Study On Preparation And Properties Of Silver Oxide Thin Film

In rencent years, silver oxide (AgxO) films have received more and more attention due to their potential application in optical and magneto-optic storage by using their themal decomposition effect. Nowadays, the high threshold of their thermal decomposition themperatures (TTDT) has been a bottleneck for the industrialization in the future. Hence, the research is focused on the TTDT lowering by the preparation of single-phased Ag2O film.In this thesis, the AgxO films were deposited by direct current magnetron sputtering using different reactive pressures (RP) and sputtering powers (SP) on the purpose of obtaining the optimal condition of single-phased Ag2O film. Moreover, the films thermal decomposition and TTDT value was studied by using traditional chamber thermal treatment under vacuum condtion. The effects of the deposition parameter and thermal treatment temperature was intensively studied on the structure, surface morphology and optical properties of the AgxO and single-phased Ag2O films by using scanning electron microscopy, x-ray diffractometry and spectrophotometry.The main results are listed as follows:(1) The phase structure of the AgxO films apparently evolves from biphased (AgO+ Ag2O) to single-phased (Ag2O), and to biphased (Ag2O+AgO) structure with increasing the RP and SP values, respectively. Particularly, the single-phased Ag2O film were deposited at RP=2.5 Pa and SP=105 W, respectively, which effectively lowered the TTDT of AgxO film. The creative result prents a direction to deal with the appliction problem in optical and magneto-optical disks. The change of the optical properties with increasing the RP and SP values may be attributed to the film's structural evolution and to the increasing film thickness.(2) The optical band gap of the AgxO films decreases from 3.1 eV to 2.73 eV with increasing the SP, indicating that the AgxO film is a direct band gap semiconductor. The optical band gap of the single-phased Ag2O films deposited at SP=105 W is about 2.86 eV.(3) The evolution of the Ag2O film's surface morphology from dense to loose surface occurred after the thermal treatment under vacuum condition, which is attributed to the thermal decomposition reaction of Ag2O and the diffusion and escape from film surface of O atoms. The film's phase structure obviously changes after the thermal treatment. A small number of Ag particles begin to exhibit in the Ag20 film at a thermal treatment temperature of 300℃, and Ag2O phases is completely transformed into Ag at a thermal treatment temperature of 475℃.