Kelvin Probe Force Microscopy Images of Microstructured Organosilane Self-Assembled Monolayers
Kelvin Probe Force Microscopy Images of Microstructured Organosilane Self-Assembled Monolayers
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微结构有机硅烷自组装单分子层的开尔文探针力显微镜图像
DOI：
10.1143/jjap.40.4373
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发表时间：
2001
影响因子：
1.5
通讯作者：
N. Nakagiri
中科院分区：
文献类型：
--
作者：
H. Sugimura;Kazuyuki Hayashi;N. Saito;O. Takai;N. Nakagiri
用开尔文探针力显微镜(KFM)测量了有机硅烷自组装单分子膜(SAM)的表面电位差。自组装膜由十八烷基三甲氧基硅烷[H3C(CH2)17Si(OCH3)3]和氟烷基硅烷heptadecafluoro-1，1，2，2-tetrahydro-decyl-1-trimethoxysilane[F3C(CF2)7(CH2)2Si(OCH3)3]沉积在同一硅衬底上。通过光刻技术确定了这些自组装膜在衬底上的位置。在优化的成像条件下，KFM可以清楚地区分以ODS和Fas终止的区域，并利用两者之间的表面电势差来区分。Fas末端区域的表面电位比ODS末端区域的表面电位低170~180 mV。根据分子轨道计算，Fas-SAM的低表面电势归因于F原子的电子负性引起的Fas分子的较大偶极矩。
A difference in surface potentials between organosilane self-assembled monolayers (SAMs) was measured by means of Kelvin probe force microscopy (KFM). The SAMs were deposited on a single Si substrate from alkylsilane, that is, octadecyltrimethoxysilane (ODS) [H3C(CH2)17Si(OCH3)3], and fluoroalkylsilane (FAS), that is, heptadecafluoro-1,1,2,2-tetrahydro-decyl-1-trimethoxysilane [F3C(CF2)7(CH2)2Si(OCH3)3]. The locations of these SAMs on the substrate were defined by means of a photolithographic technique. The regions terminated with ODS and FAS were clearly distinguished by KFM with the surface potential difference between the ODS- and FAS-terminated surfaces under optimized imaging conditions. The surface potential of the FAS-terminated region was 170~180 mV lower than the potential of the ODS-terminated surface. The origin of such a low surface potential of FAS-SAM was ascribed to the larger dipole moment of the FAS molecule induced by the electron negativity of F atoms as estimated from a molecular orbital calculation.