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

这个项目是圣彼得堡国立大学和Georg-August-Universität Göttingen合作的，其出发点是假设自由电子在位错处被捕获到堆叠错带量子阱的电子态会影响它们的核心结构，进而影响氮化镓中位错的电子性质。我们计划首次系统地研究GaN晶体中由塑性变形引入的位错原子核心结构与它们的电导率类型和自由载流子浓度的关系。将在同一样品上监测DRL和电水平，从而建立位错核心结构与电子特性之间的相关性。作为另一个重要方面，电子激发对运动位错的影响将被分析和量化。这种与费米能级相关的原子核心结构和DRL的光谱位置的一个主要含义是通过外部手段（例如通过施加在肖特基二极管的空间电荷区上的外部电压）电子开关核心结构的可能性。因此，人们可以预期，对于肖特基二极管中位于一定深度的位错，DRL光谱响应应该在某些范围内（现在在3.15 eV和3.35 eV之间）发生变化。这个假设将在本项目中进行检验。该项目的一个远景目标是为基于DRL的极高效发光二极管的生产开辟道路。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规则的螺旋位错网络。这种基于DRL的硅晶片led已经生产出来。

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.