Nanocluster Si sensitized Er luminescence: Excitation mechanisms and critical factors for population inversion

Abstract

Luminescence from Er3+ ions sensitized by nanocluster Si is investigated using finite-element, Monte-Carlo simulations. We find that we can reproduce and explain many conflicting results that have been reported using only a simple Forster-type interaction. In particular, we show that Er-Er energy migration plays a major role in Er3+ excitation such quantities such as excitation distance and sensitized fraction depend on optically active Er fraction and pumping power. Based on simulation results, we identify optically active fraction as the critical factor and suggest a multi-layered structure as being ideal for achieving population inversion. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4757001]