| dc.description.abstract | The 2 at.% Sn-doped ZnO nanorods with (002) preferred orientation were electrodeposited on a copper substrate (purity at 99.9%) in the present work. Influence of the H2O2 concentrations and deposition voltage on the microstructure and optical properties of the oxide film was of interest. Besides, we observed the influence of the doping of Sn4+ on the ZnO nanorods. At last, we fabricated the LED which used ZnO and ZnO:Sn nanorods as n-type layer.
In this study, the Sn doped ZnO nanowires were successfully fabricated by electrodeposition and do not require any additional annealing process. According to the result, the hydrogen peroxide concentration is fixed at 2.45 mM, the change in voltage from the -0.2 ~ -1.40 V, the scanning electron microscope (SEM) shows that the surface structure consists of tetragonal nanorods into a polycrystalline thin film, and-1.25V results for the hexagonal nanorods, the average column diameter of about 120 nm, but not all the nanorods grow along the c axis, by changing the concentration of hydrogen peroxide that, when the hydrogen peroxide concentration of 8.00 mM of the nanorods is the best, column diameter of about 220 nm. By the grazing angle X-ray diffraction analyzer (GIXRD) results that, compared to pure zinc oxide nanorods, the (002) peak decreased and broadened by doping 2 at.% Sn, reducing the crystalline. The Sn-doped ZnO film displays the energy band gap a little red-shift as compared to pure ZnO film by photoluminescence results. the X-ray photoelectron spectroscopy (XPS) analysis of the Zn-O bonding (binding energy of 1021.9 eV), Sn-O bond was 486.7 eV, that the number of tin valence 4 +, and by the composition analysis of zinc and oxygen ratio of about 1:1, doped tin about 2 at%. By the etch-depth analysis that, with the hydrogen peroxide concentration from 2.45 mM to 8.00 mM, 150 nm film thickness increased by 250 nm. By cathodic electrochemical method on 99.9% pure copper substrate surface to growth of p-type cuprous oxide film, the experimental results showed that when the deposition temperature is 35 ℃, the film has a high degree of preferred orientation (111), and the film thickness of about 4.5 μm, resistivity of about 1.35 Ω-cm. The cuprous thiocyanate films by electrodeposition of -0.90 V, this film has a p-type semiconductor characteristic by ultraviolet photoelectron spectroscopy (UPS) and energy dispersive x-ray analysis (EDX) analysis.
According to the I-V result, the Cu2O/ZnO-based diodes with large leakage current density, it is difficult to speculate oxide combined with oxides, resulting in interface voids, defects making poor diode characteristics. The ZnO-based/CuSCN diodes with small leakage current density and all have good diode characteristics, because oxides and organic compounds easier to combine. If we as a buffer layer of ZnO, the formation of ZnO / Sn-doped ZnO / CuSCN of the heterojunction, we can see the whole of the current density increased, and when the voltage reaches 8.00 V, the current density to achieve 3.5 mA / cm2.
| en_US |