The Study On Preparation Of Metallic-Oxide-Modified TiO₂Film Dye-Sensitized Solar Cells

Solar cells have been the most effective form to use solar power. The siliconsolar cells own the highest photoelectric efficiency, but it is hindered bycomplicated process and high cost. The dye-sensitized solar cells （DSSC） isconsidered one of the promising candidate because it can exhibit low cost andfriendly environment.The nanoparticles of TiO₂were made by hydrothermal method in this paper.Organic polymer dispersant of PVA added into above-mentioned sol and the TiO₂porous film had a better flat surface by doctor-blade method, then the MgO/TiO₂and ZnO/TiO₂core-shell films were made on the basis of absorption theory. Thestructure characterizations were x-ray diffraction, Scanning electron microscopic,and laser particle size analysis. The optical properties were tested byspectrophotometer and I-V curves tester. According to aforesaid tests, we canmeasure particle size, crystalline types, surface appearance, absorbance character,doping performance and I-V curves. The results were shown in below.The TiO₂by hydrothermal method was an anatase structure and the particleswere nanoscale sizes. According to doctor-blade method, we could make a TiO₂photoanode film with flat surface and uniform structure, the thickness was about10μm. The TiO₂porous film was composed of nanoscale clusters. Thephotoanode film with PVA could effectively form holes and reduce thephenomenon of particle reunion, so the transmission of electrons and theadsorption of dye were easier. These were results of photoelectric property:conversion efficiency was3.15%, short-circuit current was7.8mA/cm2, open- circuit voltage was0.493V, fill factor was61.04%.TiO₂photoanode film was modified by doping the wide band gapsemiconductor of MgO, ZnO respectively, according to change the dipping timeand sintering temperature, we could gain good core-shell films. The resultsshowed that: MgO/TiO₂and ZnO/TiO₂core-shell films owned better surfaceflatness. According to absorption, the MgO and ZnO were into the TiO₂surfacestructure, two oxides showed smaller reunion. These were results of MgO/TiO₂core-shell film photoelectric property: conversion efficiency was4.04%, short-circuit current was9.32mA/cm2, open-circuit voltage was0.505V, fill factor was64.3%. These were results of ZnO/TiO₂core-shell film photoelectric property:conversion efficiency was3.93%, short-circuit current was10.68mA/cm2, open-circuit voltage was0.487V, fill factor was56.68%.Comparing with above-mentioned photoanodes, the results showed thatMgO/TiO₂core-shell photoanode conversion efficiency was increased28.25%comparing with pure TiO₂, ZnO/TiO₂core-shell photoanode conversionefficiency was increased24.76%comparing with pure TiO₂. The results indicatedthat the MgO/TiO₂and ZnO/TiO₂core-shell films could reduce therecombination and improve the transmission rate of photogenerated electrons.The photoelectric efficiency was enhanced. Under the surface modification ofMgO/TiO₂core-shell photoanode, the photoelectric property was better.