Photoelectric Studies On The Semiconductor Films By Plused Laser Deposition

Oxide semiconductor materials possess the advantages of low cost, simple andcompatible industrial devices, realization of flexible devices. They can be applied inthe development of light-emitting diodes, flat panel display, and thin film transistors.Chalcogenide glasses have received considerable attention in the last few yearsbecause of both their good transparency in the mid-infrared and their high linear andnonlinear refractive indices. They can be applied in the development of infrared bandoptical waveguide devices and all-optical processing of telecommunications signals.The research work in this thesis intends to understand the mechanisms of the chargegeneration, transport, and provides guidance in oxide semiconductor thin film,providing effective reference for the development of high-efficiency oxideoptoelectronic devices. We focus on the investigation of different semiconductormaterials and devices, optical physics and photonics process characteristics of themain line, basing on micro-and nano materials science. The following three sectionsare included in this thesis:1. Theoretical analysis and experimental prepared of P-type and roomtemperature magnetic properties for diluted magnetic semiconductorcobalt-doped ZnO film and the PN junction. Through the development andresearch status of diluted magnetic semiconductors historical research on theexperimental use of pulsed laser deposition method, successfully preparedcobalt-doped zinc oxide target and micro-nano film. Through the optical andstructural properties of materials, electromagnetic testing, found that zinc oxide atroom temperature for two different types of magnetic and conductive thin film dopedwith cobalt. The relationship between material properties and preparation methodsand processes, the theoretical derivation of the lamellar microstructure of cobaltclusters in ZnO thin films. Confirmed experimental and theoretical, P-type roomtemperature magnetic cobalt-doped zinc oxide thin films of cobalt clusters conjectureis correct.2. Optical properties of amorphous IGZO semiconductor thin film transistor andthe theoretical analysis and simulation of device optimization. Using solid-phasesintering method and pulsed laser deposition technique, the InGaZnO (IGZO) ceramictargets and films were prepared under annealing process and linear variation ofcomponents ratio. We analyzed the dependencies of process parameters and physicalcharacteristics for the IGZO targets and films. Found that the higher the mixing ratioof the indium oxide selected appropriate program allows a higher mobility of the film,while maintaining its amorphous character, and its physical mechanism and describes the causes. And a higher proportion of indium oxide ratio on the basis of in situannealing process, looking to a higher mobility index, its analytical testing foundmixed phase structure and explain its microscopic structure and mechanism. The useof home-made high-quality film properties, a variety of IGZO semiconductor devices(such as Schottky diodes, flexible thin-film transistors, etc.) were successfullyprepared.3. The dependence of photosensitivity on composition for thin films ofGexAsySe1-x-ychalcogenide glasses. We prepared twelve samples of Ge-As-Se thinfilms with different chemical compositions and investigated the stability of the filmswhen exposed to light at their band edge. While measurements of the bandgap of thefilms with increasing exposure revealed photo-bleaching or (exceptionallyphoto-darkening) behavior, we found that some of the films with MCN around2.45-2.50were photo-stable to within the accuracy of our measurements even whenexposed with high fluences of60kJ/cm2. Raman spectra showed that films within thisrange of MCN showed no changes as a result of exposure whereas clear changescould be observed for films with measurable photosensitivity. Overall we find thatindependent measurements of film-forming properties, of the thermal parameters andphotosensitivity overwhelmingly suggest that the most stable glasses lie in a smallregion of MCN space between2.45and2.5. Such compositions most likely signifythe existence of the IP previously identified from temperature-modulated differentialscanning calorimetry. What the results unequivocally show is however, that glasses inboth the floppy and stressed-rigid phases at low and high MCN respectively haveinferior properties when considered for applications in photonics where stability is ofimportance. These results additionally confirm that parameter such as the glasstransition temperature, which increases monotonically with MCN, is not a predictor ofglass stability.