| Infrared transparent and conductive oxides will become the indispensable components of optic-electric devices in the astronautics and aeronautics. However, the traditional infrared transparent and conductive oxide is unavailable to have both the high infrared transmittance and superior electric properties. Based on the above background, mid-infrared transparent and conductive In2O3 and In2O3:Sn films were prepared by plasma assisted magnetron sputtering, which are crystalline. The influence of pulsed bias voltage(|-400 V|<|Vp|<|-900 V|)on the crystal structure, optical-electric properties and surface energy state were studies systematically. After that, far-infrared transparent and conductive Y2O3:Ru films were prepared by using magnetron sputtering with dual targets. Investigating the correlation between the Ru doping concentration, substrate and the chemical elements, structure and electric-opt properties were conducted. Carrier concentration were coupling with the plasma frenquency for In2O3 and In2O3:Sn films. The Y2O3:Ru films were deposited on the Zn S substrate, realizing the transparent and conductive functionality in far-infrared range.The crystal structure of In2O3 and In2O3:Sn films, which prepared by plasma assisted magnetron sputtering, is closely linked to the growth parameters. With the increase of plused bais voltage, it is obviously to observe the change in surface morphology, proving that this method is an useful way to modify the surface contents. Amorphous-crystal transformation come true when the pulsed bias voltage changes. Both In2O3 and In2O3:Sn films have superior optical and electric properties. The electric properties of In2O3 and In2O3:Sn films increased with the increase of pulsed bias voltage. The film resistivity decreased firstly and then went up, while the electronic mobility shows the opposite trend. With the increase of pulsed bias voltage the oxygen vacancies reduced, causing the lower carrier concentration. In contrast, the increased pulsed bias voltage induced the transform from Sn2+ to Sn4+ in the films, resulting in the higher carrier concentration. Both In2O3 and In2O3:Sn films had high transmittance of 80 % in visible range, the band gap follows the Burstein-Moss law. At room temperature, the In2O3 and In2O3:Sn films have the optimal electric and optical properties at the pressure of 0.5 Pa and |Vp|=|-700 V|. Furthermore, hardness results showed the improved hardness of films can be obtained by the route of plasma assisted deposition. The work function of In2O3 and In2O3:Sn films measured by UPS can be modified by plasma assisted deposition. When the bias voltage is in the range of |-600 V|<|Vp|<|-700 V|, oxygen vacancie on the In2O3 surface reduced, leading to the increased work function. While the bias voltage increased to the range of |-700 V|<|Vp|<|-900 V|, the transformation between <222> orientation and <400>occurred resulting the higher wok function. In contrast, the higher work function of In2O3:Sn was mainly due to the transformation of Sn2+ to Sn4+ state after the plasma bombardment. Higher energy ions bombardment induced more Sn-O bond, more oxygen on the surface, causing large work function.In the preparation of Y2O3:Ru by dual magnetron sputtering, it was found that radio frequency power applied on the Ru target and the substrate temperature were the most important growth parameters. When the power increased, the deposition rate increases. All the as-deposited Y2O3:Ru films were amorphous. XPS results showed Y2O3:Ru films contained Ru4+-O and Ru6+-O bonds. As the Ru concentration increased, the intensity of Ru6+ increased and decreased for Ru4+. Hall measurement showed Y2O3:Ru belonged to the n-type semiconductor. Increasing Ru doping concentration, the films had more defects, causing in creased carrier concentration and decreased mobility. At higher temperature, the films showed lower carrier concentration and higher mobility due to the reduction of interstitial atoms and oxygen vacancies in the films.Ultar violet-visible-near infrared spectrophotometry displayed higher Ru doping concentration induced lower transmittance in visible range due to the stronger scattering. When the substrate temperature increased form room temperature to 600 ℃, the transmittance of films in the visible range increased gradually, indicating the improved atom order, which can be explained that higher temperature remove some vacancies and provided more energy for atom mobility, during this process, the carrier concentration increased or decreased causing the increasing and decreasing band gap.Finally, the coupling relationship between carrier concentration and plasma frequency of In2O3, In2O3:Sn and Y2O3:Ru thin films by magnetron sputtering assisted plasma exposure were investigated. Moreover, the optimized Y2O3:Ru was deposited on the Zn S substrate and compared with the other known far-infrared transparent and conductive materials. |
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