石墨烯量子点/CdS/CdSe共敏化太阳能电池

Graphene Quantum Dots/Cd S/Cd Se Co-Sensitized Solar Cells

以三维锐钛矿TiO_2微球为上层光散射层材料,以商业纳米TiO_2为下层连接材料,采用刮刀法制备了一种新颖的双层TiO_2薄膜,并应用于量子点敏化太阳能电池(QDSSC)。其中,石墨烯量子点(GQDs)采用滴液法引入,Cd S/Cd Se量子点采用连续离子层吸附法(SILAR)制备。采用场发射扫描电镜、透射电镜、X射线衍射、紫外-可见漫反射光谱及荧光光谱对样品进行表征。实验还制备了Cd S/Cd Se量子点敏化及石墨烯量子点/Cd S/Cd Se共敏化太阳能电池,并研究了石墨烯量子点及Cd S不同敏化周期及对电池性能影响。研究结果表明,石墨烯量子点及Cd S不同敏化周期对薄膜的光学性质、电子传输及载流子复合均有较大影响。优选条件下,TiO_2/QGDs/Cd S(4)/Cd Se电池的光电转换效率为1.24%,光电流密度为9.47 m A/cm^2,显著高于TiO_2/Cd S(4)/Cd Se电池的这些参数(0.59%与6.22 m A/cm^2)。这主要是由于TiO_2表层吸附石墨烯量子点后增强了电子的传输,减少了载流子的复合。

Using three-dimensional anatase TiO2 microspheres as light scattering overlayer and commercial TiO2 nanocrystalline as connecting underlayer, novel double-layered TiO2 films were prepared by a doctor blade method for quantum dots sensitized solar cell（QDSSC） application. The graphene quantum dots（GQDs） were introduced by dripping, and the Cd S/Cd Se quantum dots were deposited by continuous ion-layer adsorption（SILAR） method, respectively. The prepared quantum dots sensitized thin films were characterized by field emission scanning electron microscopy, transmission electron miscroscopy, X-ray diffraction, Uv-vis diffuse reflectance spectra, and fluorescence spectra. Cd S/Cd Se quantum dots sensitized and GQDs/Cd S/Cd Se co-sensitized solar cells were fabricated, respectively. And the effects of GQDs and Cd S quantum dots with different deposition cycles on the microstructures and the photovoltaic performance of the double-layered TiO2 QDSSCs were investigated and discussed. The results revealed that the introduced GQDs and the Cd S deposition cycle obviously influenced the optical properties of the double-layered TiO2 film. The electron transfer and charge-recombination process are also affected by the Cd S deposition cycle and the introduced GQDs. Optimally, the conversion efficiency and photocurrent density of the Ti O2/QGDs/Cd S（4）/Cd Se solar cell is 1.24% and 9.47 m A/cm^2, respectively, which are higher than those（0.59% and 6.22 m A/cm^2, respectively） of the Ti O2/Cd S（4）/Cd Se cell. This is due to the effective electrons transport and reduced charge recombination within the co-sensitized cell.