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Спутники
РН
SpaceX
Роскосмос
NASA
СпутникиРНSpaceXРоскосмосNASAThe intrinsic properties of ultra-wide-bandgap semiconductors are exceptional. Diamond alone combines a bandgap of 5.47 eV, a theoretical breakdown field exceeding 10 MV/cm, and a thermal conductivity unmatched by any other semiconductor material. Whether these properties translate into working devices is determined not only by the bulk crystal but also by the atomic and electronic structure of its surface. This dissertation establishes, through first-principles calculations, how atomic-scale bonding at surfaces and interfaces governs the electronic properties that cannot be understood from the bulk structure alone.
The diamond (100) surface reconstructs without an activation barrier, driving a metallic-to-semiconducting transition. In contrast, the diamond (111) surface admits a secondary pathway through a previously unidentified metastable intermediate, with the final reconstructed surface remaining semi-metallic. These reconstructed surfaces serve as the structural and...