The recent development of optically pumped lasers made from Si-congruent GeSn alloys have strengthened the efforts to fabricate a monolithically integratable light source. Such fully Si-compatible solution may allow merging of state-of-the-art electronics with photonic components on the same chip for on-chip optical interconnects. To advance this prospering field, we investigated the epitaxy of different GeSn/SiGeSn heterostructures, based on GeSn active layers. Double heterostructures allow confinement of carriers in GeSn, though with the deleterious presence of misfit dislocations in the rather thick active regions. This can be overcome, however, in multi quantum well (MQW) structures. Microdisk resonators made from different heterostructures were fabricated, indicating enhanced properties of MQW layers. Epitaxy of in-situ doped p-i-n heterostructure diodes shows paths towards electrical carrier injection into GeSn optoelectronic devices.