Comparative study of quaternary Mg and Group III element co-doped ZnO thin films with transparent conductive characteristics

• Published in: Thin solid films 2014-11, Vol.570, p.321-325
• Main Authors: Kim, In Young, Shin, Seung Wook, Gang, Myeng Gil, Lee, Seung Hyoun, Gurav, K.V., Patil, P.S., Yun, Jae Ho, Lee, Jeong Yong, Kim, Jin Hyeok
• Format: Article
• Language: English
• Subjects: Aluminum; Carrier density; Columnar structure; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Field emission; Magnesium; Magnetron sputtering; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Quaternary compound; RF magnetron sputtering; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Thin films; Transparent conducting oxide; Wurtzite; Zinc oxide
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2014.02.109

Mg and Ga co-doped ZnO (MgxGayZnzO, x+y+z=1, x=0.05, y=0.02 and z=0.93, MGZO), Mg and Al co-doped ZnO (MgxAlyZnzO, x+y+z=1, x=0.05, y=0.02 and z=0.93, MAZO), Mg and In co-doped ZnO (MgxInyZnzO, x+y+z=1, x=0.05, y=0.02 and z=0.93, MIZO), Mg doped ZnO (MgxZnyO, x+y=1, x=0.05 and y=0.95, MZO) and pure ZnO thin films have been prepared on the glass substrates by RF magnetron sputtering. Their structural, morphological, compositional, electrical, and optical properties were characterized. The X-ray diffraction patterns showed that all the thin films were grown as a hexagonal wurtzite phase with c-axis preferred orientation without secondary phase. The (0002) peak positions of MGZO, MAZO and MIZO thin films were not significantly changed. The cross-section field emission scanning electron microscopy images of MGZO, MAZO and MIZO thin films showed that all the thin films have a columnar structure with dense morphology. The MGZO thin film showed the best electrical characteristics in terms of the carrier concentration (3.7×1020/cm3), charge carrier mobility (8.39cm2/Vs), and a lower resistivity (1.85×10−3Ωcm). UV–visible spectroscopy studies showed that the MGZO, MAZO and MIZO thin films exhibit high transmittance over 85% in the visible region. The MGZO thin films showed wider optical band gap energy of 3.75eV. •Mg and Group III Co-doped ZnO thin films were prepared by RF sputtering technique.•The Co-doped ZnO thin films showed better properties than those of un-doped.•The Mg and Ga Co-doped ZnO (MGZO) thin film showed the best properties.•The MGZO thin films showed the band gap of 3.75eV and resistivity of 1.83×10−3Ωcm.