Research On The Influence Of Metallic Surface Plasmon On The Emitting Property Of GaAs

Recently, the study on surface plasmon resonance has become a heated international topic. On surface plasmon enhanced spectral aspect, there are many reports that surface plasmon can greatly enhance the photoluminescence spectra of quantum dots, nanowires and quantum wells and other low-dimensional materials, so it is significant to grasp the interaction of surface plasmon with semiconductor materials. Consequently, this paper mainly chooses to research the near infrared photoluminescence(PL) enhancement mechanism of GaAs substrates covered by Au nanostructures which have significant local surface plasmon resonance(LSPR) effect. The primary content of the paper is as follows:First and foremost, we employed micro-nano photonics software FDTD(Finite-Difference Time-Domain) Solutions to simulate the extinction spectra and local electrical field intensity distribution of various Au nanostructures placed on the top of GaAs substrates. According to the above comprehensive simulations, we could draw the conclusion that when the LSPR wavelength of Au nanostructure matches the wavelength of incident light, the local electrical field intensity of Au nanostructure is about 2-3 orders of magnitude higher than that of incident light.Then, the research of LSPR effect of gold nanostructures on the near infrared PL of GaAs substrates was conducted in experiment. We used physical and chemical methods to produce Au nanostructures on GaAs substrates. The measured photoluminescence spectra and absorption spectra together demonstrated that the PL intensity of samples enhanced when LSPR wavelength of Au nanoparticles matched the incident wavelength.To sum up, our work reveals the close relationship between the enhanced local electrical field intensity of Au nanostructures and the increased PL intensity of GaAs substrates covered by Au nanostructures.