High quality ITO thin films grown by dc and RF sputtering without oxygen

Abstract

High quality indium tin oxide (ITO) thin films were grown without oxygen by both dc and RF magnetron sputtering techniques on glass substrates. The effects of substrate temperature, film thickness and sputtering method on the structural, electrical and optical properties of the as-grown films were investigated. The results showed that the substrate temperature had substantial effects on the film properties, in particular on the crystallization and resistivity. When the substrate temperature was increased to 150 • C, crystallization in the (2 2 2) plane started appearing for both dc and RF sputtered films. We additionally found that with further increments of substrate temperature, the preferred crystallization orientation changed differently for dc and RF sputtered films. Optical transmission in the visible region for a film thickness of 70 nm was found to be above 85%. The bandgap was calculated to be about 3.64 eV for the substrate temperature of 150 • C for a 70 nm thick film. The value of the bandgap increased with respect to the increment in film thickness as well as substrate temperature. We also measured the temperature dependence of the resistivity and Hall coefficient of the films, and calculated the carrier concentration and Hall mobility. Very low room temperature resistivities for dc and RF magnetron sputtered grown films of about 1.28 × 10 −4 cm and 1.29 × 10 −4 cm, respectively, were obtained.

Highly efficient charge collection in dye-sensitized solar cells based on nanocomposite photoanode filled with indium-tin oxide interlayer

“…The measured carrier mobility of the ITO granular film using Hall effect testing instrument is~0.23 cm 2 /Vs, very close to the reported value [25] but far lower than that of ITO continuous film (~10-70 cm 2 /Vs) [29,30]. The global carrier mobility for the ITO granular film reflects the average value throughout the film and is therefore significantly affected by interparticle transfer, surface scattering, and trapping.…”

Hybrid crystalline-ITO/metal nanowire mesh transparent electrodes and their application for highly flexible perovskite solar cells

“…32,33 After 4 h of annealing, however, the characteristic peaks of c-ITO (2θ = 30.5°and 2θ = 35.5°assigned to 222 and 400, respectively) were observed. 10,34 These peaks imply that the top ITO layer was successfully crystallized by the annealing process.…”

Active material, optical mode and cavity impact on nanoscale electro-optic modulation performance

“…A similar mode profile can be seen from Figure 2D′ for the case of bulk ITO structure, which is a waveguide made of ITO on top of a SiO 2 substrate ( Figure 2D). Index modulation for bulk ITO can in principle be done via thermo-refractive effects, but the effect is rather slow (~ms); here the carrier concentration in ITO increases with annealing temperature [46,47]. A second mechanism for index tuning of ITO is a capacitive carrier modulation-based mechanism discussed above [3,10,14,15,21,26,27] Thus, for biasing purposes, a 5 nm gating oxide layer is included (for every mode considered for electrostatic consistency).…”