A method for manufacturing an electronic-photonic device. Epitaxially depositing an n-doped III-V composite semiconductor alloy buffer layer on a crystalline surface of a substrate at a first temperature. Forming an active layer on the n-doped III-V epitaxial composite semiconductor alloy buffer layer at a second temperature, the active layer including a plurality of spheroid-shaped quantum dots. Depositing a p-doped III-V composite semiconductor alloy capping layer on the active layer at a third temperature. The second temperature is less than the first temperature and the third temperature. The active layer has a photoluminescence intensity emission peak in the telecommunication C-band.