Structural defects and photoluminescence studies of sol–gel prepared ZnO and Al-doped ZnO films

ZnO and Al-doped ZnO (AZO) films were synthesized using sol–gel spin-coating method. The powder XRD analysis revealed the stress relaxation mechanism upon Al doping in ZnO film. The reduction in the imaginary part of the dielectric constant and suppression of deep level acceptor type octahedral oxygen interstitial defects account for the reduction in carrier concentration in AZO with respect to ZnO. Electrical conductivity measurements and grain boundary conduction model are used to quantify the carrier concentration. From the Commission Internationale d’Eclairge diagram of ZnO and AZO, color parameters like dominant wavelength, color purity and luminosity are determined and reported for the first time. The prepared ZnO and AZO films show considerable blue emission. These films can be used for white light generation.