SrTiO_3/α-Fe_2O_3异质结光阳极光电转换性能  

Enhancement in Photoelectric Conversion Properties of SrTiO_3/α-Fe_2O_3 Heterojunction Photoanode

作　　者：王耀明[1] 罗文俊[2] 欧阳述昕[2] 李朝升[1,3] 于涛[1] 邹志刚[1] 

机构地区：[1]南京大学物理系环境材料与再生能源研究中心 [2]南京大学材料科学与工程系 [3]南京大学固体微结构物理国家重点实验室,江苏南京210093

出　　处：《发光学报》2007年第2期277-281,共5页Chinese Journal of Luminescence

基　　金：国家自然科学基金(20373025;20528302);江苏省自然科学基金(BK2006718;BK2006127);教育部留学回国人员科研启动基金(2005383)资助项目

摘　　要：作为一类重要的光电极材料,α-Fe2O3在太阳能转化方面有着潜在的应用前景。但是,光生电子空穴对的再复合导致α-Fe2O3的光电量子产率很低。为了抑制光生电子空穴对的再复合,提高α-Fe2O3的光电量子产率,采用Spin-coating方法在透明导电玻璃FTO(SnO2∶F)衬底上制备了SrTiO3/α-Fe2O3异质结薄膜光电极,并对该光电极进行了XRD、SEM、紫外-可见透射光谱的表征。在三电极光电化学测试系统中对薄膜的光电流-电压特性、入射光子电流转化效率(Incident photon to current efficiency,IPCE)对波长的依赖性进行了表征。在相同的Xe灯照射条件下,SrTiO3/α-Fe2O3异质结光电极的光电流及IPCE值大于单一的SrTiO3、α-Fe2O3各自的光电流及IPCE值,这与理论预测的结论一致。The photoelectrochemical cells based on semiconductor-liquid junctions have attracted much attention because of their potential application, such as solar energy converters. In the cell system, it is important to produce the high efficiency photoelectrodes that are stable in aqueous solution and that absorb a significant portion of the solar spectrum effectively. Much effort has been done to find new materials and new electrode structures in order to produce efficient photoelectrodes. Along with its abundance and low cost, α-Fe2O3 has narrow band gap, strong absorptivity in the visible range and good stability in aqueous solution. So it has been of considerable interest in its use as a photocatalyst and a photoelectode. However, the photocurrent quantum efficiency of α-Fe2O3 is too low to limit its further application in converting solar energy. In general, recombination of electrons and holes cased by low mobilities of holes and trapping of electrons by oxygen-deficient iron sites are considered to be responsible for the low conductivities and poor photocurrent efficiencies of iron oxide photoelectrode. To suppress the recombination of electrons and holes thus to improve the photocurrent quantum efficiency,the semiconductor films of SrTiO3,α-Fe2O3 and their heterojunction SrTiO3/α-Fe2O3 were prepared on FTO （ SnO2： F on glass） substrates by the spin-coating method. The XRD pattern, SEM and transmission spectra of SrTiO3/α-Fe2O3 film photoanode were characterized in our experiments. The anodic photocurrent-potential characteristics and the action spectra were studied in a three-electrode cell employing the film electrode as the working electrode with the electrolyte Na2SO4 （0.2 mol/L, pH≈7.5 ）. It was found that under 0.3 V bias voltage, the photocurrent and the incident photon to current conversion efficiency （IPCE） of the SrTiO3/ α-Fe2O3 film was higher than that of SrTiO3 or α-Fe2O3 films alone, which is consonant with our theoretical calculation conclusions by using the standard CAST

关 键 词：异质结 光电极 光电化学电池 光电流 入射光子电流转化效率 

分 类 号：O472.8[理学—半导体物理]