Preparation And Characterization Of Molybdenum Doped Zinc Oxide Transparent Conducting Oxide Films

Transparent conducting oxide films (TCOs) with high optical transparence in the visible range, high optical reflectance in the infrared range and high electrical conductivity have been widely used in flat panel displays, electronic devices, organic light-emitting diodes and solar cells. Among all the TCOs, indium tin oxide (ITO) has been widely used because of its low resistivity, high transmittance and high work function. However, ITO has some disadvantages such as a high-energy barrier for holes injection at the ITO/hole transport layer interface and the diffusion of indium into the organic layers in organic light-emitting diodes. Recently, ZnO has been actively investigated as an alternate material to ITO because it is nontoxic, inexpensive, and abundant compared with ITO. Moreover, ZnO is chemically stable in hydrogen plasma that is commonly used in the fabrication of TFT-LCDs. Al, Ga, In, Zr, B and rare earth-doped ZnO films have been grown by various deposition techniques. However, looking for new materials still remains interesting and attractive.The ionic radii of Mo⁶⁺ is 6.2 × 10^-11 m, and that of Zn²⁺ is 7.4 × 10^-11 m, thus it is theoretically possible for Mo⁶⁺ to substitute Zn²⁺ in the MZO. Moreover, there is a valence difference of 4 between Mo⁶⁺ and Zn²⁺, which is quite attractive because one dopant atom can contribute more electrons to the electrical conductivity. MZO films should have high carrier mobility because there is fewer dopant in MZO than in other doped oxides at the same carrier concentration.A new transparent conducting oxide film of molybdenum-doped zinc oxide (MZO) has been prepared by RF magnetron sputtering method on glass substrate. The structural and chemical properties were measured with XRD, SEM, AFM and XPS. The electrical properties were measured with Hall effect measurements using the Van der Pauw...