Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan.
Phys Chem Chem Phys. 2011 Dec 21;13(47):20999-1008. doi: 10.1039/c1cp21762c. Epub 2011 Oct 20.
Novel sub-micro sized hexagonal clubs of ZnO (HC-ZnO), which are coated as a scattering layer (SL) for the photoanode of a DSSC, are synthesized. X-ray diffraction (XRD) patterns of the ZnO clubs show clear peaks corresponding to wurtzite crystal phase of ZnO. Scanning electron microscopic (SEM) images show that each club has two opposite hexagonal faces (parts) of unequal dimensions. High resolution transmission electron microscopic (HR-TEM) image of a single ZnO club reveals that the ZnO is single crystalline and has wurtzite crystal structure; the image indicates a lattice spacing (d) of 0.26 nm; this is ascribed to the (002) planar spacing of the hexagonal ZnO. A solar-to-electricity conversion efficiency (η) of 3.36% is achieved for the cell with the double layer (DL) film, which is 16% higher than that of the cell with only transparent layer (TL) of commercial ZnO (2.89%) and far higher than that of the cell with SL (0.05%). The η of the cell with the DL (3.36%) could further be improved to 4.28% through the modification of the DL surface with TiO(x). Incident photo-to-current conversion efficiency (IPCE) curves, UV-vis absorption spectra, energy dispersive X-ray (EDX) spectra, and electrochemical impedance spectra (EIS) are also used to substantiate the results.
新型亚微米尺寸的 ZnO（HC-ZnO）六棱柱体被合成，并作为 DSSC 光阳极的散射层（SL）。ZnO 六棱柱体的 X 射线衍射（XRD）图谱显示出对应于 ZnO 纤锌矿晶体相的清晰峰。扫描电子显微镜（SEM）图像显示，每个六棱柱体有两个不等尺寸的相对六边形面（部分）。单个 ZnO 六棱柱体的高分辨率透射电子显微镜（HR-TEM）图像显示，ZnO 是单晶的，具有纤锌矿晶体结构；图像显示出晶格间距（d）为 0.26nm；这归因于六方 ZnO 的（002）平面间距。具有双层（DL）薄膜的电池的太阳能-电能转换效率（η）达到 3.36%，比仅具有商业 ZnO 透明层（TL）的电池（2.89%）高 16%，比具有 SL 的电池（0.05%）高得多。通过对 DL 表面进行 TiO(x)修饰，DL （3.36%）的 η 可以进一步提高到 4.28%。入射光电流转换效率（IPCE）曲线、紫外-可见吸收光谱、能量色散 X 射线（EDX）光谱和电化学阻抗谱（EIS）也用于证实结果。
