Light Emission in Periodically Microstructured Porous Silicon

It has been shown experimentally that the periodic microstructuring of the porosity in porous silicon (PS) resonant cavity light emitting devices (RCLEDs) radically improves their emission linewidth and beam quality1. However, an important issue not yet fully addressed is the precise role played by this periodic microstructuring, given that the luminescence is distributed throughout the whole structure and that the low porosity layers are highly absorbing. A greater understanding of this emission process is clearly essential for the optimisation of PS LEDs.