The silicon based optical emitting materials are always the first candidate materials for the optoelectronic IC (OEIC) and its engineering applications

due to its low cost and the excellent compatibility with the advanced Si technology in microelectronics. However

the crystalline bulk silicon is an indirect electronic bandgap semiconductor with very poor light emission efficiency. It has been considered unsuitable for optoelectronic applications. A great challenge to experimenters and theorists is that how to make or design an efficient Si-based light emission material using an advanced technology and physics principles. In recent

several schemes

except porous silicon

have been suggested which include the silicon nanocrystals

c Si/O superlattices (SLs) and dislocation engineering. The light emission efficiency has been improved greatly in these Si-based systems. Based on the review of these new achievements

design a Si-based material with direct bandgap is considered a more direct solution. Because of the interface states in Si-based devices have a slow response rate in optical processes. Avoiding interface states are very important for the high speed optical devices and its applications. However

one does not know any critical rule for designing the newly Si-based materials with a direct band-gap until now. In this paper we suggest an empirical symmetry rule and design a series of Si-based superlattices. The computer simulations indicate that one of these superlattices

Se/Si

10

/Se/Si

10

/Se

is a semiconductor with a direct-gap character and its band-gap lie in the infrared range

perhaps

to be lie in the window of minimal absorption in current optical fibers. It is expected that the materials and its devices have the excellent abilities for light emission and other optical properties. In addition

this material is easily compatible with Si microelectronics technologies. Therefore

the material produced from computational design may be having potential applications in the field of the optoelectronics.