Bandgap Engineering of InP QDs Through Shell Thickness and Composition

Conference · Thu Jun 21 04:00:00 EDT 2012

OSTI ID:1044830

Dennis, Allison M ^[1]; Mangum, Benjamin D ^[1]; Piryatinski, Andrei ^[1]; Park, Young-Shin ^[1]; Htoon, Han ^[1]; Hollingsworth, Jennifer A ^[1]

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1. Los Alamos National Laboratory

Fields as diverse as biological imaging and telecommunications utilize the unique photophysical and electronic properties of nanocrystal quantum dots (NQDs). The development of new NQD compositions promises material properties optimized for specific applications, while addressing material toxicity. Indium phosphide (InP) offers a 'green' alternative to the traditional cadmium-based NQDs, but suffers from extreme susceptibility to oxidation. Coating InP cores with more stable shell materials significantly improves nanocrystal resistance to oxidation and photostability. We have investigated several new InP-based core-shell compositions, correlating our results with theoretical predictions of their optical and electronic properties. Specifically, we can tailor the InP core-shell QDs to a type-I, quasi-type-II, or type-II bandgap structure with emission wavelengths ranging from 500-1300 nm depending on the shell material used (ZnS, ZnSe, CdS, or CdSe) and the thickness of the shell. Single molecule microscopy assessments of photobleaching and blinking are used to correlate NQD properties with shell thickness.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: LDRD
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1044830
• Report Number(s): LA-UR-12-22430
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
77 NANOSCIENCE AND NANOTECHNOLOGY
COATINGS
INDIUM PHOSPHIDES
MICROSCOPY
OXIDATION
QUANTUM DOTS
THICKNESS
TOXICITY
WAVELENGTHS