Visible light emission from macroporous Si

Macroporous silicon structures have been fabricated by electrochemical etching. Such fabrication process is known to result in the presence of a thin microporous Si layer at the walls of the macropores and at the surface. Photoluminescence measurements conducted in plan-view and cross-section exhibit a wide emission peak around 650 nm which can be attributed to the microporous Si. The combination of a photonic crystal and a light emitter in one structure represents a potential for applications that has not been studied previously. We initiate this study by investigating the influence of the main fabrication parameters, namely the current density and the etchant solution, on the emission properties of the microporous Si layer.