Analysis of the charge behavior in organic device interfaces using nonlinear optical spectroscopy

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03885
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Device related chemistry
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Miyamae Takayuki 国立研究開発法人産業技術総合研究所, 材料・化学領域, 主任研究員 (80358134)
• Co-Investigator(Kenkyū-buntansha): 宮寺 哲彦 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 主任研究員 (30443039) ; 阿澄 玲子 国立研究開発法人産業技術総合研究所, エレクトロニクス・製造領域, 副研究部門長 (40356366)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 有機デバイス / 和周波発生 / 電荷輸送 / 表面・界面 / 非線形分光

Outline of Final Research Achievements

Time-resolved electric-field-induced sum-frequency generation (EFI-SFG) spectroscopy was employed to study the charge behavior of multilayer organic devices including organic light-emitting diodes (OLEDs). Through application of the square wave pulse bias to the OLEDs, compensation of the polarization charges in the electron transport layer, and the generation of the NPD cation was observed. When the pulse voltage was turned off, the NPD cation immediately disappeared, confirming that charge recombination occurs at the interfaces. We could therefore conclude that time-resolved EFI-SFG is a useful technique to probe the carrier behavior at the buried interfaces of organic devices as well as to identify the origin of the charge carriers in OLEDs, which are essentially inaccessible by other techniques.

Free Research Field

物性化学