Structural transition of pentacene monolayer on Ga bilayer: From brick-wall structure to herringbone pattern of molecular dimers

Scanning-induced structure transformation between self-assembled phases of pentacene on Ag/Si(111)

“…These manipulation experiments are mostly performed locally, or on individual molecules, while tip-induced structure transformation in large area has not been much studied so far. For pentacene, STM tip-induced local structure rearrangement has been recently observed on the Sið1 Ga film surface by Wang et al [16]. The observation on Ag=Si-ffiffi ffi 3 p raises a puzzling question: where are the excess pentacene molecules from, since the local density of molecules increases significantly after the structure change.…”

“…The condition for a given growth mode is determined by a delicate balance of the intralayer and overlayer-substrate interactions. For example, pentacene molecules stand up and form bulk crystalline phase or the thin film phase on insulating or inert surfaces such as SiO 2 , SiN, Al 2 O 3 and passivated Si [6][7][8], while they lie down and form varied 2D patterns (strip, brick-wall or herringbone) on noble metals [9][10][11][12][13] or some metallic interfaces [14][15][16] where the molecule-substrate interactions surpass the molecule-molecule interactions and lead to a planar adsorption geometry.…”

Structural transition of pentacene monolayer on Cd(0001)

“…在Cu(111)表面, 并五 苯单层出现两种特别的结构: 二维的"鲱鱼骨"(Herringbone)结构和"随机镶嵌"(Random-tiling)结构 [20] . 在 半金属的Ga薄膜表面, 并五苯分子会形成以二聚体为 基本单元的"鲱鱼骨"结构, 同时退火处理可以导致"砖 墙"结构到"鲱鱼骨"结构的转变 [21] . 并五苯没有任何极 性官能团, 是一个典型的简单非手性分子.…”

“…但研究发现 并五苯分子在半金属的Bi(111)衬底的台阶附近形成 两种相反手性的风车团簇 [22] . Ga表面以及Ag(110), Ag(111)和Au(111)表面的情况类 似 [19,21,24,25] . 图 3 (网络版彩图)并五苯自组装的"鲱鱼骨"结构.…”

“…(a) 并五 苯分子的二维"鲱鱼骨"结构的STM高分辨图, 9 nm×9 nm, 1.6 V; (b) "鲱鱼骨"排列的结构示意图 石明霞等. 中国科学: 物理学 力学 天文学 2018 年 第 48 卷 第 11 期 117002-3 https://engine.scichina.com/doi/10.1360/SSPMA2018-00105 在Ga表面上的二维鲱鱼骨结构是由两种不同的并五 苯二聚体交错排列而成 [20,21] . 并五苯分子在Cd衬底表 面会采取"侧躺"或"平躺"的姿态, 取决于分子-衬底和 [28] .…”