Dissertation > Excellent graduate degree dissertation topics show

Study on the Fabrication and Photoelectric Properties of the Heterojunction Based on ZnO

Author: NiManMan
Tutor: ZhangWeiFeng
School: Henan University
Course: Microelectronics and Solid State Electronics
Keywords: ZnO / NiO heterostructures N719/ZnO heterostructure L-MBE technology Surface photovoltage spectroscopy
CLC: TN304.21
Type: Master's thesis
Year: 2010
Downloads: 259
Quote: 0
Read: Download Dissertation

Abstract

Solar energy as an inexhaustible, inexhaustible green energy is one of the best ways to solve the energy crisis. In recent years, semiconductor - semiconductor heterojunction, a dye-sensitized semiconductor materials such hetero structure, easy to implement photoinduced charge separation is widely used to improve the conversion efficiency of the solar energy as well as the research and development of optoelectronic devices. ZnO is an important semiconductor optoelectronic materials, has a high transmittance in the visible region, and is a novel transparent semiconductor material. In addition, ZnO has many advantages of inexpensive, less toxic, and abundant sources become excellent material for preparation of optoelectronic devices, and a high level of development and application value. ZnO as the base with an inorganic p-type semiconductor material of NiO and organic dye N719 respectively configured hetero structure, and the photogenerated charge redistribution process by surface photovoltage test study, and its Application in the photoelectric conversion experiments and theoretical basis, mainly to do the following meaningful work: 1. paper, a purity of 99.99% of ZnO, NiO and 18.2 MΩ deionized water and dilute polyvinyl configuration binder solvent as raw materials produced ZnO, NiO, ceramic target. 1:10 mixed first by the ratio of polyvinyl alcohol and deionized water, The mixture was then placed in the heated waters, and magnetic stirring, the temperature was set at about 90oC, magnetic stirring until clear until; then was weighed with a balance the amount of ZnO, NiO powder into an agate mortar, an appropriate amount of polyvinyl alcohol binder was added dropwise, and polished until ZnO, NiO powder become small, uniform particle; Subsequently suppression of the abrasive powder is placed in a mold molding and unglued. Finally, after the degumming target on the the dedicated smart temperature control box furnace, sintered under an air atmosphere as ZnO, NiO ceramic target. Laser molecular beam epitaxy on a Si substrate and quartz substrate prepared good crystalline quality of ZnO thin films and NiO film, and the use of X-ray diffraction, Raman spectroscopy, photoluminescence spectroscopy, transmission spectra characterization methods to characterize the samples prepared. The results show that using laser technology to prepare a ZnO, the NiO crystal film preferably has a higher transmittance in the visible region, for later laid the foundation for the preparation and application of the device based on ZnO, NiO. 3. Better rectifying properties of ZnO / NiO heterojunction prepared FTO conductive glass substrate by laser molecular beam epitaxy. And X-ray diffraction, scanning electron microscopy, UV-visible absorption spectrum, photoluminescence spectroscopy, electrical testing, surface photovoltage spectroscopy means its characterization tests. The surface photovoltage test ZnO and NiO good level relative position, through the structure of ZnO / NiO heterojunction ZnO original peak (373 nm) the photovoltage response greatly enhanced. Further, 390-600 nm in the visible region can also lead to a new strong photoelectric response broadband, this is caused due to defects and NiO in the forbidden band sublevel. This has certain positive role in promoting the future development of the photovoltaic industry and solar energy conversion and utilization. 4 laser molecular beam epitaxy prepared well crystalline ZnO films on FTO conductive glass, and dye-sensitized ZnO films using N719 dye sensitization process by impregnation method. Through ZnO films the N719 sensitized before and after UV the comparison visible absorption spectroscopy, surface photovoltage spectroscopy, photoluminescence spectroscopy, Raman spectroscopy, and to explore the interaction between the organic dye and inorganic semiconductor materials. The results showed that N719 ZnO is sensitized can promote the separation of the photo-generated charge, and enhance the surface photovoltage, while suppressing the composite of the photo-generated charge, weakening the intensity of photoluminescence. Provide strong evidence for the transfer of the chemical adsorption and charge energy between the organic dyes and inorganic semiconductors. Practical applications in the photovoltaic industry for the promotion of dye-sensitized solar cells have certain positive significance.

Related Dissertations

CLC: > Industrial Technology > Radio electronics, telecommunications technology > Semiconductor technology > General issues > Material > Compound semiconductor > Oxide semiconductor
© 2012 www.DissertationTopic.Net Mobile