设计并制作了大面积高效全柔性染料敏化太阳能电池(DSCs).通过引入光散射层或施加机械压力,DSCs的光电转化效率有了大幅度提高.实验室小面积(0.4 cm×0.4 cm)柔性DSCs的光电转化效率达到5.50%.大面积(2 cm×3 cm,活性面积为2.7 cm~2)DSCs的光电转化效率从未进行处理的1.52%上升到1.81%和2.50%,分别提高了20.0%和66.7%.5 cm×7 cm面积的DSCs(活性面积为16.2 cm~2)的光是转化效率在未做任何优化处理的条件下达到了1.60%(光强40 mW·cm~(-2)).同时,本文对提高光电转化效率的机理进行了深入研究.电化学阻抗测试结果表明,加压法能明显减小电池的内部串联电阻(R_s)及TiO_2/染料/电解液界面间的传荷电阻(R_(ct)).扫描电镜结果也显示加压后TiO_2粒子之间粘结更加紧密,更利于电子在TiO_2薄膜中的传输及染料的吸附.另外,900 h的长期稳定性实验结果表明,制作的柔性DSCs的各项光电性能参数均无明显下降.该实验结果为柔性染料敏化太阳能电池的基础研究和大面积产业化技术研究奠定了基础.
Highly efficient large scale flexible dye-sensitized solar cells(DSCs) were successfully designed and fabricated.By the introduction of a light scattering layer or pressure,the DSC efficiency was greatly improved.The flexible DSCs with a small surface area(0.4 cm×0.4 cm) gave a high energy conversion efficiency of 5.50%.The energy conversion efficiencies of large area DSCs(2 cm×3 cm,active area of 2.7 cm~2) improved from 1.52%to 1.81%and 2.50%,which is an increase of 20.0%and 66.7% compared with the DSCs prepared without any treatment.The 5 cm×7 cm DSCs(active area of 16.2 cm~2) without any optimization showed an energy conversion efficiency of 1.60%under a sunlight intensity of 40 mW·cm~(-2).The mechanism for the improvement in efficiency was also studied.The results of electrochemical impedance spectroscopy(EIS) demonstrated that the pressure method can significantly reduce the series resistance(R_s) and the charge transfer resistance(R_(ct)) in the TiO_2/dye/electrolyte interface.Scanning electron microscopy(SEM) showed that the TiO_2 particles were far more closely connected after pressing, which was helpful for electron transport in the TiO_2 network as well as for dye adsorption.In addition,the photovoltaic parameters of these flexible DSCs were found to be stable after the 900 h stability tests.The experimental results obtained for these flexible DSCs can be used as a foundation for further basic research and for industrialization technical research.