Synthesis of size-selected, surface-passivated InP nanocrystals

Journal Article · Thu Apr 25 04:00:00 EDT 1996 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/jp953719f· OSTI ID:249721

Guzelian, A A; Katari, J E.B.; Kadavanich, A V ^[1]

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1. Univ. of California, Berkeley, CA (United States)

Quantum-confined InP nanocrystals from 20 to 50 A in diameter have been synthesized via the reaction of InCl{sub 3} and P(Si(CH{sub 3}){sub 3}){sub 3} in trioctylphosphine oxide (TOPO) at elevated temperatures. The UV/vis absorption spectra of the particles show the characteristic blue shift of the band gap of up to 1 eV due to quantum confinement, a moderately well-resolved first excitonic excited state, and, in some cases, the resolution of a higher excited state. Structurally, the nanocrystals are characterized with powder X-ray diffraction and transmission electron microscopy. Raman spectroscopy reveals TO and LO modes near the characteristic bulk InP positions as well a surface mode resulting from finite size. The Raman line widths, line positions, and relative intensities are all size-dependent. X-ray photoelectron spectroscopy (XPS) shows the nanocrystals have a nearly stoichiometric ratio of indium to phosphorus with TOPO surface coverages ranging from 30% to 100%. Photoluminescence is observed as both band edge and deep trap emission with both features shifting with nanocrystal size. The luminescence is highly dependent on the surface of the nanocrystal with oxidation being a necessary condition for emission. 17 refs., 10 figs.

• OSTI ID: 249721
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 17 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ABSORPTION SPECTRA
CRYSTALS
EXCITED STATES
INDIUM PHOSPHIDES
OXIDATION
PASSIVATION
PHOTOLUMINESCENCE
RAMAN SPECTRA
SEMICONDUCTOR MATERIALS
STRUCTURAL CHEMICAL ANALYSIS
SURFACES
SYNTHESIS
ULTRAVIOLET SPECTRA
X-RAY DIFFRACTION