Construction of a branched ZnO–TiO2 nanorod array heterostructure for enhancing the photovoltaic properties in quantum dot-sensitized solar cells
Construction of a branched ZnO–TiO2 nanorod array heterostructure for enhancing the photovoltaic properties in quantum dot-sensitized solar cells
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DOI：
10.1039/c4ra05736h
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发表时间：
2014-07
期刊：
影响因子：
3.9
通讯作者：
Bingkun Liu;Yanjun Sun;Dejun Wang;Lingling Wang;Lijing Zhang;Xueqiang Zhang;Yanhong Lin;T. Xie-T.-Xi
中科院分区：
文献类型：
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作者：
Bingkun Liu;Yanjun Sun;Dejun Wang;Lingling Wang;Lijing Zhang;Xueqiang Zhang;Yanhong Lin;T. Xie-T.-Xi
我们报道了一种简单的制备三维（3D）分支ZnO-TiO 2异质结纳米棒阵列使用两步水热法。该过程包括在FTO衬底上垂直生长TiO 2纳米棒阵列作为骨架，然后在金红石树干上轻松地溶液生长分支ZnO纳米棒。将CdS量子点修饰后的ZnO-TiO 2异质结纳米棒阵列用作量子点敏化太阳能电池的光阳极。与裸的TiO 2纳米棒阵列相比，分支的ZnO-TiO 2异质结纳米棒阵列提供了更高的用于QD负载的表面积和由ZnO纳米棒分支引起的更好的光散射。同时，在TiO 2-ZnO界面处形成的异质结促进了电子转移，减少了电子与电解质氧化物种的复合反应。结果表明，在厚度仅为1 μm的情况下，QDSC的光电转换效率达到0.73%，比使用裸TiO 2纳米棒阵列作为光阳极的QDSC提高了55%。
We reported a facile fabrication of three dimensional (3D) branched ZnO–TiO2 heterojunction nanorod arrays using a two-step hydrothermal method. This process included the vertical growth of TiO2 nanorod arrays on FTO substrates as backbones and then the facile solution growth of branched ZnO nanorods on the rutile trunks. After being decorated by CdS quantum dots (QDs), the branched ZnO–TiO2 heterojunction nanorod arrays were used as photoanodes in quantum dot-sensitized solar cells (QDSCs). Compared to the bare TiO2 nanorod arrays, the branched ZnO–TiO2 heterojunction nanorod arrays provided a higher surface area for QD loading and better light scattering arising from ZnO nanorod branches. In the meantime, the heterojunction formed at the TiO2–ZnO interface facilitated the electron transfer and reduced the recombination reactions of electrons with electrolyte-oxidized species. As a result, we got a conversion efficiency of 0.73% with the thickness of only 1 μm, which showed a 55% improvement over the QDSCs that used bare TiO2 nanorod arrays as photoanode.