The underlying remarkable material properties of diamond offer the prospect for semiconductor devices with extraordinary potential in high power applications, as well as those requiring operation at high temperature and in high radiation environments. However, despite their tremendous potential, the progress in developing diamond high voltage devices has been severely impeded by challenges associated with the availability of good quality substrates, limitations in thick and high quality epilayer growth and advanced device processing technologies . Moreover, advances have been additionally hampered by the lack of shallow n-type dopant species. However, recent progress by the applicants in developing diamond technologies make these above listed challenges considerably reduced enabling further advances in pursuit of developing high power diamond electronics. In this context, the applicants' recent discovery of the highly novel steady state deep-depletion concept for diamond devices opens routes for further advancements in the field of diamond power devices; critically, deep-depletion devices remove the need for an n-type doping. Vertical Deep-Depletion (D2) Diamond MOSFETs and Trench MOS Schottky barrier diodes (TMBS) will be realised offering exceptional performance in terms of power handling capability, size, switching frequency and thermal-radiation resilience. Developing more energy-efficient high-power devices will lead to efficient power converters, key for the drive to more efficient power generation and distribution systems within the context of the low carbon economy. However, additionally, diamond devices proposed will be that these devices can tolerate extreme operational environments and offer enormous potential in key sectors such as automotive, aerospace, and nuclear industrial sectors.