Room Temperature Light Emitting Silicon Diodes Fabricated by Erbium Ion Implantation

In this work we report the fabrication and characteristics of light emitting erbium-doped Si diodes operating at room temperature (RT). These devices were prepared by multiple high energy Er implantation in the active region of a p(+)-n(+) Si diode. Oxygen or fluorine implantation in the Er-doped region was also performed in order to properly modify the Er3(+) chemical surrounding. Electroluminescence (EL) at 1.54 mu m and at RT has been observed under both forward and reverse bias conditions with the maximum intensity under reverse bias. The temperature dependence of the luminescence revealed that forward-bias EL decreases by about a factor of 30 on going from 100 K to 300 K. An identical temperature dependence is observed in photoluminescence (PL) suggesting that similar excitation mechanisms are responsible for PL and forward-bias EL. In contrast, reverse-bias EL presents a very weak temperature dependance, with a decrease by only a factor of 4 from 100 K to 300 K. These data are reported and possible excitation mechanisms are discussed.