Development of small AC voltage superimposed displacement current measurement for light-emitting electrochemical cell

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K17640
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Device related chemistry; Electron device/Electronic equipment
• Research Institution: Chiba University
• Principal Investigator: Tanaka Yuya 千葉大学, 先進科学センター, 助教 (90780065)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 電気化学発光セル / 変位電流評価法 / インピーダンス分光 / 電気二重層 / イオン液体 / モジュラス / 有機半導体 / 有機発光ダイオード

Outline of Final Research Achievements

To deeply understand operation mechanism of light-emitting electrochemical cells (LECs) and put them into practical use, evaluation of dynamics of carriers such as charges and ions is highly required. In this study, by combining displacement current measurement (DCM), which can observe carrier dynamics, and impedance spectroscopy (IS), which enables quantitative analysis of impedance (Z), we developed small AC voltage superimposed DCM (AC-DCM). The AC-DCM successfully separated Z in forward and reverse scans, and we found that Z in the forward scan is larger. These results suggest that AC-DCM is a powerful tool to observe the dynamics of carriers in LEC.

Free Research Field

有機半導体デバイス

Academic Significance and Societal Importance of the Research Achievements

電気化学発光セル（LEC）の動作機構を解明するためには，素子内の電荷やイオンといったキャリアの動的な挙動と，それに由来するインピーダンスを定量的に評価する必要がある．そこで本研究ではこれを可能にする新しい評価手法を提案した．その結果LECに印加する電圧を増加させた場合と減少させた場合とでは，キャリアの挙動が異なることを明らかにした．本手法は様々なデバイスに対しても有力な評価手法であるといえる．