Morozov Konstantin M, Ivanov Konstantin A, de Sa Pereira Daniel, Menelaou Christopher, Monkman Andrew P, Pozina Galia, Kaliteevski Mikhail A
ITMO University, 197101, St. Petersburg, Russia.
St. Petersburg Academic University, 194021, St. Petersburg, Russia.
Sci Rep. 2019 Jul 3;9(1):9604. doi: 10.1038/s41598-019-46071-5.
Periodic metal-dielectric structures attract substantial interest since it was previously proposed that the spontaneous emission amplification rates (the Purcell factor) in such structures can reach enormous values up to 10. However, the role of absorption in real metals has not been thoroughly considered. We provide a theoretical analysis showing that absorption leads to diminishing values of Purcell factor. We also suggest that using emitting organic compounds such as CBP (4,4-Bis(N-carbazolyl)-1,1-biphenyl) can lead to a moderate increase of about an order of magnitude in the Purcell factor. Defining the experimentally measured Purcell factor as a ratio between the excited state lifetimes in bare CBP and in periodic structure, this increase in the fabricated periodic structure is demonstrated through a 4-8 times decrease in excited state radiative lifetime compared to a bare organic material in a wide emission spectrum.
周期性金属-电介质结构引起了人们的广泛关注，因为此前有人提出，此类结构中的自发辐射放大率（珀塞尔因子）可高达巨大值10。然而，实际金属中吸收的作用尚未得到充分考虑。我们进行了理论分析，结果表明吸收会导致珀塞尔因子值减小。我们还提出，使用诸如CBP（4,4-双（N-咔唑基）-1,1-联苯）之类的发光有机化合物可使珀塞尔因子适度增加约一个数量级。将实验测量的珀塞尔因子定义为裸CBP和周期性结构中激发态寿命的比值，通过与宽发射光谱中的裸有机材料相比，激发态辐射寿命降低4-8倍，证明了所制备周期性结构中珀塞尔因子的这种增加。
