Impact of free charged carrier concentration on the atomic core structure and electronic properties of dislocations in gallium nitride

这个项目的起点是与彼得堡的合作 州立大学和Georg-August-Universität Göttingen提出的假设是，自由电子在位错处被捕获到堆垛层错带状量子阱的电子态会影响它们的核心结构，进而影响GaN中位错的电子性质。我们计划首次系统地研究GaN晶体中塑性变形引入的位错的原子核结构对它们的导电类型和自由载流子浓度的依赖性。将在相同的样品上监测DRL和电子水平，这允许建立位错芯结构和电子性质之间的相关性。作为进一步的重要方面，电子激发对运动位错的影响将被分析和量化。DRL的这种费米能级依赖的原子核结构和光谱位置的主要含义是通过外部手段（例如，通过施加到肖特基二极管的空间电荷区域的外部电压）电子地切换核结构的可能性。因此，可以预期DRL光谱响应对于位于肖特基二极管中一定深度处的位错应该在一定范围内（现在在3.15 eV和3.35 eV之间）变化。在本项目中，将对这一假设进行检验。该项目的一个远景目标是开辟基于DRL的极高效发光二极管的生产路线。最先进的晶圆键合技术与SmartCut技术相结合，可以在数百纳米的样品深度上产生工业上规则的螺旋位错网络。已经生产了基于硅键合晶片中的DRL的这种LED。

The starting point of this project which is a cooperation of the Petersburg State University and the Georg-August-Universität Göttingen, is the hypothesis the capture of free electrons to electron states of the stacking fault ribbon quantum well at dislocations affects their core structure and, in turn, electronic properties of dislocations in GaN. For the first time we plan to investigate systematically the dependence of the atomic core structure of dislocations introduced by plastic deformation in GaN crystals on their conductivity type and free carrier concentration. DRL and electrical levels will be monitored on the same samples which allows to establish correlations between dislocation core structure and electronic properties. As a further important aspect, the impact of electron excitation on the motion dislocations will be analyzed and quantified. A major implication of this Fermi-level-dependent atomic core structure and spectral position of DRL would be the possibility to electronically switch the core structure by external means, e.g. by the external voltage applied to the space charge region of a Schottky diode. Accordingly, one may expect that the DRL spectral response should change in some ranges (now between 3.15 eV and 3.35 eV) for dislocations situated at a certain depth in Schottky diode. This assumption is intended be checked in this project. A perspective goal of the project is to open the route to the production of extremely high efficient light emitting diodes based on DRL. The state-of-the art wafer bonding technology in the combination with SmartCut technique allows to produce industrially regular networks of screw dislocation on the sample depth of hundreds of nanometers. Such LEDs based on DRL in silicon bonded wafers have been already produced.