Mechanisms and applications of cell electrochemical technique to prepare luminescent SrMoO4 thin films

Cell electrochemical technique is a novel film deposition method. With the improved cell device, the rate determining step, utilization ratio of molybdenum, and applications to deposit SrMoO4 thin films have been investigated. Researches on the relation between the overpotentials of electrodes and the currents in the circuit reveal that the rate determining step is the reduction of water during the deposition of SrMoO4 thin films. The rates of electrode reactions can be tailored by controlling the electrolyte temperature. The utilization ratio of molybdenum is up to 90%, while it is nearly 60% for constant current method. In addition, X-ray diffraction analyses show that the as-grown SrMoO4 thin films are well crystalline and have a scheelite structure; scanning electron microscopy examinations reveal that SrMoO4 crystals grow well in tetragonal tapers. These thin films show a broad emission band centered at 520 nm using an excitation wave of 230 nm at room temperature.