Structural, Optical and Electrical Properties of ZnO Thin Films Doped with Al, V and Nb, Deposited by r.f. Magnetron Sputtering

Abstract

Structural, optical and electrical properties of ZnO thin films doped with different elements (Al, Al + H, V, Nb), deposited by r.f. magnetron sputtering on glass substrates at different temperature Ts between 50 and 500 °C are studied. XRD spectra demonstrate a preferential (002) crystallographic orientation with the c-axis perpendicular to the substrate surface and grains sizes of about 19–29 nm. The value of band gap energy Eg is in the range of 3.49–3.58 eV for ZnO:Al, 3.51–3.58 eV for ZnO:Al:H, 3.44–3.47 eV for ZnO:V, and 3.28–3.44 eV for ZnO:Nb. The deposited ZnO films doped with Al, H, V and Nb have low resistivities of 1.6–2.2⋅10−3 Ωcm. The transparency of the studied films is about 85–90 % in the visible region. The obtained transparent conductive ZnO thin films can be applied in solar cells and other optoelectronic devices as TCO.