Glasses prepared by physical vapor deposition (PVD) are anisotropic, and the average molecular orientation can be varied significantly by controlling the deposition conditions. While previous work has characterized the average structure of thick PVD glasses, most experiments are not sensitive to the structure near an underlying substrate or interface. Given the profound influence of the substrate on the growth of crystalline or liquid crystalline materials, an underlying substrate might be expected to substantially alter the structure of a PVD glass, and this near-interface structure is important for the function of organic electronic devices prepared by PVD, such as organic light-emitting diodes. To study molecular packing near buried organic–organic interfaces, we prepare superlattice structures (stacks of 5- or 10-nm layers) of organic semiconductors, Alq3 (Tris-(8-hydroxyquinoline)aluminum) and DSA-Ph (1,4-di-[4-(N,N-diphenyl)amino]styrylbenzene), using PVD. Superlattice structures significantly increase the fraction of the films near buried interfaces, thereby allowing for quantitative characterization of interfacial packing. Remarkably, both X-ray scattering and spectroscopic ellipsometry indicate that the substrate exerts a negligible influence on PVD glass structure. Thus, the surface equilibration mechanism previously advanced for thick films can successfully describe PVD glass structure even within the first monolayer of deposition on an organic substrate.

通过物理气相沉积 (PVD) 制备的玻璃是各向异性的，通过控制沉积条件可以显着改变平均分子取向。虽然以前的工作已经描述了厚 PVD ​​玻璃的平均结构，但大多数实验对底层基板或界面附近的结构并不敏感。考虑到基板对晶体或液晶材料生长的深远影响，下层基板可能会显着改变 PVD ​​玻璃的结构，这种近界面结构对于通过制备有机电子器件的功能很重要PVD，如有机发光二极管。研究埋藏有机-有机界面附近的分子堆积，N-二苯基）氨基]苯乙烯基苯），使用PVD。超晶格结构显着增加了掩埋界面附近的薄膜比例，从而可以定量表征界面堆积。值得注意的是，X 射线散射和光谱椭偏仪均表明基板对 PVD ​​玻璃结构的影响可以忽略不计。因此，先前用于厚膜的表面平衡机制可以成功地描述 PVD ​​玻璃结构，即使在有机基板上的第一个单层沉积中也是如此。