Surface morphology of vacuum-evaporated pentacene film on Si substrate studied by in situ grazing-incidence small-angle X-ray scattering: I. The initial stage of formation of pentacene film
Surface morphology of vacuum-evaporated pentacene film on Si substrate studied by in situ grazing-incidence small-angle X-ray scattering: I. The initial stage of formation of pentacene film
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DOI：
10.7567/jjap.57.03eg12
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发表时间：
2018-02
影响因子：
1.5
通讯作者：
I. Hirosawa;Takeshi Watanabe;T. Koganezawa;M. Kikuchi;N. Yoshimoto
中科院分区：
文献类型：
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作者：
I. Hirosawa;Takeshi Watanabe;T. Koganezawa;M. Kikuchi;N. Yoshimoto
采用原位掠入射小角x射线散射（GISAXS）研究了在Si衬底上生长的亚单层五苯薄膜的表面形貌。观测到的GISAXS剖面没有显示出并五苯岛的大小，而主要是在并五苯膜周围的边界上的突起。在几乎完全覆盖的薄膜的GISAXS剖面中也检测到并五苯薄膜中残留凹坑对x射线的散射。并五苯突起的平均半径随着覆盖度的增加而增加，从13 nm增加到24 nm，最常见的半径几乎不变，约为9 nm。这一结果表明，较大的突起数量随着并五苯膜边界长度的增加而增加。也可以认为检测到的突起是并五苯的结晶，因为突起的平均尺寸与并五苯薄膜的晶粒尺寸几乎相等。610 nm的特征距离几乎不变，低覆盖率下的对相关函数的振幅表明，并五苯薄膜的生长符合先前报道的扩散限制聚集（DLA）模型。人们还认为，岛屿的地点对估计的相关距离的小变化呈三角形分布。
The progress of the surface morphology of a growing sub-monolayered pentacene film on a Si substrate was studied by in situ grazing-incidence small angle X-ray scattering (GISAXS). The observed GISAXS profiles did not show sizes of pentacene islands but mainly protuberances on the boundaries around pentacene film. Scattering of X-ray by residual pits in the pentacene film was also detected in the GISAXS profiles of an almost fully covered film. The average radius of pentacene protuberances increased from 13 to 24 nm as the coverage increased to 0.83 monolayer, and the most frequent radius was almost constant at approximately 9 nm. This result suggests that the population of larger protuberances increase with increasing lengths of boundaries of the pentacene film. It can also be considered that the detected protuberances were crystallites of pentacene, since the average size of protuberances was nearly equal to crystallite sizes of pentacene films. The almost constant characteristic distance of 610 nm and amplitudes of pair correlation functions at low coverages suggest that the growth of pentacene films obeyed the diffusion-limited aggregation (DLA) model, as previously reported. It is also considered that the sites of islands show a triangular distribution for small variations of estimated correlation distances.