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Step structure control of Molecular ciystals and Multiplication-type Photosensing devices

Research Project

Project/Area Number 14550009
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Applied materials science/Crystal engineering
Research InstitutionOsaka University

Principal Investigator

HIRARNOTO Masahiro  Osaka Univ., Grad.School.Eng, Associate Professor, 大学院・工学研究科, 助教授 (20208854)

Co-Investigator(Kenkyū-buntansha) YOKOYAMA Masaaki  Osaka Univ., Grad.School.Eng., Professor, 大学院・工学研究科, 教授 (90029281)
Project Period (FY) 2002 – 2003
Project Status Completed (Fiscal Year 2003)
Budget Amount *help
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2002: ¥2,700,000 (Direct Cost: ¥2,700,000)
KeywordsPhotocurrent Multiplication / Molecular Blind Alley / Molecular Crystals / Molecular Step / Kink Structure / Organic / Metal Interface / Structural Trap / Epitaxial Growth / 高速応答増倍デバイス / 構造ストラップ / エピ成長
Research Abstract

We have observed the large photocurrent multiplication phenomenon reaching 10^5-fold at metal/organic interface. Multiplication mechanism is the tunneling injection of electrons from metal electrode to organic layer triggered by the accumulation of photogenerated holes captured by the interfacial structural trap, namely, blind alleys at imperfect organic/metal contact which capture holes under the concentrated electric field toward metal.
Spatial gaps at metal/organic interface providing the hole capturing area, which is formed due to the partial contact of metal nanospheres to organic surface, were confirmed to exist.
Molecular steps on the organic crystal surface were revealed to act as blind alleys (molecular blind alley, MBA). As expected, single crystal surface having little molecular steps hardly showed multiplication. Moreover, multiplication rate increased with the number of MBA trap sites, i.e., the number of kinks in steps. Intentional fabrication of steps by epitaxial growth on the molecular-level flat crystal surface was confirmed to arise multiplication.
Both molecular blind alleys and spatial gaps are indispensable to cause photocurrent multiplication. Design of step structure at crystal surface would be an effective way to control the carrier injection to organic semiconductors.
High-speed photocurrent multiplication devices using co-deposited films of copper phthalocyanine and fullerene were fabricated. Photoresponse time for light on and off reached 3 and 15 ins, respectively, which were in striking contrast to those for single fullerene films requiring several seconds. Performance of the present device is promising for the application to multiplication-type photodetector.

Report

(3 results)
  • 2003 Annual Research Report   Final Research Report Summary
  • 2002 Annual Research Report
  • Research Products

    (27 results)

All Other

All Publications (27 results)

  • [Publications] Masahiro Hiramoto: "Metal Nanostructure of Metal/Organic Interface Causing Photocurrent Multiplication Phenomenon"IEICE Transactions on Electronics. E85-C(6). 1253-1255 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Goh Matsunobu: "High-speed Multiplication-type Photodetecting Device Using Organic Co-deposited Films"Appl.Phys.Lett.. 81(7). 1321-1322 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto: "Photocurrent Multiplication in Organic Single Crystals"Appl.Phys.Lett.. 81(8). 1500-1502 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto: "Photovoltaic Properties of Ultramicrostructure-Controlled Organic Codeposited Films"Jpn.J.Appl.Phys.. 41. 2763-2766 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto: "Influence of Oxygen and Water on Photocurrent Multiplication in Organic Semiconductor Films"Jpn.J.Appl.Phys.. 42(2A). 672-675 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto: "Influence of Oxygen on Photocurrent Multiplication Phenomenon at Organic/Metal Interface"Jpn.J.Appl.Phys.. 42(4B). 2495-2497 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto: ""Recent Research Developments in Applied Physics (6th issue)" published by Transworld Research Network (Kerala, India)"Nanostructure of Organic/Metal Interface and Photocurrent Multiplication Phenomenon. 25 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto, Ichiro Sato, Masaaki Yakoyama: "Metal Nanostructure of Metal/Organic Interface Causing Photocurrent Multiplication Phenomenon"IEICE Transactions on Electronics. E85-C(6). 1253-1255 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Goh Matsunobu, Yuko Oishi, Masaaki Yokoyama, Masahiro Hiramoto: "High-speed Multiplication-type Photodetecting Device Using Organic Co-deposited Films"Appl.Phys.Lett.. 81(7). 1321-1322 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto, Ayako Miki, Manabu Yoshida, Masaaki Yokoyama: "Photocurrent Multiplication in Organic Single Crystals"Appl.Phys.Lett.. 81(8). 1500-1502 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto, Kouji Suemori, Masaaki Yokoyama: "Photovoltaic Properties of Ultramicrostructure-Controlled Organic Co-deposited Films"Jpn.J.Appl.Phys.. 41. 2763-2766 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto, Kentaro Fujino, Manabu Yoshida, Masaaki Yokoyama: "Influence of Oxygen and Water on Photocurrent Multiplication in Organic Semiconductor Films"Jpn.J.Appl.Phys.. 42(No.2A). 672-675 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto, Kouji Suemori, Masaaki Yokoyama: "Influence of Oxygen on Photocurrent Multiplication Phenomenon at Organic/Metal Interface"Jpn.J.Appl.Phys.. 42(No.4B). 2495-2497 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Masahiro Hiramoto: "Nanostructure of Organic/Metal Interface and Phot6current Multiplication Phenomenon"In the book "Recent Research Developments in Applied Physics (6th issue)"(published by Transworld Research Network (Kerala, India)). 55-79 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] M.Hiramoto: "Metal nanostructure of metal/ organic interface causing photocurrent multiplication phenomenon"IEICE Trans. on Electronics. E85-C(6). 1253-1255 (2002)

    • Related Report
      2003 Annual Research Report
  • [Publications] G.Matsunobu: "High-speed Multiplication-type Photodetecting Device Using Organic Co-deposited Films"Applied Physics Letters. 81(7). 1321-1322 (2002)

    • Related Report
      2003 Annual Research Report
  • [Publications] M.Hiramoto: "Photocurrent Multiplication in Organic Single Crystals"Applied Physics Letters. 81(8). 1500-1502 (2002)

    • Related Report
      2003 Annual Research Report
  • [Publications] M.Hiramoto: "Influence of Oxygen and Water on Photocurrent Multiplication in Organic Semiconductor Films"Jpn.J.Appl.Phys.. 42(2A). 672-675 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] M.Hiramoto: "Influence of Oxygen on Photocurrent Multiplication Phenomenon at Organic/Metal Interface"Jpn.J.Appl.Phys.. 42(4B). 2495-2497 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] K.Suemori: "Crystalline-Amorphous Organic Co-deposited Films Slowing Efficient Photo-Electric Conversion"Molecular Crystals Liquid Crystals. April (in press). (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] M.Hiramoto: "Resent Research Developments in Applied Physics 5th issue Published by Transworld Research Network"Nanostructure of Organic/Metal Interface and Photocurrent Multiplication Phenomenon. 25 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] M.Hiramoto: "Metal Nanostructure of Metal/Organic Interface Causing Photocurrent Multiplication Phenomenon"IEICE Transactions on Electronics. E85-C(6). 1253-1255 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] G.Matsunobu: "High-speed Multiplication-type Photo detecting Device Using Organic Co-deposited Films"Applied Physics Letters. 81(7). 1321-1322 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Hiramoto: "Photocurrent Multiplication in Organic Single Crystals"Applied Physics Letters. 81(8). 1500-1502 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Hiramoto: "Influence of Oxygen and Water on Photo-current Multiplication in Organic Semiconductor Films"Japanese Journal of Applied Physics. 42(2A). 672-675 (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Hiramoto: "Influence of Oxygen on Photocurrent Multiplitcation at Organic/Metal Interface"Japanese Journal of Applied Physics. 42(4B)(in press). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Hiramoto: "Recent Research Developments in Applied Physics, 5th issue published by Tronsworld Research Network"Nanostructure of Organic/Metal Interface and Photocurrent Multiplication Phenomenon. 25 (2003)

    • Related Report
      2002 Annual Research Report

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Published: 2002-04-01   Modified: 2016-04-21  

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