Study On The Compact Layer In Photoanode Of Dye-sensitized Solar Cells

Compact layers have significant meanings in increasing short-circuit currentdensity (Jsc) of dye-sensitized solar cells (DSSC). Compact layers used to prevent theelectron recombination are introduced onto the fluorine-doped tin oxide（FTO）glassby a spin-coating method. This article focus on the preparation of compact layers andthe mechanism research.This article uesd two methods to prepare TiO2compact layers. A hydrothermalmethod to prepare the TiO2nanopatticles used butyl titanate as precusor and a novelsol-gel method to prepare the TiO2sol directly. With the aid of the electrochemicalanalysis, we concluded that the novel sol-gel could prepare8~10nm TiO2compactlayer particles and the TiO2layers were flat and compact, they also have goodblocking effect to prevent the contact between the conductive glass and the electrolyte.The sol-gel method is simple and cost effective, which do not require hightemperature and high reaction pressure. The short-circuit current density (Jsc) andsolar energy conversion efficiency () are improved by15.1%and25.6%, respectively,after introducing three TiO2compact layers to DSSCs from our prepared TiO2sol viathe spin-coating method.Three ZnO compact layers and two TiO2compact layers were introduced onconductive glass to fabricate the novel hierarchical compact layer by sol-gel method.Overall, the short-circuit current density, open-circuit voltage and solar energyconversion efficiency are enhanced by15.3%,3.7%and29.6%, respectively, relativeto the traditional DSSC without any blocking layers. The ZnO/TiO2blocking layerhas been characterized by electrochemical impedance spectroscopy, open-circuitvoltage decay and dark current measurement to reveal the mechanism of short-circuitcurrent density and open-circuit voltage improvement.