Photocurrent imaging of nanocrystal quantum dots on single-walled carbon nanotube device

Won Seok Chang, Sohee Jeong, Hung Chul Shim, Chang-Soo Han, Jaegu Park, Young Hwan Ahn, Mun Seok Jeong

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Semiconductor nanocrystal quantum dots (NQDs) are considered an attractive candidate for use in optoelectronic applications due to the ease of band gap control provided by varying the particle size. To increase the efficiency of NQDs when practically applied in devices, researchers have introduced the concept of coupling of NQDs to one-dimensional nanostructures such as single-walled carbon nanotubes (SWCNTs), which have a ballistic conducting channel. In the present study, NQDs of CdSe core and CdSe/ZnS are used as light absorbing building blocks. SWCNTs and functionalized NQDs are non-covalently coupled using pyridine molecules in order to maintain their electronic structures. To measure the electrical signals from the device, a NQDs-SWCNT hybrid nanostructure is fabricated as a field-effect transistor (FET) using the dielectrophoresis (DEP) method. A confocal scanning microscope was used to scan the devices using a diffraction-limited laser spot and the photocurrent was recorded as a function of the position of the laser spot. To improve the performance of detecting small electronic signal with high signal-to-noise ratio we used a lock-in technique with an intensity-modulated laser. In this paper, we have demonstrated that detection of local photoconductivity provides an efficient means to resolve electronic structure modulations along NQDs-SWCNT hybrid nanostructures.

Original languageEnglish
Pages (from-to)4300-4304
Number of pages5
JournalJournal of Nanoscience and Nanotechnology
Volume11
Issue number5
DOIs
Publication statusPublished - 2011 May 1
Externally publishedYes

Fingerprint

Quantum Dots
Carbon Nanotubes
Single-walled carbon nanotubes (SWCN)
Photocurrents
Nanoparticles
Nanocrystals
Semiconductor quantum dots
photocurrents
nanocrystals
carbon nanotubes
quantum dots
Imaging techniques
Equipment and Supplies
Nanostructures
Lasers
Electronic structure
electronic structure
lasers
Photoconductivity
Ballistics

Keywords

  • Hybrid nanostructure
  • Nanocrystal quantum dots (NQDs)
  • Photocurrent imaging
  • Single-walled carbon nanotubes (SWCNTS)

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Chemistry(all)
  • Materials Science(all)
  • Bioengineering
  • Biomedical Engineering

Cite this

Photocurrent imaging of nanocrystal quantum dots on single-walled carbon nanotube device. / Chang, Won Seok; Jeong, Sohee; Shim, Hung Chul; Han, Chang-Soo; Park, Jaegu; Ahn, Young Hwan; Jeong, Mun Seok.

In: Journal of Nanoscience and Nanotechnology, Vol. 11, No. 5, 01.05.2011, p. 4300-4304.

Research output: Contribution to journalArticle

Chang, Won Seok ; Jeong, Sohee ; Shim, Hung Chul ; Han, Chang-Soo ; Park, Jaegu ; Ahn, Young Hwan ; Jeong, Mun Seok. / Photocurrent imaging of nanocrystal quantum dots on single-walled carbon nanotube device. In: Journal of Nanoscience and Nanotechnology. 2011 ; Vol. 11, No. 5. pp. 4300-4304.
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