Using Localized Surface Plasmon Effects To Enhance The Luminescence Of Porous Silicon And Enhance Solar Cell Efficiency

Metals possess a large number of free electrons, making it different from the general dielectric medium. The coupling between free electrons in metals and electromagnetic waves forms Surface Plasmon Polariton (SPP) modes propagating along the metal surface. It is one of the most popular topics in nanoscience area to study the optical properties of noble metal nanoparticles as well as their applications in novel plasmonic effects. It has attracted much interests to enhance the photoluminescence of emitters and improve the efficiency of solar cells by using Localized Surface Plasmons (LSP) of noble nanoparticles.Porous silicon, a luminescent material that is compatible with traditional silicon-based techniques, may play an important role in future optical interconnection technology. Optical interconnection technology is a way to solve the electrical interconnection delay problem inside a chip or between chips. Light emitting device is one of the core devices in optical interconnection technology, and this device must be compatible with silicon, which is commonly used for mature fabrication and microelectronic techniques. Porous silicon has been one of the main candidates for silicon-based light emitting devices, therefore, great efforts have been devoted to increase the luminescence efficiency of porous silicon, which determines the realization of optical interconnection between chips. The photoluminescence of porous silicon can be enhanced by LSP effect introduced by gold nanoparticles. The emission from porous silicon can be coupled into the waveguide mode of gold Surface Plasmon, and it is further transferred into free space by scattering. Due to its high density of states of the surface Plasmon mode, the spontaneous emission rate of porous silicon is strongly increased by the coupling effect, and hence profoundly enhances its luminescence efficiency. Based on these effects, porous silicon has been one of the most promising materials for silicon-based high efficient light emitting devices, and provide the possibility of realizing the optoelectronic integration and optical interconnection applications.With the development of the human society, energy problem has become a growing difficulty worldwide. As good substitutions for non-renewable energy sources, solar energy and nuclear energy have been concerned the main energy sources in future. Now, development of silicon- and many inorganic metallic compound- based solar cells is the mainstream in this area. However, the conversion efficiency of silicon-based solar cells is still very low so far, due mainly to its low absorption efficiency. Starting from this point, gold nanoparticles are chosen, and strong enhancement of the absorption was observed. This is caused by the coupling of light field with the LSP of gold nanoparticles, which enhances the absorption efficiency, and hence increases the conversion efficiency of silicon-based solar cells.