Efficient Er/O Doped Silicon Light-Emitting Diodes at Communication Wavelength by Deep Cooling

TL;DR

This paper demonstrates that deep cooling after high-temperature annealing significantly enhances erbium-doped silicon LEDs' efficiency, achieving record room-temperature emission and promising integration into silicon photonics.

Contribution

It introduces a deep cooling process to suppress erbium aggregation, markedly improving silicon LED efficiency at communication wavelengths.

Findings

Achieved 14% light-emitting efficiency at room temperature.

Observed bright electroluminescence at 1.54 μm from silicon diodes.

Deep cooling increases efficiency by two orders of magnitude.

Abstract

A silicon light source at communication wavelength is the bottleneck for developing monolithically integrated silicon photonics. Doping silicon with erbium ions was believed to be one of the most promising approaches but suffers from the aggregation of erbium ions that are efficient non-radiative centers, formed during the standard rapid thermal treatment. Here, we apply a deep cooling process following the high-temperature annealing to suppress the aggregation of erbium ions by flushing with Helium gas cooled in liquid nitrogen. The resultant light emitting efficiency is increased to a record 14% at room temperature, two orders of magnitude higher than the sample treated by the standard rapid thermal annealing. The deep-cooling-processed Si samples were further made into light-emitting diodes. Bright electroluminescence with a spectral peak at 1.54 um from the silicon-based diodes was also observed at room temperature. With these results, it is promising to develop efficient silicon lasers at communication wavelength for the monolithically integrated silicon photonics.