Silicon And Zinc Oxide Material Preparation And Optical Properties Of Study

We fabricated Si and ZnO nanostructured films by comprehensive utilization of the Porous Anodic Alumina membrane method and the Pulsed Laser Deposition method. We used many kinds of measurement devices to measure and analyze them and studied the photoluminescence characteristics of them.To research the photoluminescence mechanism of nanocrystalline silicon (Si) and to give some experimental backing for the fabrication of Si light emitting devices, we tried to make PAA by using a two-step anodization technique. We used Pulsed Laser Deposition (PLD) deposited a layer of Si on the PAA substrate through a two-step deposition procedure in vacuum .After that, we got a combined fihn of Si and PAA. Next, we put the combined film into acid solution to get rid of the PAA substrate. Then we got the Si fihn with Si nanowires scattered on it .We used Scanning Electronic Microscopy (SEM) and X-Ray Diffraction (XRD)to study the structure, morphology, crystalline phase and the composition of the film . The result showed that this Si structure is amorphous phase. The diameter of the nanowires is about 67.5 nm, the length is about 100nm, the number density is about 10¹¹/cm². The photoluminescence spectrum is a broad peak in visible light range with many small sharp peaks scattered on it which have their own fine structures. The wavelength intervals between the sharp peaks are different, but the energy intervals are equal. We analyzed the structure characteristics of the sample and used the Quantum Confinement Effect model and the Surface Photoluminescent Center model to explain the broad peaks of the photoluminescence spectrum. The possible reason of the sharp peaks was also discussed.ZnO is a good ultraviolet material that can be used widely in manufacturing photoelectronic devices.It has great value of researching and using. Porous alumina is a good kind of membranous substrate. PAA wereformed at different voltages in different acid solutions at 0°C. Then ZnO thin film was deposited on the porous alumina substrates in vacuum by Pulsed Laser Deposition. Several measuremental techniques, including Scanning Electronic Microscopy (SEM), X-Ray Diffraction (XRD) were used to analyze the morphology characteristics, crystalline phase and the composition of film. Its photoluminescence spectrums were also measured. The experimental results showed that the morphology and photoluminescence of the film grown on porous alumina of different pore diameters differ greatly. The photoluminescence peaks of the ZnO film grown on porous alumina made from sulphuric acid aqueous solution are at 394nm and 498nm. The photoluminescence peaks of the ZnO film grown on porous alumina made from oxalic acid aqueous solution are at 417nm and 466nm. The photoluminescence peaks of the ZnO film grown on porous alumina made from phosphoric acid aqueous solution are at 415nm, 495nm and 560nm .Because the film was fabricated in vacuum, it is rich in Zinc and the photoluminescence spectrum changed when it was exposed in air for some time. Under the guidance of solid state energy band theory, we analyzed the photoluminescence spectrums successfully.