Diamond has emerged as a promising material for high-power electronic devices due to its exceptional physical properties, which surpass those of conventional semiconductors like silicon (Si), silicon carbide (SiC), and gallium nitride (GaN). Its ultra-wide bandgap of 5.5 eV, high breakdown electric field of 10 MV/cm, and unmatched thermal conductivity of 2000 W/m·K make it an ideal candidate for applications requiring high voltage, high frequency, and extreme thermal management. These attributes enable diamond-based devices to operate at higher power densities and temperatures than SiC or GaN, potentially revolutionizing power electronics.

The high breakdown field of diamond allows devices to sustain much higher voltages before experiencing electrical failure compared to SiC (3 MV/cm) and GaN (3.3 MV/cm). This property is critical for reducing conduction and switching losses in high-power applications. Additionally, diamond's thermal conductivity is an order of magnitude higher than SiC (490 W/m·K) and GaN (253 W/m·K), enabling efficient heat dissipation and improved reliability under high-power operation. These advantages suggest that diamond devices could outperform existing technologies in high-voltage switches, rectifiers, and power amplifiers.

Theoretical designs for diamond-based field-effect transistors (FETs) leverage its high carrier mobility and breakdown strength. Hydrogen-terminated diamond FETs exhibit a two-dimensional hole gas with high sheet carrier density, enabling high current densities. Simulations predict that diamond FETs could achieve breakdown voltages exceeding 10 kV with specific on-resistances below 0.1 mΩ·cm², outperforming SiC and GaN devices. However, challenges such as high contact resistance on p-type diamond and the absence of n-type doping with sufficient conductivity limit practical implementations. Recent progress in ohmic contacts using carbide-forming metals like titanium and molybdenum has reduced contact resistances to the 10⁻⁵ Ω·cm² range, but further optimization is needed.

Schottky diodes based on diamond offer low reverse leakage currents and high forward current densities due to the material's wide bandgap. Theoretical models suggest that diamond Schottky diodes could achieve blocking voltages above 5 kV with minimal leakage, making them suitable for high-efficiency power conversion. Experimental prototypes have demonstrated breakdown voltages exceeding 2 kV, but challenges remain in achieving uniform Schottky barriers and minimizing defects at the metal-diamond interface. The lack of large-area, high-quality single-crystal diamond substrates further complicates commercialization.

Thyristors utilizing diamond could enable ultra-high-voltage switching with minimal losses. Simulations indicate that diamond thyristors could handle voltages beyond 20 kV, far exceeding the capabilities of Si or SiC devices. However, the absence of reliable bipolar doping in diamond poses a significant hurdle. While boron doping provides p-type conductivity, the lack of a practical n-type dopant with shallow activation energy prevents the realization of diamond-based bipolar devices like thyristors or PIN diodes. Research into alternative doping techniques, such as delta doping or hyperdoping, is ongoing but has yet to yield viable solutions.

Material challenges remain a critical barrier to the widespread adoption of diamond in power electronics. The limited availability of large, high-quality single-crystal diamond substrates increases costs and restricts device scalability. Chemical vapor deposition (CVD) techniques have improved, producing wafers up to 1 inch in diameter, but defects and impurities still affect device performance. Heteroepitaxial growth on iridium or silicon substrates offers a potential workaround, but the resulting films often contain high dislocation densities, degrading electronic properties.

Contact resistance is another major challenge, particularly for p-type diamond. While hydrogen-terminated surfaces enable surface conduction, achieving low-resistance ohmic contacts requires precise interface engineering. Recent advances in metallization schemes, such as tungsten carbide interlayers, have reduced contact resistances, but further improvements are necessary to compete with mature SiC and GaN technologies.

Simulation studies have demonstrated the theoretical superiority of diamond devices in high-voltage operation. Finite-element modeling predicts that diamond FETs could achieve specific on-resistances below 0.05 mΩ·cm² at 10 kV, significantly lower than SiC (0.2 mΩ·cm²) and GaN (0.1 mΩ·cm²). These simulations highlight diamond's potential for reducing conduction losses in high-power converters. Experimental results, though limited by material quality, have shown promising progress. Diamond MOSFETs have demonstrated blocking voltages up to 1.7 kV, while Schottky diodes have achieved 2.5 kV operation with low leakage currents. However, these results remain below theoretical predictions due to defects and non-ideal contacts.

Thermal management simulations further underscore diamond's advantages. Electro-thermal models indicate that diamond devices can operate at power densities exceeding 10 kW/cm² without exceeding 200°C junction temperatures, whereas SiC and GaN devices would require aggressive cooling solutions under similar conditions. Experimental thermal resistance measurements confirm diamond's superior heat spreading capability, with device temperatures rising only marginally under high power dissipation.

Despite these advantages, diamond power electronics face significant hurdles before commercialization. The high cost of single-crystal substrates, immature doping techniques, and challenges in device fabrication must be addressed. Advances in CVD growth, defect reduction, and contact engineering could accelerate progress. If these obstacles are overcome, diamond-based devices could enable next-generation power systems with unprecedented efficiency and power density, particularly in electric vehicles, renewable energy conversion, and grid infrastructure.

In summary, diamond's exceptional material properties position it as a leading candidate for future high-power electronic devices. Its high breakdown field and thermal conductivity offer significant advantages over SiC and GaN, but material and fabrication challenges must be resolved to unlock its full potential. Continued research into substrate growth, doping, and contact technologies will be critical for realizing practical diamond-based power devices.