It has been well known that the development of microelectronic and integrated circuit (IC), mainly based on silicon materials, have changed the way of our life dramatically and accelerated the development and innovation of new technologies. With the increase of integration density in ICs, the gate lengths of transistors are now scaled down to 7 nm, leading to fundamental challenges to keep up with the Moore’s law. One possible solution is to integrate optical circuits into the Si microelectronic platform to achieve high density electronic–photonic integration. This will combine the advantages of photons in energy-efficient and high bandwidth data transmission with those of electrons in high-speed data processing and high performance logics. It will thereby overcome the interconnect bottleneck and achieve high functionality as an extension to Moore’s law. In this opto– electro integration system, monolithic integrated group IV lasers are of great interest. However, the indirect bandgap nature of crystalline silicon limits its application in optoelectronics. In recent years, many researchers have tried to use the nano-sized Si structure or introduce group IV alloys, such as Ge, GeSn or other compounds, to address the light source issue and establish all Si-based electronic–photonic ICs.
In this special issue, we organized a focused discussion on the Si-based materials and devices. Our aim is to highlight remarkable contributions made by the leading scientists in this important research area and broad impacts of opto–electro integration. This special issue contains 9 review articles and 1 original research article. In this issue, we include the recent progress of SiGe, Ge and GeSn materials grown on Si, the light emitting of nanosized Si and its application, the graphene integrated Si photonic, the emerging technologies in Si active photonics and so on.
We sincerely hope that this special issue could provide a valuable reference and perspective for the research community working in this exciting field and inspire many more to enter this field. We would like to thank all the authors who have contributed high-quality peer-reviewed articles to this special issue. We are also grateful to the editorial and production staff of Journal of Semiconductors for their superb assistance.