Band-edge engineered hybrid structures for dye-sensitized solar cells based on SnO2 nanowires
Band-edge engineered hybrid structures for dye-sensitized solar cells based on SnO2 nanowires
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DOI：
10.1002/adfm.200800099
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发表时间：
2008-08-22
影响因子：
19
通讯作者：
Sunkara, Mahendra K.
中科院分区：
文献类型：
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作者：
Gubbala, Suresh;Chakrapani, Vidhya;Sunkara, Mahendra K.
在这篇报告中，我们首次发现基于SnO2纳米线的染料敏化太阳能电池的开路电压为560 mV，比基于SnO2纳米颗粒的电池高出200 mV。这是由于与纳米粒子相比，纳米线的平带电位更负，这是通过在高光强下进行的开路光电压测量确定的。该纳米线由高度互连的SnO2纳米线基体包覆TiO2纳米粒子组成，其开路电压为720 mV，效率为4.1%，而纯SnO2纳米线基体的效率为2.1%。SnO2纳米线基体的电子传递时间常数比TiO2纳米线基体低一个数量级，复合时间常数比TiO2纳米线基体高约100倍。基于杂化结构的DSSCs的效率更高归因于SnO2相对于TiO2的能带边缘位置和SnO2纳米线中更快的电子传递。
In this report, we show for the first time that SnO2 nanowire based dye sensitized solar cells exhibit an open circuit voltage of 560 mV, which is 200 mV higher than that using SnO2 nanoparticle based cells. This is attributed to the more negative flat band potential of nanowires compared to the nanoparticles as determined by open circuit photo voltage measurements made at high light intensities. The nanowires were employed in hybrid structures consisting of highly interconnected SnO2 nanowire matrix coated with TiO2 nanoparticles, which showed an open circuit voltage of 720 mV and an efficiency of 4.1% compared to 2.1% obtained with pure SnO2 nanowire matrix. The electron transport time constants for SnO2 nanowire matrix were an order of magnitude lower and the recombination time constants are about 100 times higher than that of TiO2 nanoparticles. The higher efficiency observed for DSSCs based on hybrid structure is attributed to the band edge positions of SnO2 relative to that of TiO2 and faster electron transport in SnO2 nanowires.