Structural and electro-optical properties of electrospun Cu-Doped ZnO thin films

Pure and Cu-doped ZnO thin films (TFs) were synthesized on glass substrates via the electrospinning method, and the effects of Cu concentration on electro-optical and structural properties were investigated. The nanofibers (NFs) changed to cross-linked nanoparticles (NPs) via calcination at 400 degrees C. XRD results indicate that Cu2+ was successfully incorporated into the ZnO host to form a hexagonal wurtzite structure. The crystallography of Cu-doped ZnO (CZO) was systematically investigated; it was found that both c/a ratio and compressive lattice strain increased. The photoluminescence (PL) behavior of CZO TFs revealed that the excitonic and redshifted UV emissions were manipulated by Zn-i, O-i, V-zn, O-zn and V-o defect states. Optical absorption measurements showed excellent transmission percentages (above 87%) in the visible light range. The optical band gap of ZnO TFs decreased from 3.3 eV to 3.2 eV after incorporation of Cu. The results of this study show that electrospun CZO TFs has immense potential for use in electro-optical applications.