Pakpoom Chansri

Synthesis and characterization of TiO2 on ZnO-nanorod layer for high-efficiency electrochemiluminescence cell application

In this research paper, we present the fabrication of an electrochemiluminescence (ECL) cell with TiO2 on ZnO-nanorod electrodes via the dip-coating technique. The TiO2 nanoparticles coated on ZnO nanorods (TiO2-ZNRs) were grown on transparent conductive oxide (TCO) glass by the dip-coating technique. The electrode of TiO2-ZNRs for ECL cells has the structure F-doped SnO2 (FTO) glass/Ru(II) complex [Ru(bpy)32+]/TiO2-ZNRs/FTO glass. The TiO2-ZNRs were coated on FTO glass by spin-coating and dip-coating methods. The X-ray diffraction system, scanning electron microscope, and spectral brightness analyzer were used to confirm the successful formation of the structure and the morphological properties. The threshold voltage at the start of light emission was 2.25 V for TiO2-ZNRs and was lower than 3.25 V for bare FTO. The threshold voltage was l2.5 V for ZNRs. The electrical and optical properties of the TiO2-ZNRs ECL cell were 30.76 cd/m2 light intensity, 0.067 mA output current, 0.268 cd/A (at 9.67 mA/cm2) current efficiency, and 0.068 lm/W ECL efficiency at 5 V and 60 Hz. The peak intensity of the TiO2-ZNRs-based ECL cell at a wavelength of 621 nm exhibited a dark orange color and was independent of the type of electrode used. The use of TiO2-ZNRs could improve the ECL efficiency and long-lifetime stability.

Effects of electrical and optical properties of thickness condition of ZnO nanorod array layer for efficient electrochemical luminescence cell device

In this paper, we report on electrochemical luminescence (ECL) cells with a ZnO nanorod (ZNR) layer. The investigated ECL cells were composed of F-doped SnO2 (FTO) glass/Ru(II)/ZNRs/FTO glass, which used a ZNR layer as an electrode and the Ru(II) complex [Ru(bpy)32+] as a light-emitting material. The ECL cells were fabricated by changing the thickness of ZNRs from 5 to 12.5 µm. The luminescence property of the ECL cells was strongly affected by the variation in the thickness of the ZNR layer. The threshold voltage for the light emission from the ECL cells was 2 V for 10 µm thick ZNRs, which was lower than that of the thickness of the ECL cells without a ZNR layer. Also, the intensity of luminance from the ECL cells with ZNRs was much higher than that from the ECL cells without ZNRs at the same operating voltage. The efficiency of the ECL cells without ZNRs measured at 3 V was 0.0049 lm/W, while those of the ECL cells with ZNRs were 0.0121, 0.0157, 0.0354, and 0.024 lm/W for the ZNRs layer thicknesses 5, 7.5, 10, and 12.5 µm, respectively. However, the peak light intensity at the wavelength was 623 nm which had not affected the all ZNRs thicknesses. The best lifetime of the ECL cells with these thicknesses was 40 min for ZNRs 10 µm. The use of the ZNR layer in the ECL cells significantly improves the luminescence performance.

Effect of Thickness in Carbon Nanotube Electrode Layer for Electrochemi-Luminescence Cells Applications

The nanoelectrode layer in electrochemi-luminescence (ECL) cells can be improved the performance of light intensity. In this work, the ECL cells were fabricated using carbon nanotubes (CNT) and Ru(II) complex as a luminescent material. We reported to the effect of the thickness of the CNTs layer in ECL cell. The produced ECL cell consists of F-doped SnO₂(FTO) glass/Ru(II)/thickness of CNTs/FTO glass. At 3.5 V, the measured highest current and highest luminance of CNTs-based on ECL cells was 48 mA and 15.02 cd/㎡ at CNT-5 μm. The maximum of ECL efficiencies was 0.00893 lm/W for CNT-5 μm. When, the applied voltage increases at 4-5 V is causing to maximum ECL efficiency for CNTs-based on ECL cell. The peak intensity of thickness of CNTs-based on ECL cell was ∼620 nm of CNTs and ∼625 nm of without CNT, which is a similar color and responded dark orange color, were not affected to the added electrode material. The ECL cell with CNTs showed optimum for light emission was the thickness of CNT-5 μm electrode. The use of CNTs-based on ECL cell significantly improves the ECL efficiency and long-term stability.