三维有序氧化钛中空球薄膜的制备及其光电性能

Synthesis and Photovoltaic Performance of Threedimensional Ordered TiO_2 Hollow Sphere Films

为了提高染料敏化太阳能电池(DSSC)的光电转化效率,以聚苯乙烯微球(290-300 nm)自组装形成的胶体晶体为牺牲模板制备了三维有序氧化钛中空球(3DOHS-Ti O2)薄膜材料,考察了以P25-Ti O2/3DOHS-Ti O2双层膜为光阳极的电池的光电转化特性。扫描电镜结果表明:3DOHS-Ti O2样品中的Ti O2中空球呈紧密六方排列,其球心距为260-270 nm,壁厚为40-50 nm,相邻的Ti O2中空球彼此之间通过孔洞相互连接;透射电镜结果表明:Ti O2中空球体由尺寸约为10 nm的锐钛矿相氧化钛颗粒组成,其壳壁上有由颗粒间堆积形成的介孔。光电性能测试结果表明:P25-Ti O2/3DOHS-Ti O2/DSSC的光电转化效率可达6.98%,明显优于常规的P25-Ti O2/DSSC(4.32%),其原因是双层膜光阳极中的3DOHS-Ti O2薄膜对太阳光散射和捕捉能力的增强。

To improve the properties of dye-sensitized solar cells （DSSC）, three-dimensional ordered TiO2 hollow spheres （3DOHS-TiO2） films were synthesized using polystyrene spheres （290-300 nm） colloidal crystals as sacrificial templates. The photoelectric conversion performances of the DSSC based on double-layered films P25-TiO2/3DOHS-TiO2 were investigated. SEM results show that the orderly arranged TiO2 hollow spheres form hexangular and square arrays, and the hollow spheres connect to their neighbors through pores. The center-center spacing of the 3DOHS-TiO2 is 260-270 nm, and the thickness of the hollow shells is 40-50 nm. TEM results show that the shell is composed of a lot of tiny particles resulting in a mesoporous framework. The mean size of the anatase TiO2 nanoparticles of the shells is ca.10 nm as estimated from the HRTEM image. By compared with the P25-TiO2 nanocrystalline DSSC （n=4.32%）, the DSSC based on the double-layered films P25-TiO2/3DOHS-TiO2 exhibit a higher photoelectric performance （n=6.98%）. The enhancement of the cell performance can be attributed to the enhancement of light harvesting of the light scattering ability of the layer 3DOHS-TiO2.