Optical and electrical properties of silicon rich oxide films for optical sensors

Silicon rich oxide (SRO) films have various applications as optoelectronic devices, especially as light emitters. Nowadays, the emission mechanisms in the SRO films are not completely understood, leading to a high potential field of research. The study of the SRO film's characteristics and its relation with the absorption and emission spectra would provide information on the mechanism of radiation. Moreover, the optical and electrical characteristics of the SRO films need to be understood in order to improve and propose novel devices. In this work the study of the optical and electrical properties of the SRO films is done. Photoluminescence, absorption spectra, AFM, refractive index and I–V characteristics in the SRO films were obtained and analyzed. The silicon excess and defects in the SRO films should have an important role in the photocurrent. We assume that a high responsivity to a visible light of the SRO/Si junction is achieved probably due to a combined effect of electron hole pairs in the silicon substrate and photo excited electrons in the SRO films.