Enhanced Electroluminescence From Sn/Er Co-Doped SiO 2 Thin Film by Controlling Sn Content

Sn/Er co-doped SiO2 (SiO2-Sn-Er2Si2O7) thin-film based light-emitting diodes (LEDs) have been successfully fabricated by using the sol-gel method, which show an excellent Er3+ electroluminescence (EL) at 1.54 $\mu \text{m}$ . Under forward bias, the electroluminescence ranges from visible to near-infrared region has been observed. The EL intensity is enhanced by ~45 times at 1.54 $\mu \text{m}$ for device with Sn content of 70 mol% compared with the reference device with 50 mol% Sn content. The significant enhancement in EL can be attributed to improved electrical conductivity of Sn/Er co-doped SiO2 thin films and the better crystallization of erbium silicate nanocrystals. Moreover, the onset voltages of LEDs show an obvious reduction by increasing Sn contents and the lowest onset voltage is about ~12.7 V when the Sn proportion is 70 mol%. Our present work shows a new method to fabricate silicon-based LEDs and a promising potential to boost silicon-based light source towards practical application.