Title
Mixtures of Dopant-Free Spiro-OMeTAD and Water-Free PEDOT as a Passivating Hole Contact in Perovskite Solar Cells
Date Issued
06 March 2019
Access level
metadata only access
Resource Type
journal article
Author(s)
Kegelmann L.
Tockhorn P.
Wolff C.M.
Márquez J.A.
Caicedo-Dávila S.
Korte L.
Unold T.
Lövenich W.
Neher D.
Albrecht S.
Institute Silicon Photovoltaics
Publisher(s)
American Chemical Society
Abstract
Doped spiro-OMeTAD at present is the most commonly used hole transport material (HTM) in n-i-p-type perovskite solar cells, enabling high efficiencies around 22%. However, the required dopants were shown to induce nonradiative recombination of charge carriers and foster degradation of the solar cell. Here, in a novel approach, highly conductive and inexpensive water-free poly(3,4-ethylenedioxythiophene) (PEDOT) is used to replace these dopants. The resulting spiro-OMeTAD/PEDOT (SpiDOT) mixed films achieve higher lateral conductivities than layers of doped spiro-OMeTAD. Furthermore, combined transient and steady-state photoluminescence studies reveal a passivating effect of PEDOT, suppressing nonradiative recombination losses at the perovskite/HTM interface. This enables excellent quasi-Fermi level splitting values of up to 1.24 eV in perovskite/SpiDOT layer stacks and high open-circuit voltages (V OC ) up to 1.19 V in complete solar cells. Increasing the amount of dopant-free spiro-OMeTAD in SpiDOT layers is shown to enhance hole extraction and thereby improves the fill factor in solar cells. As a consequence, stabilized efficiencies up to 18.7% are realized, exceeding cells with doped spiro-OMeTAD as a HTM in this study. Moreover, to the best of our knowledge, these results mark the lowest nonradiative recombination loss in the V OC (140 mV with respect to the Shockley-Queisser limit) and highest efficiency reported so far for perovskite solar cells using PEDOT as a HTM.
Start page
9172
End page
9181
Volume
11
Issue
9
Language
English
OCDE Knowledge area
Ingeniería de materiales
Subjects
Scopus EID
2-s2.0-85062594052
PubMed ID
Source
ACS Applied Materials and Interfaces
ISSN of the container
19448244
Sponsor(s)
The authors would like to thank Hereaus for providing PEDOT formulations, Dr. Janardan Dagar, Dr. Mathias Mews, Dr. Sergej Levcenco, Carola Klimm, Carola Ferber, Monika Gabernig, and Heinz Hagen from Helmholtz-Zentrum Berlin for technical assistance and acknowledge financial support from the HyPerCell (Hybrid Perovskite Solar Cells, www. perovskites.de) joint Graduate School, as well as from the German Federal Ministry for Economic Affairs and Energy (BMWi) through the “PersiST” project (grant no. 0324037C). Further funding was provided by the Federal Ministry of Education and Research (BMBF) for funding of the Young Investigator Group Perovskite Tandem Solar Cells within the program “Materialforschung für die Energiewende” (grant no.
Helmholtz-Zentrum für Umweltforschung - UFZ
Helmholtz Association
Sources of information:
Directorio de Producción Científica
Scopus