Jiang Dianlu, Darabedian Narek, Ghazarian Sevak, Hao Yuanqiang, Zhgamadze Maxim, Majaryan Natalie, Shen Rujuan, Zhou Feimeng
Department of Chemistry and Biochemistry, California State University Los Angeles, 5151 State University Dr., Los Angeles, CA, 90032, USA.
College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu, Henan, China.
Chemphyschem. 2015 Nov 16;16(16):3385-8. doi: 10.1002/cphc.201500641. Epub 2015 Sep 1.
In dye-sensitized solar cells (DSSCs), a significant dye-regeneration force (ΔG(reg)(0)≥0.5 eV) is usually required for effective dye regeneration, which results in a major energy loss and limits the energy-conversion efficiency of state-of-art DSSCs. We demonstrate that when dye molecules and redox couples that possess similar conjugated ligands are used, efficient dye regeneration occurs with zero or close-to-zero driving force. By using Ru(dcbpy)(bpy)2(2+) as the dye and Ru(bpy)2(MeIm)2(3+//2+) as the redox couple, a short-circuit current (J(sc)) of 4 mA cm(-2) and an open-circuit voltage (V(oc)) of 0.9 V were obtained with a ΔG(reg)(0) of 0.07 eV. The same was observed for the N3 dye and Ru(bpy)2(SCN)2(1+/0) (ΔG(reg)(0)=0.0 eV), which produced an J(sc) of 2.5 mA cm(-2) and V(oc) of 0.6 V. Charge recombination occurs at pinholes, limiting the performance of the cells. This proof-of-concept study demonstrates that high V(oc) values can be attained by significantly curtailing the dye-regeneration force.
在染料敏化太阳能电池（DSSC）中，有效的染料再生通常需要显著的染料再生驱动力（ΔG(reg)(0)≥0.5 eV），这会导致大量能量损失，并限制了当前最先进的DSSC的能量转换效率。我们证明，当使用具有相似共轭配体的染料分子和氧化还原对时，在零或接近零的驱动力下会发生有效的染料再生。以Ru(dcbpy)(bpy)2(2+)作为染料，Ru(bpy)2(MeIm)2(3+//2+)作为氧化还原对，在ΔG(reg)(0)为0.07 eV的情况下，获得了4 mA cm(-2)的短路电流（J(sc)）和0.9 V的开路电压（V(oc)）。对于N3染料和Ru(bpy)2(SCN)2(1+/0)（ΔG(reg)(0)=0.0 eV）也观察到了相同的情况，其产生了2.5 mA cm(-2)的J(sc)和0.6 V的V(oc)。电荷复合发生在针孔处，限制了电池的性能。这项概念验证研究表明，通过显著降低染料再生驱动力可以获得高的V(oc)值。
