LV Shmeleva. She made mathematical calculations, take part in the discussing of the results and conclusions. Both authors TGF-beta inhibitor read and approved the final manuscript.”
“Background ZnO semiconductor attracted considerable research attention in the last decades due to its excellent properties in a wide range of applications. ZnO is inherently an n-type semiconductor and has a wide bandgap of approximately 3.37 eV and a large exciton binding energy of approximately 60 meV at room temperature. As mentioned

above, ZnO is a promising semiconductor for various applications such as UV emitters and photodetectors, light-emitting diodes (LEDs), gas sensors, field-effect transistors, and solar cells [1–6]. Additionally, ZnO resists radiation, and hence, it is a suitable semiconductor for space technology applications. Recently, ZnO nanostructures have been used to produce short-wavelength optoelectronic devices due to their ideal optoelectronic, physical, and chemical properties that arise from a high surface-to-volume ratio and quantum confinement effect [6–8].

Among the ZnO nanostructures, ZnO nanorods showed excellent properties in different applications and acted as a main component for various nanodevices [1, 2, 9–11]. FDA approved Drug Library Previous research showed that the optical and structural properties of ZnO nanorods can be modified by doping with a suitable element to meet pre-determined needs [12, 13]. The most commonly investigated metallic dopants are Cu and Al [13–15]. Specifically, copper is known as a prominent luminescence activator, which can

enhance the green luminescence Gefitinib datasheet band by creating localized states in the bandgap of ZnO [16–19]. Previous research showed that Cu has high ionization energy and low formation energy, which speedup the incorporation of Cu into the ZnO lattice [16, 20]. Experimentally, it was observed that the addition of Cu into ZnO-based systems has led to the appearance of two defective states at +0.45 eV (above the valence band maximum) and −0.17 eV (below the conduction band minimum) [21, 22]. Currently, a green emission band was observed for many Cu-doped ZnO nanostructures grown by different techniques [23, 24]. Moreover, Cu as a dopant gained more attention due to its room-temperature ferromagnetism, deep acceptor level, some similar properties to those of Zn, gas sensitivity, and enhanced green luminescence [15–17]. However, there are several points that have to be analyzed such as the effect of the copper source on the structural, morphological, and optical properties of Cu-doped ZnO. Moreover, the luminescence and the structural properties of Cu-doped ZnO nanorods are affected by different parameters such as growth conditions, growth mechanism, post growth treatments, and Cu concentration. Despite the promising properties, research on the influence of Cu precursors on Cu-doped ZnO nanorod properties remains low.