Photoluminescence characteristics of Er doped Ge nanocrystals embedded in alumina matrix

Abstract Er3+ doped Ge nanocrystals embedded in high-k Al2O3 matrix were prepared by pulsed laser ablation method. X-ray spectra and transmission electron micrographs have confirmed the formation of Ge nanocrystals and the increase in crystallite size with increasing annealing temperature from 750 °C to 950 °C. An enhanced photoluminescence intensity at 1.54 μm is attained by optimizing the Er concentration. Temperature dependent photoluminescence from samples annealed at different temperatures has shown the existence of thermally activated energy transfer process between Er3+ and Ge nanocrystals.