Ultrasonically sprayed ZnO:Co thin films: Growth and characterization

Investigations on electrical conductivity and dielectric properties of Na doped ZnO synthesized from sol gel method

“…The variation of activation energy with Na content is represented in Fig.5 It is clearly seen that conductivity activation energy of the ZnO is lower than those of the Na doped ZnO NPs. Besides, the obtained values are so high than those reported in other papers [43,44]. However, these values are in the same range (1.17-1.29 eV) than those reported for ZnO doped with Fe which is known to create acceptor levels in ZnO band gap [45].…”

Effect of Sn doping on properties of transparent ZnO thin films prepared by thermal evaporation technique

“…High temperature dependence of electrical conductivity for ZnO and ZnO:Sn thin films as depicted by the ln σ Vs 1000/T ( Figure 6), shows obvious change in thermal activation energy from 0.72eV to 0.13 eV on Sn doping. This indicates that a donor level is formed closer to the conduction band in ZnO:Sn probably due to formation of defects when Sn 4+ is substituted at a few Zn 2+ sites, thus producing the higher conductivity [28][29][30].…”

Studies on Photoresponse and LPG sensitivity of transparent Al doped ZnO thin films prepared by thermal evaporation technique

“…The estimation of optical band gap Eg is performed following the Tauc's method relating absorption coefficient α to photon energy hν according to the expression [22] αhν = A(hν -Eg) 1/2 ……………………………….. [23]where heavy doping of Al (12at%) produces a redshift in bandgap. The increase in bandgap on doping compared to pure ZnO is attributed toBurstein-Moss effect that shifts the absorption edge to higher energy side [7].The decrease in bandgap of the sample with 10 at% Al may be due to heavy defect formation which produces intermediate defect levels [24].…”