Improved Height Measurement of Single CdSe Colloidal Quantum Dots by Contact-Mode Atomic Force Microscopy Using Carbon Nano-Tube Tips; for the Investigation of Current-Voltage Characteristics

• Tanaka Ichiro

  Department of Materials Science and Chemistry, Wakayama University

• Kajimoto Kaori

  Department of Materials Science and Chemistry, Wakayama University

• Uno Kazuyuki

  Department of Materials Science and Chemistry, Wakayama University

• Ohtsuki Osamu

  Department of Materials Science and Chemistry, Wakayama University

• Murase Tomohide

  Mitsubishi Chemical Group Science and Technology Research Center

• Asami Harumi

  Mitsubishi Chemical Group Science and Technology Research Center

• Hara Masahiko

  Department of Electronic Chemistry, Tokyo Institute of Technology

• Kamiya Itaru

  Toyota Technological Institute

Abstract

We have investigated the distribution of measured heights of single CdSe colloidal quantum dots (QDs) by contact-mode atomic force microscopy. The dot heights measured with metal-coated Si tips, with which large adhesive force is measured between the tip and sample, are much smaller than that expected from optical absorption. This discrepancy could be due to the dot position fluctuation that occurs when the tip is in contact with the dot because the height distribution of the QDs covered with very thin SiO₂ layer is in agreement with the optical measurement. On the other hand, when conductive carbon nano-tube (CNT) tips are used, the adhesive force is reduced significantly, and the measured dot heights become close to the expected value. Thus, the measurement of QD height is greatly improved in accuracy with CNT tips. As a result, the current flowing through the QD can be measured, and conductance changes attributed to electron resonant tunneling through the QD are observed.

Journal

• Japanese Journal of Applied Physics

  Japanese Journal of Applied Physics 44 (1-7), L249-L252, 2005

  The Japan Society of Applied Physics

Keywords

• colloidal dot
• quantum dot
• nano-crystal
• CdSe
• atomic force microscopy
• carbon nano-tube
• resonant tunneling

Details

• CRID: 1390001206266196224
• NII Article ID: 210000059477
• NII Article ID: 10014421153
• NII Book ID: AA11906093
• DOI: 10.1143/jjap.44.l249
• ISSN: 13474065
• ISSN: 00214922
• NDL BIB ID: 7257841
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7257841
• Web Site: https://iopscience.iop.org/article/10.1143/JJAP.44.L249
• Web Site: https://iopscience.iop.org/article/10.1143/JJAP.44.L249/pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed