Terahertz emission from graphene/semicnductor junctions and its application to gas sensors

2014 Fiscal Year Final Research Report

• Project/Area Number: 25630149
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Electron device/Electronic equipment
• Research Institution: Osaka University
• Principal Investigator: TONOUCHI MASAYOSHI 大阪大学, レーザーエネルギー学研究センタ, 教授 (40207593)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: グラフェン / テラヘルツ / 表面反応

Outline of Final Research Achievements

We demonstrate a new approach to visualize the distribution of molecular adsorbates on graphene using terahertz emission spectroscopy and imaging. We found that the waveforms of terahertz radiation from graphene-coated InP sensitively changed with the type of the atmospheric gas, the laser illumination time. The terahertz waveform change is explained through band structure modifications in the InP surface depletion layer due to the presence of localized electric dipoles induced by adsorbed oxygen. These results demonstrate that terahertz emission serves as a local probe for monitoring adsorption and desorption processes on graphene films and devices, suggesting a novel two-dimensional sensor for detecting local chemical reactions.

Free Research Field

テラヘルツ工学