the charge transport and recombination kinetics in these devices, showing the electron life time (τR) of B18 dye in ZnO and TiO2 based DSSCs is higher than CPTD-R and BTD-R based DSSCs, which is consistent with the photovoltaic performances. The conversion efficiency in ZnO based DSSCs can be further boosted by 35%, when a compact ZnO blocking layer (BL) is applied to inhibit electron back reaction.
我们报道了新型无金属有机染料（即B18、BTD-R和CPTD-R）的合成与表征，这些染料基于D-π-A概念设计，通过π连接部分的强共轭基团来扩展光吸收区域，并用作染料敏化太阳能电池（DSSC）中的光捕获剂。我们比较了这些染料在两种不同光阳极中的光伏性能：标准的TiO₂介孔光阳极和由分层组装纳米结构组成的ZnO光阳极。结果表明，与其他两种染料（BTD-R和CPTD-R）相比，B18染料具有更好的光伏性能，并且当应用于分层的ZnO纳米微晶时，每种染料的电流密度（Jsc）都高于标准的TiO₂介孔膜。采用瞬态光电流和光电压衰减测量（TCD/TVD）系统研究了这些器件中的电荷传输和复合动力学，结果表明，基于ZnO和TiO₂的DSSC中B18染料的电子寿命（τR）高于基于CPTD-R和BTD-R的DSSC，这与光伏性能一致。当应用致密的ZnO阻挡层（BL）来抑制电子反向反应时，基于ZnO的DSSC的转换效率可进一步提高35%。
