The progressive miniaturization of materials and devices in the 21st century has enabled important discoveries and access to a wide range of phenomena of fundamental and applied interest. But future progress and innovative solutions to global challenges require a shift towards transformative material systems and integration technologies. Here we propose to establish at the University of Nottingham a facility (EPI2SEM) for the EPItaxial growth and in-situ analysis of a new generation of 2-dimensional SEMiconductors based on metal chalcogenides. Their unique electronic properties (tuneable band structure, IR-VIS-UV broad optical absorption, electron correlations, high electron mobility, etc.) and versatility for a wide range of applications (digital flexible electronics, optoelectronics, quantum technologies, energy, etc.) have attracted a surge of interest worldwide. However, for these new materials to meet academia and industry needs, several challenges must be addressed, including their controlled scalable growth, investigation by advanced techniques, and integration in complex device architectures. EPI2SEM will provide the UK community with a unique capability for the development of semiconductors grown with atomic layer precision in a clean ultra high vacuum system with fully-characterised electronic, chemical and morphological properties for advances across several research disciplines. EPI2SEM will enable the transformative miniaturization and functionalization of semiconductors for advances in condensed matter (quantum materials), manufacturing (new processes and designs), quantum technologies (security, sensing, communication), nanotechnologies (low-energy consumption, diversification, integration), surface physics (sensing, catalysis, energy conversion). Progress in these areas is key to the health of several research disciplines (engineering, medicine, chemistry, biology, etc.) contributing towards prosperity outcomes. The future competitiveness of the UK economy relies on innovation in science; ability to respond timely to global changes/challenges through innovation in infrastructure; the availability of highly-skilled and trained scientists and technologists; and flexibility to exploit novel technologies and materials to deliver better quality of life. This proposal has the potential to deliver innovation across these areas, addressing several challenges facing society. In particular, EPI2SEM will contribute to address the EPSRC priority of "21st Century Materials". In 2013, David Willetts announced the Eight Great Technologies that will propel the UK to future growth. This includes "Advanced Materials and Nanotechnology" that led to the establishment of the Henry Royce Institute (NGI) and the National Graphene Institute (NGI). One of the research pillars of the HRI/NGI is "2D Materials", but methods for their manufacturing need to be developed. The new equipment will set out the key steps needed to reach a long-term vision and benefit strategically important research areas, as set out in the 2018 government industrial strategy White paper.