Diamond-based radiation detectors represent a significant advancement in radiation detection technology due to their unique material properties. Diamond, as a wide bandgap semiconductor, exhibits exceptional radiation hardness, low dark current, and fast response times, making it suitable for applications in high-radiation environments, medical imaging, and particle physics experiments. The intrinsic properties of diamond, combined with engineered defects and optimized electrode configurations, enable high-performance detection of alpha particles, X-rays, and neutrons.

One of the most critical advantages of diamond radiation detectors is their radiation hardness. Unlike silicon or other conventional semiconductor detectors, diamond does not suffer from significant lattice displacement damage when exposed to high-energy particles or ionizing radiation. The strong covalent bonds in diamond’s carbon lattice make it highly resistant to radiation-induced degradation, allowing it to maintain performance in environments where silicon detectors would rapidly degrade. Studies have shown that diamond detectors can withstand doses exceeding 10^16 protons/cm^2 without significant loss of charge collection efficiency, a threshold far beyond the tolerance of silicon-based devices.

Another key benefit is the low dark current exhibited by diamond detectors. The wide bandgap of 5.47 eV ensures minimal thermal generation of charge carriers at room temperature, reducing noise and improving signal-to-noise ratio. This property is particularly advantageous for applications requiring high sensitivity, such as low-dose X-ray imaging or rare-event particle detection. The absence of significant leakage currents allows diamond detectors to operate without active cooling, simplifying system design compared to cryogenically cooled alternatives like high-purity germanium detectors.

Diamond detectors also exhibit exceptionally fast response times, with charge carrier mobilities exceeding 2000 cm²/V·s for electrons and 1800 cm²/V·s for holes. The high carrier velocities enable sub-nanosecond temporal resolution, making diamond suitable for time-of-flight measurements in high-energy physics or ultrafast X-ray pulse detection. The combination of fast response and radiation hardness makes diamond detectors ideal for beam diagnostics in particle accelerators, where both speed and durability are critical.

Several types of diamond radiation detectors are employed depending on the target radiation. For alpha particle detection, single-crystal diamond detectors provide excellent energy resolution due to their low defect density and high charge collection efficiency. Polycrystalline diamond detectors, while less uniform, offer cost-effective alternatives for applications where moderate resolution is acceptable. X-ray detection leverages diamond’s high atomic number sensitivity and low absorption of low-energy X-rays, enabling efficient detection in medical and industrial imaging. Neutron detection is achieved through conversion layers containing boron or lithium, which interact with neutrons to produce secondary charged particles that diamond can detect.

Defects in diamond, particularly nitrogen-vacancy (NV) centers, play a significant role in detector performance. While NV centers are often studied for quantum applications, they also influence charge trapping and recombination dynamics in radiation detectors. Properly engineered defect concentrations can enhance charge collection efficiency by reducing trap-assisted recombination, but excessive defects can degrade performance by introducing trapping sites. Optimizing the defect density through controlled doping and annealing is crucial for achieving high detector efficiency.

Electrode materials and configurations significantly impact charge collection efficiency. Metals like gold, platinum, or titanium form stable contacts with diamond, minimizing interfacial resistance and charge injection. Transparent conductive oxides such as indium tin oxide (ITO) are used for applications requiring optical access, such as UV or soft X-ray detection. Interdigitated electrode designs improve charge collection in polycrystalline diamond by reducing carrier drift distances, mitigating the effects of grain boundaries.

Compared to silicon and cadmium telluride (CdTe) detectors, diamond offers distinct advantages and trade-offs. Silicon detectors provide excellent energy resolution and mature fabrication processes but suffer from radiation damage and require cooling for low-noise operation. CdTe detectors exhibit high stopping power for X-rays and gamma rays but are prone to polarization effects and degradation under prolonged irradiation. Diamond’s combination of radiation hardness, speed, and room-temperature operation makes it preferable for harsh environments, though its higher cost and lower atomic number limit its use in some energy ranges.

In summary, diamond-based radiation detectors excel in applications demanding durability, speed, and low noise. Their performance stems from diamond’s intrinsic material properties, optimized defect engineering, and advanced electrode designs. While challenges remain in cost reduction and large-area fabrication, ongoing research continues to expand their utility in medical, industrial, and scientific fields. The unique advantages of diamond ensure its growing role in next-generation radiation detection systems.