Being the key component of the semiconductor industry, silicon in form of nanowire has recovered increased attention. Semiconductors, especially silicon, form the basis of modern electronics, but, although silicon is the dominant semiconductor, light emitting devices are today based on semiconductors, which supports fast radiative recombination. Regrettably, silicon is owing to its indirect band gap an especially poorly emitter of light and is a kind of semiconductor, which converts extra energy into heat. The problem is that silicon doesn't emit light and the materials that do it, are not absolutely the best materials for production electronic devices and are not compatible with silicon-based electronic devices. Thus integrating electronic and photonic circuits is a challenge. In an indirect band gap material like silicon, when the electron achieves the conduction band minimum, the valence band maximum does not match with corresponding moment. That is the main difference with a direct-band gap material. This prevents radiative recombination of the electron-hole pair from the conduction band minimum to the valence band maximum as both energy and momentum must be obtained. Semiconductor nanowires are at the top of nanotechnology research. They combine the material properties of semiconductors with nanoscale dimensions. With silicon determined as the material of option for the electronics industry, improving its optical properties would make consumer-level usage of the technology more feasible. The aim of this work was thus to enhance light emission of silicon combining nanowires with plasmonics. Using silicon nanowires and metallic nanocavities leads to increased interaction between light and matter. This interaction arises when light is confined to dimensions below the size of its wavelength. This thesis examines how the integration of plasmonic cavities and semiconductor nanowires leads to essential increase of efficient visible light emission that may be tuned as a function of cavity geometry and the used materials. The purpose is the verification and optimization of a method in order to achieve the highest possible photoluminescence. To generate light emission from hot carriers, a plasmonic nanocavity on individual silicon nanowires was fabricated by depositing an oxide interlayer followed by the formation of a silver cavity to support surface plasmon polariton modes. Once the electron is excited to the conduction band in silicon, characteristically by a phonon assisted process, its behavior is similar to that of an excited charge carrier in a semiconductor with a direct band gap. The excited electron will rapidly rest up to the conduction band minimum via phonon scattering events. To understand the cooperation of silicon phonon and nanocavity plasmon resonances leading to efficient light emission, photoluminescence (PL) measurements were carried out. The result of this experiment was broadband luminescence from silicon nanowires. The experimental observations can also be explained by the Purcell effect. Purcell effect describes that the rate of light emission from an electron-hole pair in a semiconductor is a function of the environs of that optical emitter. The use of optical cavities to enhance the spontaneous emission rate of excited atoms is discussed according to the Purcell theory. The focus of this work is to obtain spontaneous emission enhancement using plasmonic nanocavities. Additional, characteristics of surface plasmon polaritons (SPP) are described. Metals can confine the light in to deep-subwavelength dimensions. When light is invading on the surface of a metal the surface electrons and photon may form a strongly coupled system, known as the surface plasmon polariton. The surface electrons embed the light to the surface of the metal. This results in an electromagnetic mode that may propagate on the surface of the metal. Finally silicon nanowires coupled with plasmon nanocavities were integrated in an electrostatic actuated straining device (EASD) and the changes in PL spectra depending on strain were investigated. Silicon strain engineering is an essential process innovation in semiconductor fabrication. The piezoresistive effect is a change in the resistance of a semiconductor or metal when a strain is applied. The piezoresistivity of silicon is ten to twenty times higher than in metals. Silicon is therefore a promising alternative for strain gauges with high sensitivity. This knowledge made silicon a promising alternative for strain gauges with high sensitivity. On the other hand, nanowires exhibit a giant piezoresistivity and thus can be used to enhance the strain sensitive sensors. In this work it is attempted to combine this advantage of silicon nanowires with plasmonics and to observe the PL effects in nanowires as a function of strain.