外延氧化铟薄膜中的表面缺陷及其对薄膜电导率的影响

ransparent conductive oxide (TCOs) are mostly wide bandgap n-type semiconductor materials, such as zinc oxide, indium oxide, tin oxide. This kind of material even without doping, the film conductivity is much higher than in the shape of the block of conductivity, however, the source of its conductivity has been controversial. In recent years, Lany et analyzed area of the body and the surface layer of band structure of indium oxide film through theoretical calculation, finding that the oxygen vacancy material surface area may be a thin film of high conductivity and carrier concentration of the main source of micro. However, in the current study, the existence of surface oxygen deficiency and the influence of thin film photovoltaic properties are still a lack of adequate experimental basis. In order to validate the surface oxygen vacancy on the dominant role of the conductivity of membrane, we prepared epitaxial indium oxide thin films with different thicknesses on YSZ (100) single crystal substrates. After that, we use photoluminescence spectrum analysis and process of thin film thickness of the defect mode of relation to obtain information of surface oxygen defect, and further through the electrical transport measurements to extract the different thickness of film resistivity and carrier concentration. We found that with the decrease of the thickness of the thin film, we observe the broadening rocking curve and the narrowing of the band gap size and penetration in indium oxide thin films are high dislocation density of buffer layer and with the increase of surface layer and layer ratio and highlights the surface effect. In addition, the electrical conductivity of ~9 nm thick indium oxide film was high one order of magnitudeof than the thiker films. Our experimental results confirmed the TCOs oxygen defects do exist in the surface layer of material, and dominated the characteristics of high conductivity.