论文标题
GAN中缺陷对的第一原理探索
First-Principles Exploration of Defect-Pairs in GaN
论文作者
论文摘要
使用第一原理计算，我们探索了GAN中的所有21个缺陷对，并考虑了每种缺陷对的6个具有不同缺陷 - 缺陷距离的配置。在结构弛豫期间发现15对缺陷缺陷距离的缺陷对稳定，因此它们可以存在于高能颗粒辐照过程中曾经形成的gan晶格中。在中性状态下，9个缺陷对具有低于10 eV的地层能。发现空缺对VN-VN的形成能非常低，在P型和富含GA的GAN中低至0 eV，并且充当产生两个深层供体水平的有效供体，这可以限制GAN中P型掺杂和少数族裔载体寿命。 VN-VN在先前对GAN缺陷的研究中被忽略了。这些缺陷对中的大多数充当捐助者，并在带隙中产生大量的缺陷水平。它们的形成能和浓度对GA和N的化学电位敏感，因此它们对辐照后富含Ga和N的GAN的电气和光学特性的影响应显着差异。这些有关缺陷对的结果提供了基本数据，以了解GAN中的辐射损伤机制，并模拟照射下的缺陷形成和扩散行为。
Using first-principles calculations, we explored all the 21 defect-pairs in GaN and considered 6 configurations with different defect-defect distances for each defect-pair. 15 defect-pairs with short defect-defect distances are found to be stable during structural relaxation, so they can exist in the GaN lattice once formed during the irradiation of high-energy particles. 9 defect-pairs have formation energies lower than 10 eV in the neutral state. The vacancy-pair VN-VN is found to have very low formation energies, as low as 0 eV in p-type and Ga-rich GaN, and act as efficient donors producing two deep donor levels, which can limit the p-type doping and minority carrier lifetime in GaN. VN-VN has been overlooked in the previous study of defects in GaN. Most of these defect-pairs act as donors and produce a large number of defect levels in the band gap. Their formation energies and concentrations are sensitive to the chemical potentials of Ga and N, so their influences on the electrical and optical properties of Ga-rich and N-rich GaN after irradiation should differ significantly. These results about the defect-pairs provide fundamental data for understanding the radiation damage mechanism in GaN and simulating the defect formation and diffusion behavior under irradiation.
