Abstract We report on the structural and transport properties of the smallest dislocation loop in graphene, known as a flower defect. First, by means of advanced experimental imaging techniques, we deduce how flower defects are formed during recrystallization of chemical vapor deposited graphene. We propose that the flower defects arise from a bulge type mechanism in which the flower domains are the grains left over by dynamic recrystallization. Next, in order to evaluate the use of such defects as possible building blocks for all-graphene electronics, we combine multiscale modeling tools to investigate the structure and the electron and phonon transport properties of large monolayer graphene samples with a random distribution of flower defects. For large enough flower densities, we find that electron transport is strongly suppressed while, surprisingly, hole transport remains almost unaffected. These results suggest possible applications of flowered graphene for electron energy filtering. For the same defect densities, phonon transport is reduced by orders of magnitude as elastic scattering by defects becomes dominant. Heat transport by flexural phonons, key in graphene, is largely suppressed even for very low concentrations.

中文翻译：

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开花石墨烯的生长、电荷和热传输

摘要我们报告了石墨烯中最小位错环的结构和传输特性，称为花缺陷。首先，通过先进的实验成像技术，我们推断出化学气相沉积石墨烯在重结晶过程中如何形成花缺陷。我们提出花缺陷是由膨胀型机制引起的，其中花域是动态再结晶留下的晶粒。接下来，为了评估使用此类缺陷作为全石墨烯电子学的可能构建块，我们结合多尺度建模工具来研究具有随机分布的花缺陷的大型单层石墨烯样品的结构以及电子和声子传输特性。对于足够大的花密度，我们发现电子传输受到强烈抑制，而 令人惊讶的是，空穴传输几乎不受影响。这些结果表明有花石墨烯在电子能量过滤方面的可能应用。对于相同的缺陷密度，由于缺陷的弹性散射占主导地位，声子传输减少了几个数量级。弯曲声子的热传输是石墨烯的关键，即使浓度非常低，也很大程度上受到抑制。