Three-dimensional operando analysis of interfaces in organic semiconductor devices using synchrotron X-ray spectromicroscopy

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K17463
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: National Institute for Materials Science
• Principal Investigator: NAGAMURA Naoka 国立研究開発法人物質・材料研究機構, 先端材料解析研究拠点, 研究員 (40708799)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 有機電界効果トランジスタ / 量子ビーム / 顕微分光 / イメージング / ナノ電子デバイス / オペランド観測

Outline of Final Research Achievements

Organic field effect transistor (OFET) utilizing π-electron organic molecular semiconductor thin films as a channel have great advantage in flexibility and potential for molecular designing. In our research, we have clarified the microscopic electronic states in the vicinity of interfaces and defects in device structures, which affect the macroscopic transport characteristics, using a scanning photoelectron microscopy equipment with a operando measurement system, called “3D nano-ESCA”.
We confirmed that the pin-point core level peak shift of carbon 1s state reflects local chemical potential by simultaneous measurements of spectroscopy and transport characteristics of OFETs using thiophene derivative molecule "C10-DNBDT-NW". The potential mapping obtained by measuring the spatial change of the core level peak shift suggests the presence of the charge trapping at the metal electrode/organic molecular interface, and several domains with different mobilities.

Free Research Field

薄膜・表面界面物性