Tm-doped ZnO nanorods as a TCO for PV applications

In photovoltaic (PV) devices, a transparent conducting oxide (TCO) film is used as a transparent electrode which permits sun rays to reach to the photoactive semiconducting layers and also to collect the photo-generated electrons. Due to their electrical and optical properties zinc oxide (ZnO) based thin films and nanostructures are considered as an abundant and safer option for TCOs. In this study, undoped and thulium (Tm)-doped ZnO nanorods (NRs) were produced on glass substrates via spin coating and hydrothermal methods. The ZnO samples were described by X-ray diffractometry (XRD). Morphological features of the ZnO samples were investigated with scanning electron microscopy (SEM). It is observed that the all ZnO samples have nanorod shape. The average rods diameter is between 75 and 100 nm. Also, the rods length is found to be between 0.96 and 1.62 mm. Electrical properties of the ZnO samples were performed via four probe method. The conductivity increases with measurement temperature and Tm doping. Optical spectra of the ZnO samples were measured in UV-Vis range and the band gap (E-g) is found to be 3.35 eV. (C) 2018 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.