ZnO纳米颗粒表面缺陷对有机太阳能电池性能的影响

Effects of ZnO nanoparticles surface defects on organic solar cell performance

用温度控制ZnO纳米颗粒粒径的大小,研究了颗粒粒径对表面缺陷的影响。由透射电镜(TEM)、紫外-吸收光谱和荧光光谱测试表明,随着反应温度升高,ZnO纳米颗粒的尺寸增加,比表面积显著下降,表面缺陷的体密度降低。将不同反应温度下的ZnO纳米颗粒应用于ITO/ZnO/P3HT:PCBM/MoO3/Ag结构的有机太阳能电池中,进一步研究了缺陷对电池性能的影响。实验结果表明,60℃下ZnO纳米颗粒薄膜作为电子传输层的器件效果最好,电池效率可以达到3.05%。这表明在一定范围内,ZnO纳米颗粒越大,缺陷密度越低,越有利于器件中电子的传输从而提高太阳能电池器件的短路电流密度和光电转化效率。

ZnO exhibits a remarkable potential application in organic solar cells as an electronic transfer layer. However,the large numbers of defects on nanomaterials surface will trap electron and then de- crease the photocurrent of the device. In this research, we fabricated different sizes of ZnO nanoparticles under different reaction temperatures. The impact of the particle size on the surface defects is further studied. The morphologies and optical properties are researched by transmission electron microscopy （TEM） ,ultraviolet-visible absorption spectra and the fluorescence spectra. Analysis results showed the size and the specific surface area increase with the increase of reaction temperature, while the defect density of ZnO nanoparticles is decreased. Finally, ZnO nanoparticles with different reaction temperatures were incorporated in the organic photovoltaic devices as electron conductive layer, and the optimized device （60 ℃ ） shows the highest power conversion efficiency of 3.05 %. It is indicated that the grown particles result in the decrease of surface defects density, which is favorable to the electron transfer and device performance improvement.