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Molecular Oxygen Induced in-Gap States in PbS Quantum Dots
- Source :
- Zhang, Yingjie; Zherebetskyy, Danylo; Bronstein, Noah D.; Barja, Sara; Lichtenstein, Leonid; Alivisatos, A. Paul; et al.(2015). Molecular Oxygen Induced in-Gap States in PbS Quantum Dots. ACS Nano, 9(10). Lawrence Berkeley National Laboratory: Lawrence Berkeley National Laboratory. Retrieved from: http://www.escholarship.org/uc/item/2vj4d55n
- Publication Year :
- 2015
- Publisher :
- American Chemical Society (ACS), 2015.
-
Abstract
- Artificial solids composed of semiconductor quantum dots (QDs) are being developed for large-area electronic and optoelectronic applications, but these materials often have defect-induced in-gap states (IGS) of unknown chemical origin. Here we performed scanning probe based spectroscopic analysis and density functional theory calculations to determine the nature of such states and their electronic structure. We found that IGS near the valence band occur frequently in the QDs except when treated with reducing agents. Calculations on various possible defects and chemical spectroscopy revealed that molecular oxygen is most likely at the origin of these IGS. We expect this impurity-induced deep IGS to be a common occurrence in ionic semiconductors, where the intrinsic vacancy defects either do not produce IGS or produce shallow states near band edges. Ionic QDs with surface passivation to block impurity adsorption are thus ideal for high-efficiency optoelectronic device applications.
- Subjects :
- Materials science
business.industry
General Engineering
Analytical chemistry
General Physics and Astronomy
Ionic bonding
02 engineering and technology
Electronic structure
Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
010402 general chemistry
021001 nanoscience & nanotechnology
01 natural sciences
0104 chemical sciences
Condensed Matter::Materials Science
Semiconductor
Nanocrystal
Quantum dot
Chemical physics
Vacancy defect
General Materials Science
Density functional theory
0210 nano-technology
Spectroscopy
business
Subjects
Details
- ISSN :
- 1936086X and 19360851
- Volume :
- 9
- Database :
- OpenAIRE
- Journal :
- ACS Nano
- Accession number :
- edsair.doi.dedup.....832e85093a136b3915fe0711e07e6f27