The Influence Of Aluminium Nanoparticles On Photoluminescence Property Of Zinc Oxide Film

As one of the third generation semiconductor materials, ZnO attracts broad attention and has great application value on high performance semiconductor devices because of its very high forbidden band width and exciton binding energy. The near band emission of ZnO is located in UV zone, so it can be used to fabricate UV lasers and LEDs. During the growing process of ZnO, various impurities and lattice defects are introduced, leading to photoluminescence in visible light zone. How to improve UV emission efficiency and decrease emission of impurities and defect is an urgent problem need to be solved. As so far, some research work has shown that metal particles can increase near-band emission, however, the physical mechanism needs to be investigated more. This thesis investigates the influence of Al nanoparticles on ZnO photoluminescence property, and using FDTD methods researches surface plasmon resonance property of Al nanoparticles to explore the physical mechanism.Firstly, with magnetron sputtering techniques ZnO film is grown on silica substrate. The forbidden band is 3.23 eV and photoluminescence spectra shows obvious near-band emission wavelength.Then, Using the software FDTD Solutions researches the relationship between localized surface plasmon resonance and diameter of Al nanoparticles. The ZnO-film/Alnanoparticles structure is fabricated. Measuring ZnO-film/Al-nanoparticles structure’s photoluminescence spectrum demonstrates that the near-band emission is enhanced.At last, this thesis discusses the physical mechanisms—charge transfer theory and excitons-SPR coupling theory, behind the near-band emission enhancement of ZnO film. Growing Al₂O₃ film between ZnO film and Al nanoparticles, the charge transfer can be forbidden. And then researching the structure’s photoluminescence property can verify the charge transfer theory. The result shows that the enhancement still exists without charge transfer. Combining numerical simulation and experiment, the thesis discusses the excitons-SPR coupling theory further and proposes a possible and complete coupling process, which can be positive to theory research and devices fabrication.