Liu Zonghao, Li Wenhui, Topa Sanjida, Xu Xiaobao, Zeng Xianwei, Zhao Zhixin, Wang Mingkui, Chen Wei, Wang Feng, Cheng Yi-Bing, He Hongshan
Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, People's Republic of China.
ACS Appl Mater Interfaces. 2014 Jul 9;6(13):10614-22. doi: 10.1021/am5022396. Epub 2014 Jun 24.
We report on an experimental study of three organic push-pull dyes (coded as zzx-op1, zzx-op1-2, and zzx-op1-3) featuring one, two, and three fluorene units as spacers between donors and acceptors for p-type dye-sensitized solar cells (p-DSSC). The results show increasing the number of spacer units leads to obvious increases of the absorption intensity between 300 nm and 420 nm, a subtle increase in hole driving force, and almost the same hole injection rate from dyes to NiO nanoparticles. Under optimized conditions, the zzx-op1-2 dye with two fluorene spacer units outperforms other two dyes in p-DSSC. It exhibits an unprecedented photocurrent density of 7.57 mA cm(-2) under full sun illumination (simulated AM 1.5G light illumination, 100 mW cm(-2)) when the I(-)/I3(-) redox couple and commercial NiO nanoparticles were used as an electrolyte and a semiconductor, respectively. The cells exhibited excellent long-term stability. Theoretical calculations, impedance spectroscopy, and transient photovoltage decay measurements reveal that the zzx-op1-2 exhibits lower photocurrent losses, longer hole lifetime, and higher photogenerated hole density than zzx-op1 and zzx-op1-3. A dye packing model was proposed to reveal the impact of dye aggregation on the overall photovoltaic performance. Our results suggest that the structural engineering of organic dyes is important to enhance the photovoltaic performance of p-DSSC.
我们报道了一项关于三种有机推拉染料（编码为zzx-op1、zzx-op1-2和zzx-op1-3）的实验研究，这些染料在p型染料敏化太阳能电池（p-DSSC）的供体和受体之间具有一个、两个和三个芴单元作为间隔基。结果表明，增加间隔基单元的数量会导致300纳米至420纳米之间的吸收强度明显增加，空穴驱动力略有增加，并且染料到NiO纳米颗粒的空穴注入率几乎相同。在优化条件下，具有两个芴间隔基单元的zzx-op1-2染料在p-DSSC中优于其他两种染料。当分别使用I(-)/I3(-)氧化还原对和商用NiO纳米颗粒作为电解质和半导体时，在全太阳光照（模拟AM 1.5G光照，100 mW cm(-2)）下，它表现出前所未有的7.57 mA cm(-2)的光电流密度。这些电池表现出优异的长期稳定性。理论计算、阻抗谱和瞬态光电压衰减测量表明，与zzx-op1和zzx-op1-3相比，zzx-op1-2表现出更低的光电流损失、更长的空穴寿命和更高的光生空穴密度。提出了一种染料堆积模型来揭示染料聚集对整体光伏性能的影响。我们的结果表明，有机染料的结构工程对于提高p-DSSC的光伏性能很重要。
