Abstract The preparation of an atomically thin sheet of graphene/h-BN (GBN) hybrid with lack of defects is almost unachievable as in three dimensional crystals. Here, we first discussed the stability and electronic properties of GBN hybrid nanosheet which is formed by implanting a diamond shaped graphene (G) island into the hexagonal boron nitride (h-BN) layout. We further investigated the effects of mono vacancy on the electronic and magnetic properties of defective GBN nanosheet. The band gap of pristine hybrid decreases with growing G island as expected and the island induces flat (dispersionless) energy bands near the Fermi energy of the h-BN nanosheet. We searched for the energetics of 7 distinct C, B and N mono vacancies created at various places such as h-BN region, G region and interface of the optimized pristine hybrid. The G-BN interface is found as the energetically most favourable place for vacancy formation. Depending on the size of the graphene island, the C vacancy is the most favourable defect type in our DFT calculations. The N vacancy is energetically preferred over the B vacancy due to its lower formation energy with the exception of biggest G island. Although pristine hybrids are non-magnetic semiconductors, the GBN hybrid can become magnetic with a reasonable amount of magnetic moment depending on the type of vacancy and vacancy site. The vacancy defected hybrids also show the properties of semiconductor except for the hybrid involving the smallest size island with the B vacancy in the h-BN layout (VBL). Defected hybrids involving the smallest G island have the highest amount of band gaps due to high ratio of carbon atoms at the interface to the island interior. Accordingly, the band gap tends to decrease with expanding G island. However, the band gap of VBL defected structures broadens with increasing size of island interestingly. Moreover, this defected hybrid introduces the greatest amount of magnetic moment (3 μ B ) as the island expands. The C vacancies in the G island and around the N atom introduce a magnetic moment of 2 μ B as the G island expands as well. The magnetic moment of the N vacancy defected hybrid is 1 μ B irrespective of island size. The vacancy defect leads local in-plane/out-of-plane distortions rather than structural reconstructions in our calculations. In general, no correlation was observed between the island size and the magnetic moment of a defective hybrid.

中文翻译：

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研究单空位对石墨烯六方氮化硼面内杂化环抱菱形石墨烯岛的结构、电子和磁性能的影响

摘要 制备无缺陷的石墨烯/h-BN (GBN) 杂化物原子薄片几乎无法像三维晶体那样制备。在这里，我们首先讨论了通过将菱形石墨烯 (G) 岛注入六方氮化硼 (h-BN) 布局而形成的 GBN 混合纳米片的稳定性和电子特性。我们进一步研究了单空位对有缺陷的 GBN 纳米片的电子和磁性的影响。正如预期的那样，原始杂化物的带隙随着 G 岛的增长而减小，并且该岛在 h-BN 纳米片的费米能量附近诱导平坦（无色散）能带。我们搜索了在不同位置产生的 7 个不同的 C、B 和 N 单空位的能量学，例如 h-BN 区域、G 区域和优化的原始混合体的界面。G-BN 界面被认为是最有利于空位形成的地方。根据石墨烯岛的大小，C 空位是我们 DFT 计算中最有利的缺陷类型。除了最大的 G 岛外，N 空位在能量上优于 B 空位，因为它的形成能较低。尽管原始混合体是非磁性半导体，但 GBN 混合体可以根据空位和空位位置的类型以合理的磁矩量变为磁性。除了在 h-BN 布局 (VBL) 中涉及最小尺寸岛和 B 空位的混合之外，空位缺陷杂化也显示出半导体的特性。由于与岛内部界面处的碳原子比例高，涉及最小 G 岛的缺陷杂化体具有最高的带隙量。因此，随着G岛的扩大，带隙趋于减小。然而，有趣的是，VBL 缺陷结构的带隙随着岛尺寸的增加而变宽。此外，随着岛的扩展，这种有缺陷的混合体引入了最大量的磁矩（3μB）。随着 G 岛的扩展，G 岛和 N 原子周围的 C 空位引入了 2 μ B 的磁矩。N 空位缺陷杂化体的磁矩为 1 μ B，与岛大小无关。在我们的计算中，空位缺陷导致局部平面内/平面外扭曲，而不是结构重建。一般来说，