A multi-wavelength light-emitting semiconductor device and a method of fabricating the same are disclosed. The semiconductor device includes a substrate, a first reflector on the substrate, a light emission layer on the first reflector, second reflectors on corresponding active regions; and apertures on corresponding active regions. The light emission layer includes active regions. Each of the active regions includes a primary emission wavelength different from each other.

Provided is a vertical cavity surface emitting laser diode (VCSEL) with low compressive strain DBR layer, including a GaAs substrate, a lower DBR layer, a lower spacer layer, an active region, an upper spacer layer and an upper DBR layer. The lower or the upper DBR layer includes multiple low refractive index layers and multiple high refractive index layers. The lower DBR layer, the lower spacer layer, the upper spacer layer or the upper DBR layer contains Al.sub.xGa.sub.1-xAs.sub.1-yP.sub.y, where the lattice constant of Al.sub.xGa.sub.1-xAs.sub.1-yP.sub.y is greater than that of the GaAs substrate. This can moderately reduce excessive compressive strain due to lattice mismatch or avoid tensile strain during the epitaxial growth, thereby reducing the chance of deformation and bowing of the VCSEL epitaxial wafer or cracking during manufacturing. Additionally, the VCSEL epitaxial layer can be prevented from generating excessive compressive strain or tensile strain during the epitaxial growth.

Provided is a vertical cavity surface emitting laser diode (VCSEL) with low compressive strain DBR layer, including a GaAs substrate, a lower DBR layer, a lower spacer layer, an active region, an upper spacer layer and an upper DBR layer. The lower or the upper DBR layer includes multiple low refractive index layers and multiple high refractive index layers. The lower DBR layer, the lower spacer layer, the upper spacer layer or the upper DBR layer contains Al.sub.xGa.sub.1-xAs.sub.1-yP.sub.y, where the lattice constant of Al.sub.xGa.sub.1-xAs.sub.1-yP.sub.y is greater than that of the GaAs substrate. This can moderately reduce excessive compressive strain due to lattice mismatch or avoid tensile strain during the epitaxial growth, thereby reducing the chance of deformation and bowing of the VCSEL epitaxial wafer or cracking during manufacturing. Additionally, the VCSEL epitaxial layer can be prevented from generating excessive compressive strain or tensile strain during the epitaxial growth.

An optoelectronic device including a crystalline semiconductor layer based on GeSn and including a pin junction. This formed semiconductor layer includes a base portion; a single-crystal intermediate portion having an average value x.sub.pi1 of proportion of tin less than x.sub.ps1, thus forming a barrier region against charge carriers flowing in an upper portion; and the single-crystal upper portion including a homogeneous medium with a proportion of tin x.sub.ps1, and vertical structures having an average value x.sub.ps2 of proportion of tin greater than x.sub.ps1, thus forming regions for emitting or for receiving infrared radiation.

A semiconductor device includes a semiconductor layer formed of a III-V group semiconductor crystal containing As as a primary component of a V group. A V group element other than As has been introduced at a concentration of 0.02 to 5% into a V group site of the III-V group semiconductor crystal in the semiconductor layer.