Influence of doping novel perimidine ruthenium complexes on structural, optic, and residual stress properties of ZnO thin films

Abstract Novel perimidine ruthenium complexes ([Ru(L1-2)(p-cymene)Cl]Cl) were synthesized and these synthesized Ruthenium (Ru) complexes were added to ZnO at content of 2, 4, 6 wt.% to fabricate Ru-doped ZnO thin films by the sol-gel spin-coating method. These films were characterized using XRD, SEM, FT-IR, UV-Vis, and Photoluminescence (PL) spectra. All of the films possessed a hexagonal wurtzite structure, according to XRD data. The observed stress was compressive, except for the A4 sample, and ranged from 0.21 GPa to 2.117 GPa as the ruthenium content increased from 0–6%. Residual stress values of Ru-doped ZnO thin films showed a lower value than pure ZnO film. It was obtained that the crystalline quality tended to improve as well as lower residual stress with increasing Ru amount. In the visible range, all the films exhibited approximately transmittance greater than 70%. Further, the optical bandgap was 3.20 eV for pure ZnO and all Ru-doped films' bandgap had between 2.76 and 3.18 eV. This research shows that new high conjugated structures are promising as dopant materials for the ZnO thin film, and good crystalline and optical properties could be obtained from the Ru doped ZnO films prepared by sol-gel for nano-optoelectronic devices.