Progress towards silicon optoelectronics using porous silicon technology

We briefly review the performance to date of a variety of porous Si-based discrete optoelectronic devices. Light emitting diodes, waveguides and photodetectors have now been demonstrated, together with a number of non-linear optical effects that could be exploited in electro-optic or all optical modulators. In each case comparison is made with bulk Si devices to identify where exploitation of porosity has already resulted in significant performance gains, or might do in the future. Dramatic progress has recently been made with regard to visible light emitting diodes and efficiencies are now > 104 × higher than those of bulk Si devices. Preliminary studies suggest that porous Si should also be developed for both passive and active waveguiding. Key problems that are still to be addressed with regard to applications are also identified.