Highly efficient electroluminescence from SnO₂ nanocrystals and Er³⁺ co-doped silica thin film via introducing Ca²⁺

Efficient and stable near-infrared silicon-based light source is a challenge for future optoelectronic integration and interconnection. In this paper, alkaline earth metal Ca 2+ doped SiO 2 -SnO 2 : Er 3+ films were prepared by sol-gel method. The oxygen vacancies introduced by the doped Ca 2+ significantly increase the near-infrared luminescence intensity of Er 3+ ions. It was found that the doping concentration of Sn precursors not only modulate the crystallinity of SnO 2 nanocrystals but also enhance the luminescence performance of Er 3+ ions. The stable electroluminescent devices based on SiO 2 -SnO 2 : Er 3+ /Ca 2+ films exhibit the power efficiency as high as 1.04×10 −2 with the external quantum efficiency exceeding 10%.