title: Mapping the spatial distribution of charge carriers in quantum-confined heterostructures.
abstract: Quantum-confined nanostructures are considered 'artificial atoms' because the wavefunctions of their charge carriers resemble those of atomic orbitals. For multiple-domain heterostructures, however, carrier wavefunctions are more complex and still not well understood. We have prepared a unique series of cation-exchanged Hg(x)Cd(1-x)Te quantum dots (QDs) and seven epitaxial core-shell QDs and measured their first and second exciton peak oscillator strengths as a function of size and chemical composition. A major finding is that carrier locations can be quantitatively mapped and visualized during shell growth or cation exchange simply using absorption transition strengths. These results reveal that a broad range of quantum heterostructures with different internal structures and band alignments exhibit distinct carrier localization patterns that can be used to further improve the performance of optoelectronic devices and enhance the brightness of QD probes for bioimaging.
authors: 1] Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Health Sciences Research Building, Room E116, 1760 Haygood Drive, Atlanta, Georgia 30322, USA [2] Micro and Nanotechnology Laboratory, Department of Bioengineering, University of Illinois at Urbana-Champaign, Room 3114, 208 North Wright Street, Urbana, Illinois 61801, USA.
authors: Andrew M
authors: AM
authors: Smith
authors: Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Health Sciences Research Building, Room E116, 1760 Haygood Drive, Atlanta, Georgia 30322, USA.
authors: Lucas A
authors: LA
authors: Lane
authors: 1] Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Health Sciences Research Building, Room E116, 1760 Haygood Drive, Atlanta, Georgia 30322, USA [2] College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing, Jiangsu Province 210093, China.
authors: Shuming
authors: S
authors: Nie
mesh_terms: D002104:Cadmium / Q000737:chemistry*; D008628:Mercury / Q000737:chemistry*; D057054:Molecular Imaging / Q000379:methods; D049329:Nanostructures / Q000737:chemistry*; D055096:Optical Devices; D010316:Particle Size; D045663:Quantum Dots / Q000737:chemistry*; D055672:Static Electricity; D013691:Tellurium / Q000737:chemistry*
chemical_list: D002104:Cadmium; D008628:Mercury; D013691:Tellurium