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Title: Charge-transfer dynamics in multilayered PbS and PbSe quantum dot architectures

We demonstrate control of the charge transfer process in PbS and PbSe quantum dot assemblies. We first demonstrate efficient charge transfer from donor quantum dots to acceptor quantum dots in a multi-layer PbSe cascade structure. Then, we assemble type-I and type-II heterostructures using both PbS and PbSe quantum dots via careful control of the band alignment. In type-I structures, photo-generated carriers are transferred and localized in the smaller bandgap (acceptor) quantum dots, resulting in a significant luminescence enhancement. In contrast, a significant luminescence quenching and shorter emission lifetime confirms an efficient separation of photo-generated carriers in the type-II architecture.
Authors:
;  [1] ; ;  [2] ;  [1] ;  [3]
  1. Department of Electrical and Computer Engineering, University of Delaware, 140 Evans Hall, Newark, Delaware 19716 (United States)
  2. Department of Materials Science and Engineering, University of Delaware, 201 DuPont Hall, Newark, Delaware 19716 (United States)
  3. (Canada)
Publication Date:
OSTI Identifier:
22283249
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; CHARGE CARRIERS; LAYERS; LEAD SELENIDES; LEAD SULFIDES; LIFETIME; LUMINESCENCE; QUANTUM DOTS; QUENCHING