Shalem Guy, Erez-Cohen Omer, Mahalu Diana, Bar-Joseph Israel
Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
Nano Lett. 2021 Feb 10;21(3):1282-1287. doi: 10.1021/acs.nanolett.0c03945. Epub 2021 Jan 26.
We study metal-insulator-semiconductor tunnel junctions where the metal electrode is a patterned gold layer, the insulator is a thin layer of AlO, and the semiconductor is p-type silicon. We observe light emission due to plasmon-assisted inelastic tunneling from the metal to the silicon valence band. The emission cutoff shifts to higher energies with increasing voltage, a clear signature of electrically driven plasmons. The cutoff energy exceeds the applied voltage, and a large fraction of the emission is above the threshold, ℏω > . We find that the emission spectrum manifests the Fermi-Dirac distribution of the electrons in the gold electrode. This distribution can be used to determine the effective electron temperature, , which is shown to have a linear dependence on the applied voltage. The strong correlation of with the plasmon energy serves as evidence that the mechanism for heating the electrons is plasmon decay at the source metal electrode.
我们研究了金属-绝缘体-半导体隧道结，其中金属电极是图案化的金层，绝缘体是AlO薄层，半导体是p型硅。我们观察到由于等离子体激元辅助的非弹性隧穿从金属到硅价带而产生的光发射。随着电压增加，发射截止能量向更高能量移动，这是电驱动等离子体激元的明显特征。截止能量超过施加电压，并且很大一部分发射高于阈值，ħω > 。我们发现发射光谱体现了金电极中电子的费米-狄拉克分布。这种分布可用于确定有效电子温度， ，结果表明它与施加电压呈线性关系。 与等离子体激元能量的强相关性证明了电子加热机制是源金属电极处的等离子体激元衰变。
