The Influence of Doping Perimidine Ruthenium Complexes on Structural, Optic, and Residual Stress Properties of ZnO Thin Films

Perimidine ruthenium complexes ([Ru(L1-2)(p-cymene)Cl]Cl) were synthesized and were used to produce 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. It was determined by XRD analysis that all films have a hexagonal wurtzite structure. The residual stress was generally compressive and ranged from - 2.117 to 1.4 GPa as the ruthenium content increased from 0 to 6%. The crystal quality tended to increase, and the residual stress reduced with increasing Ru content. In the visible range, all the films exhibited transmittance greater than 70%. Further, the optical bandgap was 3.20 eV for pure film and bandgap of Ru-doped films varied 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 for nano-optoelectronic devices.