Na, K And Mg Preparation And Properties Of Co-doped Zno Films

ZnO film is aⅡ-Ⅵdirect compound semiconductor with wide band gap energy of 3.37eV and a exciton binding energy 60meV at room temperature. ZnO thin film is used widely and effectively in the fields of surface acoustic wave devices, solar cell, gas sensors, varistors and so on because of its excellent piezoelectrical performance. It also has the tremendous potential applications for ultraviolet detectors,LEDs, LDs. Al-doped ZnO(ZAO) thin films are emerging as an alternative potential candidate for ITO (Sn-doped In2O3) flims recently not only because of their comparable optical and electrical properties to ITO films, but also because of their higher thermal and chemical stability under the exposure to hydrogen plasma than ITO. P-type doping of ZnO thin films also attract lots of attentios.This paper intro domestic and foreign current research situation about ZnO films, this paper mainly using sol-gel method, with duces Zn(CH3COO)2·2H2O do solute, C2H5OH as solvent, with HN(CH2CH2OH)2 do stabilizer, Preparation (Na, Mg):ZnO and (K, Mg):ZnO films with a glass as underlay. Test films of XRD, SEM, optical properties and electrical properties, this paper following conclusions:(1) respectively with spin coating method and tiras ZnO films, prepare legal system compares SEM diagram, found tiras method was samples of uniform surface more superior to spin coating, morphology al.chemical strategies for samples. (2) using tiras method in various process conditions preparation (Na, Mg):Zn,film, film structure and performance will suffer doping concentration, annealing temperature, coating layer etc. Craft condition the influence:doped ZnO films diffraction peak and standard diffraction compared to the small Angle peak direction, lattice distortion, with making the concentration of the ions increased film (002) diffraction peak slacken, thin-film resistors lead with making the concentration of the ions increased decreases increase, Mg ions concentration edge dramatically increase film absorb blue shift, absorption wavelength decrescent, forbidden band width greatens. Annealing temperature for 500℃, film, best crystallinity high temperature is too low against the growth of thin films, coating layer increased (002) crystal diffraction peak also increase consequently. (3) This experiment with KCl and MgCl2 as doping source,when K ions film or Mg ions participation in the quantity is high surface will appear impurities accumulation; Appropriate impermeability K ion can improve performance, increase the pervious to light thin film film optical bandgap; K ion doped with the increased amount of (002) crystal diffraction peak to small Angle direction, the peak half tall wide greaten, grain size, average particle size decreases continuously in 30-40nm between, film alloy decreases. Film best annealing temperature for 550℃, when film showed good (002) orb is optimal orientation,, grain size, making 90nm than (to):Zn, Mg, high temperature mainly because film annealing K ion radius than making ion radius is big, need the higher temperature for more energy to good happen diffusion and migration. Coating layer changes in the film has good (100) crystal preferentialness orientation.