Khabir Kanij Mehtanin, Shahabuddin Mohammad, Noginova Natalia, Noginov Mikhail A
Center for Materials Research, Norfolk State University, Norfolk, VA, 23504, USA.
Sci Rep. 2024 Aug 5;14(1):18044. doi: 10.1038/s41598-024-68742-8.
Work function is an essential material's property playing important roles in electronics, photovoltaics, and more recently, in nanophotonics. We have studied effects of organic, and inorganic dielectric materials on work functions of Au films in single layered, and multilayered structures. We found that measured work function of metallic surfaces can be affected by dielectric materials situated 10-100 nm away from the metallic surface. We have found that, (i) the glass underneath ~ 50 nm gold slab reduces the work function of gold, (ii) Rh590:PMMA increases the work function of a gold film deposited on top of the polymer, and (iii) reduces it if Rh590:PMMA is deposited on top of Au. (iv) With increase of the Rh590 concentration in PMMA, n, the work function first decreases (at n < 64 g/l), and then increases (at n > 64 g/l). (v) The work function of a Fabry-Perot cavity or an MIM waveguide is almost the same as that of single Au films of comparable thickness. The experimental results can be qualitatively explained in terms of a simple model taking into account adhesion of charged molecules to a metallic surface, and formation of a double layer of charges accelerating or decelerating electrons exiting the metal and decreasing or increasing the work function.
功函数是一种重要的材料特性，在电子学、光伏领域，以及最近在纳米光子学中都发挥着重要作用。我们研究了有机和无机介电材料对单层和多层结构中Au膜功函数的影响。我们发现，距金属表面10 - 100 nm处的介电材料会影响金属表面的测量功函数。我们发现，（i）~50 nm金板下方的玻璃会降低金的功函数，（ii）Rh590:PMMA会增加沉积在聚合物顶部的金膜的功函数，而（iii）如果将Rh590:PMMA沉积在Au顶部则会降低其功函数。（iv）随着PMMA中Rh590浓度n的增加，功函数先降低（n < 64 g/l时），然后增加（n > 64 g/l时）。（v）法布里 - 珀罗腔或MIM波导的功函数与厚度相当的单层Au膜的功函数几乎相同。实验结果可以用一个简单的模型进行定性解释，该模型考虑了带电分子对金属表面的附着，以及电荷双层的形成，这种双层会加速或减速离开金属的电子，从而降低或增加功函数。
