Process for fabricating an optoelectronic device for emitting infrared light comprising a GeSn-based active layer

A process for fabricating an optoelectronic device for emitting infrared radiation, including:i) producing a first stack containing a light source, and a first bonding sublayer made from a metal of interest chosen from gold, titanium and copper,ii) producing a second stack containing a GeSn-based active layer obtained by epitaxy at an epitaxy temperature (Tepi), and a second bonding sublayer made from the metal of interest,iii) determining an assembly temperature (Tc) substantially between an ambient temperature (Tamb) and the epitaxy temperature (Tepi), such that a direct bonding energy per unit area of the metal of interest is higher than or equal to 0.5 J/m2; andiv) joining, by direct bonding, at the assembly temperature (Tc), the stacks.