Narrow Results

In this paper, addition of aluminum in zinc oxide is incorporated using low-temperature chemical synthesis route. Aluminum ions help in crystallization of zinc oxide nanoparticles. Characterization of the synthesized nanoparticles of zinc oxide has been done using Transmission electron microscope (TEM), and X-ray diffraction (XRD) analysis, Energy-resolved photoluminescence (PL) spectra and Time-resolved laser-induced photoluminescence (TRPL) at room temperature. Transmission electron microscopic observations and X-Ray diffraction studies indicate highly crystalline nature and particle size of the order of 20 nm in ZnO:Al. Time-resolved laser-induced photoluminescence measurements have been done using pulsed nitrogen laser as an excitation source, operated at wavelength 337.1 nm and having high peak output power of 1 MW. The results show that at higher concentrations of Al doping in host ZnO phosphor, emission intensity is more by several orders of magnitude and lifetime shortening indicates that these nanoparticles are more efficient as compared with lower concentrations of dopant.

ZnO:Al/p-Si heterojunction was fabricated by depositing a hexagonal nanocrystal ZnO:Al film on p-type Si substrate using a simple chemical bath deposition (CBD) method. The vertically aligned hexagonal ZnO:Al nanocrystals reduce the grain boundary scattering and provide good conductivity. The ZnO:Al/Si heterojunction shows obvious photocurrent under ultraviolet (UV) illumination. A high UV-to-visible rejection ratio of the ZnO:Al/Si heterojunction indicates that the hexagonal nanocrystal ZnO:Al film is a good material for fabricating UV photodetectors. Furthermore, the response speed of the photodetector based on ZnO:Al hexagonal nanocrystal film is faster than that of most previously reported photodetectors based on ZnO:Al nanorods. We infer it is because the ZnO:Al nanocrystals film has a smaller surface to volume ratio than the ZnO:Al nanorod array.