Light emission from nanoscale silicon: the king of microelectronics advancing toward optoelectronic integrated circuits

The need for silicon-based optoelectronic components that can be integrated into microelectronic technology has stimulated a significant development effort. Photodetectors, waveguides, wavelength demultiplexers and modulators have all been fabricated in silicon-based technology. The capability of fabricating light-emitting devices (LEDs) in silicon-based technology would greatly expand the use of silicon as an optoelectronic material. Applications where silicon-based light emitters could be utilized include data transceivers for local area network communication, optical interconnects for high speed system integration, and low-cost high-resolution displays to name a few. This work presents an overview on LEDs that are based on nanoscale silicon. There are a number of different methods used to prepare crystalline silicon structures in the nanometer size regime, perhaps the most well-known being porous silicon formation via electrochemical anodization of crystalline silicon. Alternative methods of preparation include silicon nanopillar formation using lithographic and reactive ion etching techniques, as well as physical and chemical deposition techniques. Details of the material preparation, device design, and electroluminescence response from various research groups are presented.