Keggin型磷钨酸复合TiO_2染料敏化太阳电池的制备及性能

Fabrication and performance of dye-sensitized solar cells base on Keggin phosphotungstic acid-TiO_2 composite

采用浸渍负载法制备Keggin型磷钨酸(PW_(12))-TiO_2粉体,再与TiO_2混合,通过刮涂法得到PW_(12)/TiO_2薄膜。利用场发射扫描电镜(FESEM)、X射线衍射(XRD)、紫外-可见吸收光谱等分析PW_(12)/TiO_2薄膜的形貌、光吸收性质,并以D102为染料敏化组装成太阳电池,对其光电转化性能进行研究。结果表明:PW_(12)-TiO_2粉体平均粒径为20 nm,TiO_2为锐钛矿型,通过两步法制备的PW_(12)/TiO_2薄膜保持磷钨酸结构不变;磷钨酸的引入不仅没有改变TiO_2薄膜的形貌和结构,反而促进了电子在薄膜内部的传输和电子空穴的分离,降低了电子在薄膜中传输阻力,提高了电池的光电转换效率。当PW_(12)质量分数为3.3%时,由PW_(12)/TiO_2薄膜组装的DSSC最大短路电流密度(JSC)为9.52 m A/cm2,最高总能量转换效率(η)为3.5%。

PW_（12）-TiO_2 powders were prepared by impregnation method base on Keggin phosphotungstic acid（PW_（12））-TiO_2 composite. The PW_（12）/TiO_2 films were fabricated using PW_（12）-TiO_2 powders mixed with TiO_2 by doctor-blade method.The morphologies and optical absorption properties of the films were characterized by field emission scanning electron microscopy（FESEM）, X-ray diffraction（XRD） and UV-vis spectrum. The performances of D102 dye-sensitized solar cells based on PW_（12）/TiO_2 films were studied. The results show that the average size of PW_（12）/TiO_2 powders is 20 nm, TiO_2 exhibits primarily anatase type, and the PW_（12）/TiO_2 films prepared by the two-step method keeps the structure of phosphotungstic acid. The introduction of phosphotungstic acid does not change the morphology and structure of TiO_2 films, but promotes the separation of electrons and holes, reduces the resistance of electron transport in the film, thus improves the photoelectric conversion efficiency of the cell. When the mass fraction of PW_（12） is 3.3%, the maximum short-circuit current density（JSC） of DSSC based on PW_（12）/TiO_2 film is 9.52 m A/cm2, and the maximum total energy conversion efficiency（η） is 3.5%.