Preparation Of Nanosilicate Electrode Prepared By Metal Sulfide Sensitized TiO 2 And Its Application In Solar Cells

With the development of global economy and the rapid growth of population, the energy crisis and environmental pollution have become two major problems in modern society. To solve these problems, so far, the most effective way is developing and utilizing new energy sources.The quantum dot sensitized solar cells have attracted many researchers due to their advantages,such as the no-toxic, high conversion efficiency, low prices, simple fabrication and so on. In this work, we firstly fabricated the anatase titanium dioxide nanotubes on the titanium sheet by electrochemical anodic oxidation. Then, we used the metal sulfide quantum dots to sensitize TiO2 nanotubes, getting the composite electrodes. The photoelectrochemical properties of the quantum dots to sensitize TiO2 electrodes were investigated.(1) Titanium dioxide/cadmium sulfide(TiO2/CdS) and Titanium dioxide/bismuth trisulphide(TiO2/Bi2S3) composite electrodes were prepared via successive ionic layer adsorption and reaction. The electro chemical properties of the composite electrodes with different cycles were studied by means of electrochemical workstation. The results show that with the increasing of sensitization cycles, the photocurrent of the two kinds of composite electrodes were increased first and then decreased. When the number of the sensitization cycles is 20, the photocurrent density and the photoelectric conversion efficiency of the TiO2/CdS electrode and TiO2/Bi2S3 electrode all reached the maximum value, the TiO2/CdS composite electrode conversion efficiency is about 11.87 times as much as the TiO2 electrode, and the TiO2/Bi2S3 composite electrode conversion efficiency is about 19.87 times as much as the TiO2 electrode.(2) We prepared TiO2/CdS/Bi2S3 and TiO2/Bi2S3/CdS composite electrodes through successive ionic layer adsorption and reaction in which CdS and Bi2S3 two quantum dot were co-sensitized on TiO2 nanotubes, and its photochemical properties were measured. The results show that the photochemical properties of TiO2/CdS/Bi2S3 electrode is not only better than the TiO2/Bi2S3/CdS composite electrode but also stronger than the TiO2/CdS composite electrode,and the photoelectric conversion efficiency of TiO2/CdS/Bi2S3 composite electrodes is about 1.79 times of TiO2/CdS composite electrode and about 2.1 times as much as the TiO2/Bi2S3/CdS composite electrode.(3) The Cu2ZnSnS4-(CZTS) materials were prepared through the high temperature hydrothermal. Then on the basis of TiO2 nanotubes, the TiO2/CZTS composite electrodes were made by spin coating method. The composite electrodes’ electrochemical performance were tested under different temperature of electrolyte. The results demonstrate that the TiO2/CZTS electrodes photocurrent density increased with the rising of temperature at first and then decreased in the 5-45?C range. The photocurrent density, photoelectric conversion efficiency andthe pseudo-first-order rate constant are all the minimum at 5?C, however, when the temperature increased to 15?C, all of them reached their highest value, and the conversion efficiency is about1.63 times as much as when the temperature is 5°C.