Hokkaido University · 재료과학
Toshihiro Shimada 교수의 연구실은 고체물리 및 표면과학을 기반으로 한 이종재료의 에피택시성 성장과 계면 상호작용을 중심으로 연구를 진행하고 있습니다. 주로 산화물, 텅스텐 디 chalcogenide, 유기 반도체 등 다양한 계면에서의 전자 구조와 일관성 있는 나노구조 형성 메커니즘을 탐구하며, 고해상도 전자 회절 및 광전자 분광법을 활용한 정밀 분석을 수행합니다. 특히, 반도체-유기계면에서의 인터페이스 디폴, 전자 이완 및 결정성 제어에 초점을 맞추고 있습니다. 이는 나노전자소자 및 유기 반도체 장치의 고성능화에 기여하는 핵심 기초 연구입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Work functions and photothreshold values of various layered metal dichalcogenides ( ZrSe 2 , HfSe 2 , NbSe 2 , 1T-TaS 2 , 2H-TaS 2 , MoS 2 , MoSe 2 , α-MoTe 2 , SnS 2 , SnSe 2 ) have been measured by a photoemission technique. The measured photothreshold values, except for Sn compounds, are compared with the calculated values based on various band models. The agreement between the observed and calculated values is satisfactory for most of the materials.
New sources of selenium and sulfur for UHV preparation of thin films are described. These sources, utilizing the high temperature thermal decomposition of SnSe2 and SnS2, are bakeable to at least 300 °C providing much more convenience than element Se and S sources. The thermal decomposition is studied with thermal gravitometry, mass spectrometry, and x-ray photoemission spectroscopy. The utility of the sources is demonstrated by the epitaxial growth of TiSe2 on MoS2.
Copper phtalocyanine (CuPc) films with the thickness controlled in molecular scales have been grown epitaxially on (0001) surfaces of layered materials, and electronic interaction at the interfaces have been studied by photoelectron spectroscopy. Materials with different electronic properties having different work functions (Evac) were chosen as the substrates; semiconducting MoTe2 (Evac=4.0 eV), semi-metallic highly oriented pyrolytic graphite (Evac=4.5 eV) and metallic TaSe2 (Evac=5.5 eV). For
Hydrogen-terminated vicinal Si(111) surfaces provide quasi-van der Waals substrates with regularly spaced atomic height steps for the epitaxy of organic material films. Molecular beam epitaxy of vanadyl and copper phthalocyanines (VOPc and CuPc) was attempted on just-cut and 7°-miscut surfaces in order to investigate the effect of the steps on the epitaxial growth feature. The molecular arrangement of the films was characterized by a new technique using multiple-azimuth reflection high energy el
The epitaxial growth of pentacene on hydrogen-terminated Si(111) is reported. Reflection high energy electron diffraction (RHEED) revealed that the crystal packing resembles that in the bulk crystal even at a monolayer thickness, which was maintained in multilayers. A ripening effect was clearly observed by atomic force microscopy (AFM). These results are important to obtain oriented crystalline films of pentacene combined with silicon microdevices with reduced defect densities.
