title: Electrical Characteristics of the Junction between PEDOT:PSS and Thiophene-Functionalized Silicon Microwires.
abstract: Thiophene moieties have been attached to Si microwires (Si MWs) by a two-step chlorination/alkylation reaction method. X-ray photoelectron spectroscopy indicated that saturation of the surface occurred after 30 min of reaction time. Electrical measurements using a standard probe station indicated that the junction between individual thiophene-functionalized Si MWs and the conducting polymer poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (
  PSS) became more ohmic as more thiophene was added to the MW surface. Under a light-limited current of 20 nA, representative of operation of Si MWs under 1 Sun illumination conditions, the iR loss of thiophene-n-Si MW/PEDOT-PSS contacts was 20 mV, representing an order of magnitude reduction compared with PEDOT-PSS junctions formed with methyl terminated n-Si MWs. Such iR losses are much less than typical catalytic overpotentials for fuel formation, and hence the thiophene-functionalized Si MW contacts will not limit the performance of a Si MW array-based solar fuels device under 1 Sun illumination.
authors.affiliation: Department of Chemistry, University of Manitoba , Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Jared P
authors.initials: JP
authors.lastname: Bruce
authors.affiliation: Department of Electrical and Computer Engineering, University of Manitoba , Winnipeg, Manitoba R3T 5V6, Canada.
authors.forename: Derek R
authors.initials: DR
authors.lastname: Oliver
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Lewis
authors.affiliation: Department of Chemistry, University of Manitoba , Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Freund
keywords: PEDOT:PSS; artificial photosynthesis; electrical characteristics; microwires; silicon; surface functionalization