Effect of Li-doped concentration on the structure, optical and electrical properties of p-type ZnO thin films prepared by sol–gel method

Li-doped ZnO thin films were deposited on n-type Si(1 0 0) substrates with sol–gel method. Then the deposited ones were analyzed in the X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that these films have polycrystalline wurtzite-structure and high c-axis preferred orientation. The analyses on the deposited thin films tested in the Hall measurements at room temperature show that these thin films are p-type electrical conductivity. The optimized results obtained at 15.0 at.% Li-doped concentration are 1.10 Ω cm in electrical resistivity, 10.70 cm 2/V s in Hall mobility and 5.32 × 10 18 cm −3 in hole concentration, respectively. The photoluminescence (PL) spectra show that these thin films have strong emission near ultraviolet (UV) and violet light. However, the defect-related deep level emission is weak in visible regions. The effects of Li-doping concentration on the structural, optical and electrical properties are discussed as well in this paper.