HexSeed raises £600k to turn captured CO2 into semiconductor diamond coatings
The UK startup is developing a low-temperature process to improve heat management in data centres using synthetic diamonds derived from carbon emissions.
UK-based HexSeed Technology has secured more than £600,000 in early-stage funding to develop a process that converts captured carbon dioxide into synthetic diamond coatings for semiconductor devices. The investment aims to solve critical overheating issues in high-power electronics used in modern data centres.
The funding round was led by Carbon13, with additional participation from Vento Ventures and the Net Zero Technology Centre. According to the company, this capital injection also unlocks a Partnership Grant from Innovate UK. HexSeed is currently collaborating with researchers at the University of Bristol, including professors Martin Kuball and Paul May, to refine a low-temperature microwave plasma process. This technique allows the company to apply ultra-thin synthetic diamond coatings specifically to gallium nitride (GaN) power devices.
The Thermal Bottleneck
As the expansion of cloud computing and artificial intelligence accelerates, data centres are facing an unprecedented surge in electricity demand. A primary technical hurdle is heat management; while gallium nitride transistors are more efficient than traditional silicon, their high power density generates intense heat that is difficult to dissipate.
Diamond is recognized as an ideal thermal conductor, but traditional diamond growth methods require extreme temperatures that would destroy finished semiconductor hardware. HexSeed's low-temperature approach seeks to bypass this limitation, allowing the thermal benefits of diamond to be integrated into existing device architectures without damaging the underlying components.
Industrial and Environmental Impact
This technology addresses a critical bottleneck in infrastructure efficiency. By enabling superior heat dissipation, the coatings can reduce the energy wasted during power conversion. Mark Tandy, co-founder of HexSeed, noted that data centres are on track to consume a significant share of the UK grid capacity within the decade, with a large portion of that energy currently lost as heat.
Beyond hardware performance, the process integrates carbon capture and utilisation (CCU). By transforming CO2—a waste product and primary greenhouse gas—into a high-value industrial material, the technology aligns semiconductor manufacturing with broader net-zero environmental goals.
Next Steps
HexSeed will now focus on scaling its microwave plasma process and further validating the performance of its GaN-diamond coatings in real-world data centre environments. The company's success depends on whether the low-temperature coatings can maintain the thermal conductivity of diamond while remaining commercially viable for mass semiconductor production.