We review the technology of Ge 1−x Sn x -related group-IV semiconductor materials for developing Si-based nanoelectronics. Ge 1−x Sn x -related materials provide novel engineering of the crystal growth, strain structure, and energy band alignment for realising various applications not only in electronics, but also in optoelectronics. We introduce our recent achievements in the crystal growth of Ge 1−x Sn x -related material thin films and the studies of the electronic properties of thin films, metals/Ge 1−x Sn x , and insulators/Ge 1−x Sn x interfaces. We also review recent studies related to the crystal growth, energy band engineering, and device applications of Ge 1−x Sn x -related materials, as well as the reported performances of electronic devices using Ge 1−x Sn x related materials.