Photo-induced carrier mapping by Kelvin force microscope under modulated light illuminationulated light

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04681
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26010:Metallic material properties-related
• Research Institution: Kyushu University
• Principal Investigator: Arita Makoto 九州大学, 工学研究院, 助教 (30284540)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: KFM / 光励起 / 薄膜 / 半導体

Outline of Final Research Achievements

A system that can visualize 2-dimensional mapping of photo-induced carriers in semiconductors have been developed. The system consists of a conventional Kelvin probe force microscope (KFM) equipped with a modulated monochromatic light source and a lock-in amplifier which extract a surface potential change induced by photo illumination.
Applying the system to TiO2 thin film with Au dots deposited on the surface, A photo response was observed at the exposed TiO2 surface when the illuminated photon energy was larger than the band gap energy of TiO2. The mapping of photo-induced surface potential change was successfully obtained by the system.

Free Research Field

薄膜・表面工学、　材料工学

Academic Significance and Societal Importance of the Research Achievements

本研究では、試料の測定部位付近への比較的広範囲の変調光照射機構を普及したKFM装置に組込むといった手法で、半導体材料におけるキャリアの光励起状態のマッピングを試みた。本研究により得られた成果は、走査型プローブ顕微鏡(PSM)への機能付与の試みとして、エネルギーや環境分野で求められる半導体デバイスのさらなる高性能化に貢献できるものと考えられる。