skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on December 17, 2016

Title: Visualization of Current and Mapping of Elements in Quantum Dot Solar Cells

The delicate influence of properties such as high surface state density and organic-inorganic boundaries on the individual quantum dot electronic structure complicates pursuits toward forming quantitative models of quantum dot thin films ab initio. Our report describes the application of electron beam-induced current (EBIC) microscopy to depleted-heterojunction colloidal quantum dot photovoltaics (DH-CQD PVs), a technique which affords one a map of current production within the active layer of a PV device. The effects of QD sample size polydispersity as well as layer thickness in CQD active layers as they pertain to current production within these PVs are imaged and explained. The results from these experiments compare well with previous estimations, and confirm the ability of EBIC to function as a valuable empirical tool for the design and betterment of DH-CQD PVs. Lastly, extensive and unexpected PbS QD penetration into the mesoporous TiO2 layer is observed through imaging of device cross sections by energy-dispersive X-ray spectroscopy combined with scanning transmission electron microscopy. Finally, the effects of this finding are discussed and corroborated with the EBIC studies on similar devices.
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [2] ;  [3]
  1. Vanderbilt Univ., Nashville, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Vanderbilt Univ., Nashville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
OSTI Identifier:
1261511
Grant/Contract Number:
AC05-00OR22725; EPS-1004083
Type:
Accepted Manuscript
Journal Name:
Advanced Functional Materials
Additional Journal Information:
Journal Volume: 26; Journal Issue: 6; Journal ID: ISSN 1616-301X
Publisher:
Wiley
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY EBIC; EDS elemental maps; photovoltaics; quantum dots; ELECTRON INJECTION; TIO2 ELECTRODES; PHOTOVOLTAICS; NANOPARTICLES; SEPARATION; SOLIDS