Investigation on the effect of Zr doping in ZnO thin films by spray pyrolysis

► Zr doped ZnO films were deposited by spray pyrolysis. ► Average transmittance of 5 at.% Zr doped ZnO film is ∼92% in the visible region. ► The crystalline quality was deteriorated with the increase of Zr doping. ► 3 at.% Zr doped ZnO film possesses lowest resistivity of 2 × 10−3 Ω cm. ► RMS and grain size decrease with the increase of Zr doping.