A detailed research for determination of Er/Gd co-doping effect in ZnO-NPs thin films on optical, electrical and crystallographic properties

Abstract

Undoped, Er and Gd doped ZnO transparent semiconductor thin films were coated on non-alkaline glass using the sol–gel dip-coating method. Methanol and ethanolamine (MEA) were chosen as solvents and stabilizers. Er doping concentration was maintained at 5%. The effects of both different dopants and different dip numbers on the optical, electrical and structural properties of ZnO thin films were analyzed. According to the XRD patterns, hexagonal structure was seen in all films. The optical transmittance of impurity elements doped ZnO thin films increased with the increasing of Gd doping. High transparency was determined to doped films in the visible region. The electrical properties of the Er/Gd co-doped ZnO thin films were measured by Van der Pauw Hall measurements technique that determined the bulk carrier concentration, the Hall mobility and the resistivity at room temperature. Er and Gd doped films shown lower Hall mobility and resistivity than undoped ZnO thin films. In the bulk carrier concentration, it was seen that there was an increase in 5 dip and 10 dip, while it decreased in 20 dip.