Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
Phys Rev Lett. 2011 Jul 1;107(1):017402. doi: 10.1103/PhysRevLett.107.017402.
We visualize exciton diffusion in rubrene single crystals using localized photoexcitation and spatially resolved detection of excitonic luminescence. We show that the exciton mobility in this material is strongly anisotropic with long-range diffusion by several micrometers associated only with the direction of molecular stacking in the crystal, along the b axis. We determine a triplet exciton diffusion length of 4.0 ± 0.4 μm from the spatial exponential decay of the photoluminescence that originates from singlet excitons formed by triplet-triplet fusion.
我们使用局域光激发和激子发光的空间分辨检测来可视化并芴单晶中的激子扩散。我们表明，该材料中的激子迁移率具有强烈的各向异性，长程扩散可达数微米，这仅与晶体中分子堆积的方向（b 轴方向）有关。我们从源于三重态-三重态复合形成的单重态激子的光致发光的空间指数衰减确定三重态激子的扩散长度为 4.0 ± 0.4 μm。
