论文标题
GAN中的稀土缺陷：对灯笼序列的系统研究
Rare-earth defects in GaN: A systematic investigation of the lanthanide series
论文作者
论文摘要
稀土（Re）掺杂的GAN对于光电和旋转三位型含量很感兴趣，并且有可能用于量子应用。对掺杂剂与半导体宿主之间的相互作用的基本理解是实现材料的全部潜力的关键。这项工作报告了使用混合密度官能缺陷计算对GAN中灯笼（$ LN $）缺陷的调查。我们发现，GA晶格网站上的所有$ LN $ dopants $ ln _ {\ rm ga} $（$ ln $ = la-lu）都是稳定的，但也可以稳定为eu和yb，也可以稳定为divalent and ce，pr，pr和tb and tb as tetravalent。 $ LN $相关的缺陷水平和$ LN $ 4F $ $ $ $ 4F $的位置是从第一原则确定的。我们阐明了缺陷形成与电子结构之间的相互作用，包括$ LN $ - N相互作用以及掺杂对当地晶格环境的影响。通过考虑涉及$ ln _ {\ rm ga} $具有间隙能级的缺陷，研究了光学特性，以及带有$ ln _ {\ rm ga} $的过渡，包括广泛的“电荷转移”过渡。这些缺陷还可以充当载体陷阱，并介导从宿主到$ LN $ ion的$ 4F $ - 电子核心的能源转移，从而导致急剧的内部内部发光。
Rare-earth (RE) doped GaN is of interest for optoelectronics and spintronics and potentially for quantum applications. A fundamental understanding of the interaction between RE dopants and the semiconductor host is key to realizing the material's full potential. This work reports an investigation of lanthanide ($Ln$) defects in GaN using hybrid density-functional defect calculations. We find that all the $Ln$ dopants incorporated at the Ga lattice site, $Ln_{\rm Ga}$ ($Ln$ = La--Lu), are stable as trivalent ions, but Eu and Yb can also be stabilized as divalent and Ce, Pr, and Tb as tetravalent. The location of $Ln$-related defect levels and the $Ln$ $4f$ states in the energy spectrum of the host material is determined from first principles. We elucidate the interplay between defect formation and electronic structure, including the $Ln$--N interaction, and the effect of doping on the local lattice environment. Optical properties are investigated by considering possible defect-to-band and band-to-defect transitions involving $Ln_{\rm Ga}$ defects with in-gap energy levels, including broad "charge-transfer" transitions. These defects can also act as carrier traps and mediate energy transfer from the host into the $4f$-electron core of the $Ln$ ion which leads to sharp intra-$f$ luminescence.
