Size-dependent tunneling and optical spectroscopy of InAs nanocrystal quantum dots

Journal Article · Wed Mar 01 00:00:00 EST 2000 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1023/A:1004642000900· OSTI ID:20023256

Millo, O; Katz, D; Levi, Y; Cao, Y W; Banin, U

Scanning tunneling spectroscopy is used to investigate single InAs nanocrystals, 2 to 8 nm in diameter. The tunneling current-voltage characteristics exhibit a pronounced size dependence of both single electron charging energy and quantum-confined electronic states. These are well described using the Orthodox Model for single electron tunneling through a quantum dot with a discrete level structure. Quantum confined states having atomic-like S and P symmetries are directly identified in the tunneling spectra as two and six-fold single electron charging multiplets, respectively. The tunneling spectra acquired on un-passivated nanocrystals show clear evidence of sub-gap-surface states. Surprisingly, excellent agreement is found between the strongly allowed optical transitions and spacing of levels detected in the tunneling experiment.

• Research Organization: Hebrew Univ., Jerusalem (IL)
• OSTI ID: 20023256
• Journal Information: Journal of Low Temperature Physics, Vol. 118, Issue 5-6; Conference: International Conference on Electron Transport in Mesoscopic Systems, Goeteborg (SE), 08/12/1999--08/15/1999; Other Information: PBD: Mar 2000; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
INDIUM ARSENIDES
SPECTROSCOPY
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
TUNNEL EFFECT
GRAIN SIZE