Accumulated charge measurement using a substrate with a restricted-bottom-electrode structure
Accumulated charge measurement using a substrate with a restricted-bottom-electrode structure
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使用具有受限底部电极结构的基板进行累积电荷测量
DOI：
10.1016/j.orgel.2019.07.009
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发表时间：
2019
影响因子：
3.2
通讯作者：
Ikemoto Yuka
中科院分区：
文献类型：
--
作者：
Tanimura Toshiaki;Tajima Hiroyuki;Ogino Akinari;Miyamoto Yuta;Kadoya Tomofumi;Komino Takeshi;Yokomatsu Tokuji;Maenaka Kazusuke;Ikemoto Yuka
累积电荷测量（ACM）是一种利用金属-绝缘体-半导体-金属（MISM）电容器直接测量有机半导体材料界面电荷注入势垒的新实验技术。在该技术中，需要对绝缘体层（CI）的静电容量进行精确估计以用于分析。该参数的信息原则上包含在ACM数据中;然而，由于具有不受限制的电极结构的有机MISM电容器中的电荷扩散效应导致的误差，因此不直接评估该参数。因此，在以前的ACM实验中，CI已经从电极的面积独立地估计。在这项研究中，一种新颖的设计与限制底部电极结构的基板。使用新设计的基板，它是可能的，以抑制电荷扩散效应，并成功地估计精确值的CI直接从ACM数据。随后，可以评估在无金属酞菁（H2 Pc）-Ag和并五苯-Au界面处的注入势垒，其分别为0.4和0.15 eV。对于测量中使用的样品，还确定了半导体层中的内建电势。
Accumulated charge measurement (ACM) is a new experimental technique for organic semiconductors to evaluate the charge injection barrier at the semiconductor–metal interface directly using a metal–insulator–semiconductor–metal (MISM) capacitor. In this technique, the precise estimation of the electrostatic capacity of the insulator layer (CI) is required for the analysis. The information of this parameter is, in principle, included in the ACM data; however, it is not directly evaluated because of the error resulting from the charge-spreading effect in an organic MISM capacitor with an unrestricted electrode structure. Therefore, theCIin previous ACM experiments has been independently estimated from the area of the electrode. In this study, a novel design of a substrate with a restricted-bottom-electrode structure is reported. Using the newly designed substrate, it was possible to suppress the charge-spreading effect and successfully estimate precise values ofCIdirectly from the ACM data. Subsequently, it was possible to evaluate the injection barriers at the metal-free phthalocyanine (H2Pc)–Ag and pentacene–Au interfaces, which were 0.4 and 0.15 eV, respectively. The built-in potentials in the semiconductor layer were also determined for the samples used in the measurement.