On the origin of photoluminescence from silicon nanostructures: A new perspective

This review is aimed at describing recent developments in the field of silicon nanostructures, particularly those properties and phenomena that are connected with the room-temperature, photoluminescence (PL) from these nanostructures. Two classes of models are the most notable ones: the quantum confinement model that assigns the PL to quantum size effects in the nanocrystalline silicon core, and the surface chemistry model that assigns the PL to surface phenomena at the interface between the crystalline core and the host matrix that wrap the nanostructures. In recent years, with the improvement in growth techniques and methods to control dimensionality and shape, it has been suggested that none of the above models alone can explain the entire spectrum of optical phenomena in silicon nanostructures. Instead, a refined model that takes into accounts both phenomena should be considered. This review describes some of these recent developments in the field of silicon nanostructures, particularly those experiments and models that indicate the mutual role of quantum confinement and surface chemistry in shaping the optical properties of these nanostructures.