Colloquium: Dr. Lyudmilla Goncharova, Western University

We live in an era of continuous transition from electronic to optoelectronic and optical devices. Silicon dominated microelectronic technologies, and now photonics offers great benefits in cost, performance and power consumption. Today, integration of Si photonics is challenged by compound semiconductors and Si microelectronics (complementary metal-oxide-semiconductor (CMOS) technologies), mostly due to the problems associated with making Si a sufficient light emitter, and thus realizing a laser. Light emission from Si and Ge quantum structures has been a focus of research due to the need to silicon-based light sources in optoelectronic and photonic applications. We compare Si QDs prepared in silicon oxide and silicon nitride and discuss their potentials for application in light emitting devices. There is a relationship between the preparation method of Si and Ge quantum structures, and the structural, electronic, and optical properties in terms of strength of quantum confinement (QC).[1] 

Si nanoclusters (Si-NCs) embedded in dielectric materials have been the subject of intense research due to their potential applications in optical and optoelectronic devices. A number of research studies have focused on Si-NCs made by implanting Si ions in SiO₂.  However, the mechanism by which Si-NCs luminescence is not fully understanding due to the difficulty in distinguishing between luminescence originating from defects in the SiO₂ matrix and Si-NCs. [2] Gaining an understanding of these processes would aid in the development of a Si- based light source, which is key to the development of high efficiency optical and optoelectronic devices. It is for these reasons that we have chosen to study the luminescence of Si implanted Al₂O₃ films. Al₂O₃ possesses a band gap energy that is adequate for charge carrier confinement and a high dielectric constant which makes it a promising candidate for charge storage devices. Using Al₂O₃allows for better interpretation of the luminescence spectra and its transparency makes it suitable of the fabrication of transparent devices.