This final report presents results obtained and progress made during September 20th, 2017 to March 19, 2019. This project is a part of the greater effort for the development of Si photonics that broadens the reach of Si material and technology beyond electronics. The focus of the project is the development of photonic devices based on the group-IV alloys, SiGeSn andor GeSn that can be integrated with the CMOS Si technology. In this project, we have made progress on three fronts. One is on the GeSn quantum structures that can benefit a range of photonic devices. The second is on light emitting diodes whose emission can be in-plane coupled into group-IV waveguides and subsequently be detected by GeSn based waveguide detectors. The third includes the demonstration of GeSn based vertical light emitters and optically pumped lasers. This report highlights the main achievements in these three areas.