Wide band gap characteristic of quaternary and flexible Mg and Ga co-doped ZnO transparent conductive thin films

Abstract

Transparent conductive and flexible Mg and Ga co-doped ZnO (MGZO) thin films were prepared on poly-ethylene terephthalate (PET) by RF magnetron sputtering technique at room temperature. The effects ofdifferent working pressures on the structural, chemical, morphological, optical and electrical propertiesof MGZO thin films were investigated. X-ray diffraction results indicate that all the MGZO thin films weregrown as polycrystalline wurtzite structures without secondary phases such as MgO, Ga2O3, MgGa2O4,or ZnGa2O4. The MGZO thin film prepared at 6 mTorr has the lowest value of full width at half maximum.A typical survey spectrum of all the MGZO thin films confirmed the presence of Mg, Ga, Zn and O. TheMGZO thin film prepared at 6 mTorr showed the widest optical band gap energy of 3.91 eV and lowestelectrical resistivity of 5.3 × 10−3 cm.