Study On Luminescence Characteristics Of Semiconductor Materials Enhanced By Plasma Exciton On Metal Surface

In recent years,metal local surface plasmon resonance?LSPR?has been proved to be an effective method to improve semiconductor luminescent materials.When the energy of the exciton/photon in the semiconductor is similar to the vibrational energy of the metal local surface electron,the energy will be coupled with the local surface plasma?LSP?exciton and radiate into the free space.In this paper,the photoluminescence?PL?enhancement of semiconductor materials modified by metal particles is studied as follows:?1?FDTD is used to simulate the local field enhancement effect of metal with different shapes.The results show that the Purcell enhancement factor of ellipsoidal nanoparticles is nearly 3.5 times higher than that of cubic,cylindrical and triangular prisms.In addition,the effects of long-axis L,short-axis R,refractive index n and light source distance on the enhancement factors of ellipsoidal,double-spherical and double-core-shell spherical nanoparticles are simulated.Different degrees of optical field enhancement and tunable resonance wavelength are achieved.?2?The LSPR coupling effect of Au nanoparticles is based on theory and experiment,respectively.The near-field luminescence enhancement of GaAs thin films is realized.The absorption spectra and electric field distribution of Au nanoparticles are calculated theoretically,and the relationship between resonance coupling frequency and the size of gold particles was clarified.On this basis,Au particles of different sizes are prepared on the surface of GaAs films by controlling the magnetron sputtering time,and the PL enhancement was achieved nearly 10 times.?3?The LSPR coupling effect of metal nanoparticles is based on theory and experiment,respectively.The near-field luminescence enhancement of ZnO nanowires films is realized.The optical model of the ZnO micro-cavity is constructed by the theory,and the six surfaces of the micro-cavity are decorated by using the Ag particles,the local light field enhancement is realized,and the light field limiting efficiency is improved by6.72 percent.On this basis,the surface of the ZnO nanowire is decorated with the prepared Au and Ag nano-sol,the luminescence enhancement of the ultraviolet intrinsic compound and the inhibition effect of the visible defect luminescence are realized respectively.?4?CuGaO₂ nanorods are synthesized by hydrothermal synthesis and CGO nanorods/ZnO nanowires heterojunction are prepared successfully.The PL method is tested to uv light at 392.32 nm,and compared with the PL spectra of pure ZnO,the UV peak shows a red shift,and the spectrum spread nearly 2.5 times.In addition,the sub-band gap absorption effect caused by the built in field between the p-n junction is also found.