We analyze the light emission induced by the tunneling current flowing in a scanning tunneling microscopy experiment. In particular, we study the influence of organic ad-layers on the light emission on the initial monolayer of bismuth (Bi) on Cu(111) in comparison to the well-known case of organic ad-layers on Ag(111). On the Bi/Cu(111)-surface, we find that the scanning tunneling microscopy-induced light emission is considerably enhanced if an organic layer, e.g., the fullerene C60 or the perylene derivate perylene-tetracarboxylic-dianhydride, is introduced into the tip-sample junction. The enhancement can be correlated with a peculiarly weak interaction between the adsorbed molecules and the underlying Bi/Cu(111) substrate as compared to the Ag(111) substrate. This allows us to efficiently enhance and tune the coupling of the tunneling current to localized excitations of the tip-sample junction, which in turn couple to radiative decay channels.

中文翻译：

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弱耦合有机广告层增强了 STM 诱导的光发射

我们分析了在扫描隧道显微镜实验中由隧道电流引起的光发射。特别是，与众所周知的 Ag(111) 上有机 ad 层的情况相比，我们研究了有机 ad 层对 Cu(111) 上铋 (Bi) 初始单层的光发射的影响。在 Bi/Cu(111) 表面，我们发现如果将有机层（例如富勒烯 C60 或苝衍生物苝四羧酸二酐）引入尖端，则扫描隧道显微镜诱导的光发射显着增强-样品结。与 Ag(111) 衬底相比，这种增强可能与吸附分子和下面的 Bi/Cu(111) 衬底之间的特别弱的相互作用有关。