2007 Fiscal Year Final Research Report Summary
Fabrication of terahertz detectors based on InAs/AISb/AlGaSb/GaSb heterostructures
| Project/Area Number |
18560421
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Measurement engineering
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| Research Institution | Osaka Institute of Technology |
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Principal Investigator |
INOUE Masataka Osaka Institute of Technology, Faculty of Engineering, Professor (20029325)
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| Co-Investigator(Kenkyū-buntansha) |
SASA Shigehiko Osaka Institute of Technology, Faculty of Engineering, Professor (50278561)
MAEMOTO Toshihiko Osaka Institute of Technology, Faculty of Engineering, Associate Professor (80280072)
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| Project Period (FY) |
2006 – 2007
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| Keywords | terahertz / sub-terahertz / diode / heterostructure / InAs / AlGaSb / negative resistance / curvature / ballistic |
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| Research Abstract |
Fabrication and characterization of Sb-based diodes for the detecting terahertz waves are described. InAs/AISb/AIGaSb/GaSb heterostructures were grown on a semi-insulating GaAs substrate by molecular beam epitaxy. The purpose is to properly design the diode structure in order to improve the sensitivity, the curvature γ in the I-V characteristics at low voltages. We changed the Al composition, x of the Al_xGa_<1-x>Sb and thickness, y of the AlSb barrier. The maximum curvature y of 16.9^<-1> was obtained for the x=0.25 and the y=1.5nm.
Electron transport properties in InAs/AlGaSb three-terminal structures are also reported. This structure exhibited nonlinear electron transport properties from 4.2K to 300K because of ballistic properties of electrons. When dc input voltages are applied to the left and right branches in the push-pull fashion (V_L and V_R), the voltage measured at the central branch V_C showed obvious rectification properties with respect to V_L from 4.2K to 300K. In addition, current rectification effects in the current flow through the central branch were observed with the central branch being grounded and input voltages in push-pull fashion. These clear nonlinear effects indicate that the InAs/AlGaSb three-terminal device is one of the attractive future applications utilizing ballistic electron transport properties.
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