Influence of Substrate on In-Plane Electrical Conduction of CuPc Nano-Crystals
Influence of Substrate on In-Plane Electrical Conduction of CuPc Nano-Crystals
复制标题
基材对 CuPc 纳米晶面内导电的影响
DOI：
10.1557/proc-738-g8.11
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
K. Kudo
中科院分区：
文献类型：
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作者：
M. Nakamura;Masatoshi Watanabe;T. Maruyama;M. Iizuka;K. Kudo
研究了在二氧化硅和云母表面沉积的酞菁铜纳米晶体的电导率变化。通过x射线光电子能谱分析，SiO2表面羟基的密度是云母表面羟基密度的10倍以上。两种基质上生长的晶体均为α -型的c轴取向晶体。利用原子力显微镜的电流成像技术，对不同高度的晶粒进行了电导-距离（G-d）测量。得到的电导率与晶体高度的关系图表明，高度较低的晶体在两个表面上都具有较高的电导率。此外，SiO2上的低高度晶体比云母上的低高度晶体具有更高的电导率。这些结果表明，底部分子层中的电子被转移到底物表面的亲电官能团上。这种现象在有机半导体/绝缘体界面上首次报道。
We have investigated the conductivity variation of copper phthalocyanine nano-crystals deposited on SiO2 and mica. The density of surface hydroxyl group on SiO2 was estimated to be more than 10 times larger than that on mica by X-ray photoelectron spectroscopy. The grown crystals on both substrates were categorized to be c-axis orientation of α–form. Conductance-distance (G-d) measurements for various crystalline grains having different heights have been carried out with current imaging using atomic force microscope. The obtained conductivity vs. crystal height plot indicates that lower height crystals have higher conductivities on both surfaces. Besides, the lower height crystals on SiO2 have higher conductivity than those on mica. These results suggest that the electrons in the bottommost molecular layer are transferred to the electrophilic functional groups on the substrate surface. Such a phenomenon at organic semiconductor/insulator interface is reported for the first time.