skip to main content


Title: Doped Interlayers for Improved Selectivity in Bulk Herterojunction Organic Photovoltaic Devices

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is less selective for holes in inverted-architecture organic photovoltaic (OPV) than it is in a conventional-architecture OPV device due differences between the interfacial-PSS concentration at the top and bottom of the PEDOT:PSS layer. In this work, thin layers of polysulfonic acids are inserted between the P3HT:ICBA bulk heterojunction (BHJ) active layer and PEDOT:PSS to create a higher concentration of acid at this interface and, therefore, mimic the distribution of materials present in a conventional device. Upon thermal annealing, this acid layer oxidizes P3HT, creating a thin p-type interlayer of P3HT+/acid- on top of the BHJ. Using x-ray absorption spectroscopy, Kelvin probe and ellipsometry measurements, this P3HT+/acid- layer is shown to be insoluble in water, indicating it remains intact during the subsequent deposition of PEDOT:PSS. Current density - voltage measurements show this doped interlayer reduces injected dark current while increasing both open-circuit voltage and fill factor through the creation of a more hole selective BHJ-PEDOT:PSS interface.
 [1] ;  [2] ;  [1] ;  [3] ;  [3] ;  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States). Chemistry and Nanoscience Center
  2. Colorado School of Mines, Golden, CO (United States)
  3. Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry
Publication Date:
Report Number(s):
Journal ID: ISSN 2196-7350
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Advanced Materials Interfaces
Additional Journal Information:
Journal Volume: 3; Journal Issue: 2; Journal ID: ISSN 2196-7350
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Country of Publication:
United States
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; charge selectivity; doping; interlayers; organic photovoltaics
OSTI Identifier: