论文标题
通过氧化还原的电荷掺杂，从双层石墨烯中从双层石墨烯中产生强的第二次谐波生成
Strong Second Harmonic Generation from Bilayer Graphene with Symmetry Breaking by Redox-Governed Charge Doping
论文作者
论文摘要
中心对称石墨烯中缺少二阶非线性，使其有趣的光学属性遮盖了阴影。在这里，我们报告说，氧化还原的电荷掺杂可能有效地打破了双层石墨烯（BLG）的中心对称性，从而实现了强大的第二次谐波生成（SHG），其强度接近众所周知的单层MOS2。通过对照实验进行了现场电流退火和电气控制的SHG的对照实验，所需的中心对称性破裂是由氧气/水氧化夫妇夫妇在BLG底层的电荷掺杂产生的。我们的结果不仅揭示了电荷掺杂是破坏BLG的反转对称性的有效方法，尽管它具有强大的层间耦合，而且还表明SHG光谱是一种有效的技术，可以在二维材料上探测分子掺杂。
Missing second-order nonlinearity in centrosymmetric graphene overshadows its intriguing optical attribute. Here, we report redox-governed charge doping could effectively break the centrosymmetry of bilayer graphene (BLG), enabling a strong second harmonic generation (SHG) with a strength close to that of the well-known monolayer MoS2. Verified from control experiments with in situ electrical current annealing and electrically gate-controlled SHG, the required centrosymmetry breaking of the emerging SHG arises from the charge-doping on the bottom layer of BLG by the oxygen/water redox couple. Our results not only reveal that charge doping is an effective way to break the inversion symmetry of BLG despite its strong interlayer coupling but also indicate that SHG spectroscopy is a valid technique to probe molecular doping on two-dimensional materials.
