A study of luminescence from silicon-rich silica fabricated by plasma enhanced chemical vapour deposition

Silicon is the most studied electronic material known to man and dominates the electronics industry in its use as a semiconductors for nearly all integrated electronics. However, optoelectronics is almost entirely based on III-V materials. This technology is used because silicon is a very inefficient light source, whereas the III-V band structure can lend itself to efficient light emission by electron injection. However, due to the overwhelming dominance of silicon based electronics it is still a highly desirable goal to generate light efficiently from silicon based materials. Recently, studies have demonstrated that efficient visible luminescence can be obtained from certain novel forms of silicon. These materials include porous silicon, hydrogenated amorphous silicon, and silicon-rich silica (SiOx x<2). This study examines the visible luminescence from silicon-rich silica fabricated by plasma-enhanced chemical vapour deposition and draws the conclusion that the light emission from this material is associated with quantum confinement of silicon nanoclusters and defect luminescence. This study demonstrates that plasma enhanced chemical vapour deposition is a suitable technique for producing luminescent silicon-rich silica. Photoluminescence of SiOx is studied in detail; in addition, electroluminescence and rare-earth doping of silicon-rich silica is also addressed. (author)