Quantum confinement in rare-earth doped semiconductor systems

Rare-earth doped materials are widely deployed in optoelectronics and optical telecommunications technology, despite the difficulties associated with doping silicon with optically active rare-earth ions. Nanotechnology promises new classes of materials and devices that exploit the unique optical and electronic properties of low-dimensional structures; in particular, quantum confinement can modify the electronic structure of semiconductor hosts in such a way as to greatly increase the radiative efficiency of the rare-earth dopant. This article reviews some of the recent developments in the field and highlights possible future directions.