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For the direct formation of two-dimensional (2D) tungsten disulfide (WS2) thin films with higher productivity and lower process temperature than conventional chemical vapor deposition (CVD), WS2 thin films were deposited on a sapphire glass substrate by direct current (DC) sputtering and subsequent rapid thermal processing (RTP). From the optical investigation by atomic force microscopy (AFM), it was possible to stable surface and observe more improvements at higher RTP temperatures irrespective of sputtering power. Hall measurements showed higher resistivity and lower carrier density at higher DC sputtering power in spite of the constant carrier mobility. Raman spectrum results showed lateral vibration of tungsten and sulfur atoms at temperatures above 700 °C. The directly formed WS2 thin films showed the improvements in structural and electrical characteristics as a semiconductor layer. [ABSTRACT FROM AUTHOR]

Mg-doped ZnO [(Zn, Mg)O] thin films were prepared by atomic layer chemical vapor deposition (ALCVD) process with different Mg content, using diethyl zinc, biscyclopentadienyl magnesium, and water as the metal and oxygen sources, respectively. The ratio of Mg to Zn was varied by changing the pulse ratio of MgCp 2 to DEZn precursor to study its effect on the properties of (Zn, Mg)O thin films. From the experimental results, it was shown that the grain size of the ZnO-like hexagonal phase (Zn, Mg)O decreased as the Mg content increased. But the transmittance and optical band gap of (Zn, Mg)O films increased with the increase of the Mg content. In addition, the effect of the substrate temperature on the properties of (Zn, Mg)O films was also investigated. The deposition rate, transmittance, and crystallinity of (Zn, Mg)O films increased as the substrate temperature increased. But its band gap decreased slightly with the increase of substrate temperature. [ABSTRACT FROM AUTHOR]

Abstract: The indium tin oxide (ITO) film was deposited on PET (polyethylene terephthalate) film using in-line pulsed DC magnetron sputtering system with different duty ratios. The reverse time and the frequency of pulsed DC power were changed to obtain the different duty ratios. From the electrical and optical properties such as the sheet resistance, resistivity, thickness and transmittance, the pulsed DC sputtered ITO/PET films were also superior to the DC sputtered ITO/PET films. The reverse time had little effect on the properties of the ITO/PET film and the frequency of pulsed DC power had an immerse effect on the properties of the ITO/PET films. The optimal ITO/PET film was obtained when the frequency was 200kHz, the reverse time was 1μs, and the duty ratio was about 80%. [Copyright &y& Elsevier]

Abstract: We report an electrical bistable switching property in two terminal organic memory cells fabricated with a sandwich structure of Alq3/Liq/Alq3, Alq3/10% doped Liq, and mixed compounds of Alq3, PVP, and Zn nitrate hexahydrate nanoparticles (NPs) as the active component between two external electrodes. The conductance switching to two states such as ON/OFF states in the ITO/Alq3/Liq/Alq3/Al devices shows their conductance difference by ON/OFF ratio of several orders (103) in magnitude and outstanding stability having a tendency to remain in that states for an extended period of times (∼24h). Also, the high and low conductivity states of the memory cells can be exactly obtained by applying a negative voltage pulse to write or a positive voltage pulse to erase, respectively. The memory cells have been maintained during numerous (106) writing–erasing cycles in ambient conditions without serious degradation of the device performance. [Copyright &y& Elsevier]

For the improvement of structural and electrical characteristics of diamond, phosphorus implantation was done during the growth of diamond films. The diamond films implanted with phosphorus were subsequently grown again by microwave plasma chemical vapor deposition (MPCVD). Fabricated diamond films were structurally and electrically characterized. From the results of field emission scanning electron microscope (FESEM) and atomic force microscope (AFM), the implanted diamond samples showed the smoother surfaces and new smaller grains on diamond grains as a result of subsequent growth after implantation. It is thought that the small grains pile up among large grains and compensate rough surfaces of diamond which are caused by large grain size of diamond. The sizes of small grains can be also related to the dose of implanted phosphorus ions. Improved field emission characteristics were obtained in the case of the higher ion dose. It is considered that these results are due to the increased emission area from small grains, and more defects formed in diamond. [Copyright &y& Elsevier]