In this study, 2-inch single-crystal diamond (SCD) was fabricated via mosaic growth and laser stealth dicing. First, the growth behavior of 2 inch-scale diamond in an enclosed substrate holder was simulated, obtaining the spatial conditions conducive to continuous growth of large-area SCD. Subsequently, SCD wafers with dimensions of 50 × 25 mm2 and 48 × 48 mm2 were assembled through mosaic growth. Finally, the 48 × 48 mm2 SCD wafer was successfully and rapidly (approximately 40 min) detached by laser stealth dicing technology with a subsurface damage layer thickness of less than 100 micrometers.

Achieving efficient p-type conductivity is essential for advancing diamond-based high-power and high-frequency electronic devices. In this study, we employ first-principles calculation to evaluate Be as a p-type dopant in diamond and investigate the synergistic enhancement achieved through N-Be co-doping. The high-concentration Be doping can significantly reduce the acceptor ionization energy to 0.35 eV. More importantly, N-Be co-doping substantially reduces defect formation energies and acceptor ionization energies, N-4Be co-doped structure shows the reduced formation energy of 3.37 eV and acceptor ionization energy as low as 0.30 eV. These findings pave the way for the experimental realization of high-performance diamond-based electronic devices and suggest the potential for exploring donor–acceptor co-doping to achieve efficient p-type conductivity.

Nuclear battery is a potential energy generator because of its long lifetime, stable output performance, high energy density and environmental resistance. It converts the energy of high energy particles into electric energy. The main constituent parts of nuclear batteries are radioisotope and semiconductor energy converter. Diamond is ultra-wide band gap semiconductor with high carrier mobilities and high chemical inertness. More importantly, it is an excellent radiation resistance material. Therefore, diamond is an ideal material for the fabrication of nuclear batteries. This paper reviews the development status of diamond-based nuclear batteries. The alpha-voltaic, beta-voltaic and gamma-voltaic nuclear batteries based on diamond Schottky junction and p–n junction are illustrated in this review. In addition, an outlook on future research of diamond-based nuclear batteries is also provided.

Diamond and diamond-like carbon (DLC) films serve as cornerstone materials in surface engineering for tribology and corrosion protection. Diamond films, synthesized via chemical vapor deposition, offer exceptional hardness, thermal conductivity, and chemical inertness, yet face challenges in surface roughness, adhesion, and coating complex geometries. In contrast, DLC films composed of sp2/sp³ hybridized carbon—provide a tunable alternative that bridges diamond’s extreme properties with industrial applicability. This review systematically examines both materials, focusing on engineering design, deposition advances, and performance optimization. For DLC, key strategies include nanocrystalline/multilayer designs, doping, and interface engineering to mitigate high stress and poor adhesion. Tribological enhancement relies on graphitization, C-σ bond passivation, and tribochemistry, while corrosion resistance is achieved through densification, multilayer architectures, and barrier layers. Diamond film discussions cover micro-/nano-/ultrananocrystalline synthesis, morphology-dependent tribology, and inherent sp³-network corrosion resistance. Deposition advances enable conformal DLC films on complex parts and scalable diamond synthesis. By integrating both materials into a unified framework, this work highlights their complementary roles: diamond as the performance benchmark, DLC as the adaptable solution. Future efforts should link material fundamentals to industrial needs, emphasizing interfacial adhesion and extreme-environment performance to broaden applications in aerospace, automotive, precision engineering, and biomedical fields.

Diamond has many excellent physicochemical properties including ultrahigh hardness, wide bandgap, outstanding thermal conductivity, and high electron mobility, which has emerged as a critical material for high-power electronics, quantum technologies, and micro/nano-electromechanical systems (MEMS/NEMS). Single crystalline diamond tends to have better performance than polycrystalline diamond in some fields including thermal management, optics and quantum information. However, its extreme hardness and chemical inertness pose significant challenges for scalable microfabrication and require specialized techniques beyond conventional silicon-based processes. This paper systematically summarizes the latest progress in single crystalline diamond (SCD) MEMS manufacturing, including the diamond growth achieved through high pressure and high temperature (HPHT) or chemical vapor deposition (CVD), two-dimensional (2D) nanostructures achieved through inductively coupled plasma (ICP) etching and focused ion beam (FIB) milling and three-dimensional (3D) structures achieved through ion implant-assisted exfoliation (IAL), diamond on insulator (DOI), and angled etching strategies. We focused on introducing the applications of SCD in thermal management, photonic device, quantum systems, and heterojunctions. However, there are still some challenges, such as high fabrication costs, interfacial thermal resistance in hetero-integrated devices, and limitations in n-type doping efficiency. Emerging approaches like deep elastic strain engineering (DESE) can offer novel pathways to regulate SCD’s electronic and quantum properties. In the future, interdisciplinary combination in materials science, nanofabrication, and quantum engineering are critical to for next-generation electronics, quantum information, and MEMS technologies of diamond.

The main idea of this work was to investigate the voltammetric behavior of theophylline using cyclic voltammetry (CV), and to compare differential pulse voltammetry (DPV) and square wave voltammetry (SWV) for application in the development of a method for this analyte. The electrochemical results indicate that the homely printed sensor with a boron doped diamond electrode can significantly improve the electrocatalytic activity towards the oxidation of theophylline in 0.5 M sulfuric acid. After parameter optimization and comparison of the DPV and SWV methods, it was shown that both methods can effectively detect theophylline in the same concentration range from 3.8 to 27 µM. Slightly better analytical parameters in terms of detection limit and quantification limit were obtained by the SWV method and were 0.24 µM and 0.73 µM, respectively. In the case of DPV, the detection limit was 0.39 µM, while the quantification limit was at a value of 1.17 µM. The practical applicability was demonstrated through the development of the SWV method for the detection of theophylline in pharmaceutical formulations. The tests were performed in triplicate and using the standard addition method. Excellent agreement with the declared values showed that the proposed sensor can be a satisfactory alternative for fast, precise and accurate monitoring of theophylline concentration in real samples, with great potential for further modification and technology transfer for miniaturization and disposable sensing.

The precise characterization of bulk properties of thin homoepitaxial diamond layers with micrometer thickness is difficult due to the interference from the substrate. In this work, we utilized smart-cut method to fabricate single-crystal diamond (SCD) cantilevers or plates and transferred them to a foreign substrate (SiO2/Si). The mechanical resonance of the SCD cantilevers was characterized to confirm that the ion-implantation-induced damaged layer was nearly removed under the cantilever. Raman, photoluminescence (PL), and cathodoluminescence (CL) measurements were conducted on the transferred SCD cantilevers/plates and homoepitaxial layers on the substrate with and without ion implantation. As a result, it was found that both of the Raman spectral properties of the SCD layer on the ion-implanted regions and the freestanding SCD plates/cantilevers successfully avoid interference from the substrate. PL analysis showed no emission peaks attributable to nitrogen and other defects from the epilayers. Additionally, CL analysis from the freestanding cantilevers/plates disclosed the exciton emission at around 236 nm at room temperature. These results suggest the high crystal quality of the SCD cantilevers for MEMS applications.

Strain engineering, a pivotal method for tuning material properties, shows great promise in extending the application scope of wide-band-gap semiconductors such as diamond. Nitrogen-vacancy (NV) centers, an important defect system in diamond, are generally present in either a neutral (NV0) or a negative charge state (NV−). The spin-triplet nature of the NV− state makes it a powerful platform for quantum sensing. However, the reliability of NV-center-based quantum sensing is subjected to the charge state transition between NV0 and NV− states, and it is of fundamental importance to provide precise control of the charge state of NV centers and to enhance the stability of the NV− state. Here, we systematically investigated the influence of uniaxial strain applied in the [100], [110], and [111] crystallographic directions on the electronic structure and charge state stability of NV color centers through first-principles calculations. We found that uniaxial strain can exert a significant impact on the stability of the NV0 and NV− centers, and the impact is highly dependent on the crystallographic orientation. In particular, the application of tensile strain along the [100] and [110] directions can result in a remarkable enhancement of the stability of the desired NV− state. Based on thorough analyses of the band structure and density of states (DOS), we elucidated the underlying electronic mechanism by which strain modulates the properties of NV centers.

Nitrogen-vacancy (NV) color centers in diamond have emerged as a focal point in quantum technology research due to their exceptional optical and electronic spin properties. This discovery not only expands our understanding of the material properties of diamond but also paves the way for practical applications in quantum technology. As a solid-state spin quantum system characterized by long electron spin coherence times and stable performance, NV color centers offer distinct advantages in quantum information processing. Recent advancements have enabled the fabrication of high-quality NV color centers with controllable concentration and spatial positioning through techniques such as in situ doping, ion implantation, and hybrid approaches. These technological breakthroughs have significantly enhanced the efficiency of NV center fabrication, thereby establishing a robust foundation for their widespread application in quantum sensing and quantum information technologies. This review provides a compre­hensive introduction to the structure and fundamental properties of NV color centers in diamond, an in-depth analysis of recent progress in their fabrication techniques, and a critical discussion of their current applications in quantum science and technology. Additionally, the challenges, open questions, and future research directions in NV color center studies are addressed.

Diamond offers excellent heat sink for high power high-electron-mobility transistors based on III-nitrides. However, the GaN/diamond interfaces suffer from low thermal conductance due to phonon mismatch. Although AlN interlayers can mitigate this issue, processing-induced carbon vacancies and subsurface disorder near the AlN/diamond interface recreate a new thermal bottleneck. In this study, we employ deep learning-enhanced non-equilibrium molecular dynamics (NEMD) simulations to investigate atomic-scale thermal transport across AlN/diamond interfaces, with a particular focus on quantifying the impact of carbon vacancies. Results show interfacial thermal conductance (ITC) for AlN-Al/C(1 1 1) depends non-monotonically on the carbon vacancy concentration. The ITC peaks at 151.7 MW·m−2K−1 at a carbon vacancy concentration of 2.4% due to the formation of resonant vibrational states that bridge the phonon gap and promote phonon delocalization, enabling efficient tunneling across the interface. However, beyond this optimal concentration, vacancy clustering induces destructive phonon interference, strong scattering, and severe localization effects, leading to a sharp decline in ITC. This work provides a pathway for optimizing AlN thermal bridges to achieve low thermal resistance in GaN-on-diamond devices through precise control of vacancy concentration and crystallinity.