Fluorine‐Enhanced Room Temperature Luminescence of Er‐Doped Crystalline Silicon

The silicon‐based light‐emitting devices are the bottleneck of fully integrated silicon photonics. Doping silicon with erbium (often along with oxygen) is an attractive approach to turn silicon into a luminescent material, which has been explored for decades. One of the main challenges is the strong thermal quenching effect that results in weak photoluminescence (PL) efficiency. Herein, it is shown that the co‐doping of fluorine with erbium ions can significantly suppress the thermal quenching effect and Auger recombination, resulting in a three‐order‐of‐magnitude increase in PL compared to Er/O‐doped crystalline silicon. As a result, relatively strong PL is observed from fluorine‐doped silicon at room temperature.