Significant progresses on quantum dot-sensitized solar cells (QDSCs) have been made by Dr. Shimao Wang and his colleagues from Laser Technology and Photoelectric Functional Materials Lab, Laser Technology Research Center, Anhui Institute of Optics and Fine Mechanics (AIOFM).
The team created a qualitative model (Fig. 1) of CdS/CdSe quantum dot distribution in TiO2 photoanode of QDSCs through investigating the element distribution of Cd, S, and Se and the average size of QDs in TiO2 nanoparticle films with different thickness. According to the model, they put forward three feasible approaches for optimizing TiO2 photoanode, optimized the thickness of TiO2 photoanode, and obtained a relatively high power conversion efficiency of 3.26±0.10%. This achievement was published in Journal of Power Sources (2015, 273, 645-653).
In addition, the vacuum thermal evaporation (VTE) technique was utilized to prepare copper sulfide (CuxS) films on fluorine-doped tin oxide (FTO) substrate for the first time in research of counter electrodes (CEs). It shows that the electrocatalytic activity and stability of the obtained VTE-CuxS films as CEs for QDSCs are both obviously better than Cu2S CEs based on brass foil and Pt CEs based on FTO substrates (Fig. 2, 3). And it is more exciting that this approach could improve the preparation of the conventional CuxS CEs, solve the problem of brass foil substrates susceptible to corrosion, and meet the requirement of high efficient and stable CEs in the future industry production of QDSCs ,which is published in Electrochimica Acta (2015, 154, 47-53).
The above work was supported by the National Natural Science Foundation of China, the National Basic Research Program of China, and the Key Lab of Novel Thin Film Solar Cells, Chinese Academy of Sciences.
Fig. 1. Qualitative model of CdS/CdSe quantum dot distribution in TiO2 electrode.
Fig. 2. Tafel plots of the symmetrical cells of VTE-CuxS, Brass-Cu2S, and Pt CEs.
Fig. 3. CV curves of 30 cycles for the symmetrical cells of Pt, Brass-Cu2S, VTE-CuxS CEs.
