【作者】 田广军； 罗毅；

【Author】 Guangjun Tian;Yi Luo;College of Science,Yanshan University;Hefei National Laboratory for Physical Sciences at the Microscale,University of Science and Technology of China;

【机构】 燕山大学理学院； 中国科学技术大学合肥微尺度物质科学国家实验室；

【摘要】 利用扫描隧道显微镜（STM）中高度局域的隧穿电子可以激发吸附在其表面的分子体系并使之发射出光子。我们从理论计算的角度对这一过程进行了系统的研究,其中重点研究了STM针尖与衬底间形成的局域表面等离激元对分子发光特性的影响。为了同时处理隧穿电子和局域表面等离激元对分子的激发,我们发展了一套密度矩阵方法并利用这一方法对卟啉衍生物分子的STM电致发光行为进行了模拟。通过理论计算发现局域表面等离激元诱导产生的受激辐射是造成实验上观测到的分子电致发光光谱谱型改变的成因[1,2]。同时,我们通过将密度矩阵方法与第一性原理计算相结合计算出了C₆₀分子在STM激发下的荧光和磷光光谱。计算结果与实验结果符合的非常好,从而使得我们可以对实验上测得的发光光谱给出合理的指认[3]。更多还原

【Abstract】 We present our work on the theoretical modeling of STM tip induced electroluminescence（EL） from adsorbed molecules, focusing on the effect of the localized surface plasmon（LSP） generated under the STM tip. A density-matrix approach which could treat simultaneously the tunneling electron and LSP induced excitations was developed and successfully applied to investigate the EL properties of porphyrin derivatives. It was found that the spectral modification to the EL spectral as observed in the experiment is caused by the LSP induced emission[1,2]. We also calculated the fluorescence and phosphorescence spectra of C₆₀ molecule under the excitation of a STM by combing the density-matrix approach with first principles calculations. The simulation results nicely reproduced the observed EL spectra which enabled us to assign the measured spectra unambiguously[3].更多还原