Transport in a Single Self-Doped Nanocrystal
Hongyue Wang1, Emmanuel Lhuillier2, Qian Yu1
1ESPCI-ParisTech, PSL Research University, UPMC Université Paris 06, LPEM, CNRS , 10 rue Vauquelin, Paris Cedex 5 F-75231, France.
ACS Nano
|January 4, 2017
Summary
Researchers developed a new method to characterize single nanoparticle conductance in the infrared. This technique revealed two energy gaps in HgSe nanoparticles, confirming their doped nature and enabling phototransport studies.
Area of Science:
- Condensed Matter Physics
- Nanotechnology
- Spectroscopy
Background:
- Characterizing single nanoparticles in the infrared is difficult.
- Existing methods for infrared optical properties are limited.
- Novel techniques are needed for nanoparticle spectroscopy.
Purpose of the Study:
- Develop an efficient method for fabricating single nanoparticle tunnel junctions.
- Characterize the conductance spectrum of narrow band gap nanoparticles (HgSe) in the infrared.
- Investigate the phototransport properties of single quantum dots.
Main Methods:
- Fabrication of single nanoparticle tunnel junctions on a chip circuit.
- Application of gate bias to tune energy levels.
- Measurement of conductance spectrum and phototransport.
Main Results:
- Successfully fabricated single nanoparticle tunnel junctions.
- Observed two distinct energy gaps in HgSe nanoparticles: a wider interband gap and a narrower intraband gap.
- Confirmed the doped character of nanoparticles at the single-particle level.
- Demonstrated a photogain mechanism in single quantum dots via photogating.
Conclusions:
- The developed method efficiently characterizes nanoparticle conductance in the infrared.
- The results provide single-particle level confirmation of nanoparticle doping.
- The study opens avenues for exploring phototransport phenomena in quantum dots.
