Direct correlation of nanoscale morphology and device performance to study photocurrent generation in donor enriched phases of polymer solar cells

Autor: Uli Würfel, Martin Pfannmöller, Sadok Ben Dkhil, Yatzil Alejandra Avalos Quiroz, Riva Alkarsifi, Sara Bals, Elena Barulina, David Müller, Christine Videlot-Ackermann, Olivier Margeat, Stephan Thierry Dubas, Claudia Caddeo, Pavlo Perkhun, Alessandro Mattoni, Jörg Ackermann, Noriyuki Yoshimoto, Tomoyuki Koganezawa, Birger Zimmermann, Daiki Kuzuhara, Chieh Luo
Přispěvatelé: Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE), Fraunhofer (Fraunhofer-Gesellschaft), University of Antwerp (UA), European Project: 713750,H2020,H2020-MSCA-COFUND-2015,DOC2AMU(2016), Publica, ANR-17-CE05-0020,NFA-15,Cellules solaires organiques à base d'accepteur non fullerène avec un rendement de 15% et une durée de vie de 10 ans(2017)
Rok vydání: 2020
Předmět:
Zdroj: ACS Applied Materials & Interfaces
ACS Applied Materials & Interfaces, Washington, D.C. : American Chemical Society, 2020, ⟨10.1021/acsami.0c05884⟩
ACS Applied Materials & Interfaces, 2020, ⟨10.1021/acsami.0c05884⟩
ACS applied materials & interfaces
12 (2020): 28404–28415. doi:10.1021/acsami.0c05884
info:cnr-pdr/source/autori:Ben Dkhil, Sadok; Perkhun, Pavlo; Luo, Chieh; Mueller, David; Alkarsifi, Riva; Barulina, Elena; Quiroz, Yatzil Alejandra Avalos; Margeat, Olivier; Dubas, Stephan Thierry; Koganezawa, Tomoyuki; Kuzuhara, Daiki; Yoshimoto, Noriyuki; Caddeo, Claudia; Mattoni, Alessandro; Zimmermann, Birger; Wuerfel, Uli; Pfannmoeller, Martin; Bals, Sara; Ackermann, Joerg; Videlot-Ackermann, Christine/titolo:Direct Correlation of Nanoscale Morphology and Device Performance to Study Photocurrent Generation in Donor-Enriched Phases of Polymer Solar Cells/doi:10.1021%2Facsami.0c05884/rivista:ACS applied materials & interfaces (Print)/anno:2020/pagina_da:28404/pagina_a:28415/intervallo_pagine:28404–28415/volume:12
ACS applied materials and interfaces
ISSN: 1944-8244
1944-8252
DOI: 10.1021/acsami.0c05884
Popis: The nanoscale morphology of polymer blends is a key parameter to reach high efficiency in bulk heterojunction solar cells. Thereby, research typically focusing on optimal blend morphologies while studying nonoptimized blends may give insight into blend designs that can prove more robust against morphology defects. Here, we focus on the direct correlation of morphology and device performance of thieno[3,4-b]-thiophene-alt-benzodithiophene (PTB7):[6,6]phenyl C-71 butyric acid methyl ester (PC71BM) bulk heterojunction (BHJ) blends processed without additives in different donor/acceptor weight ratios. We show that while blends of a 1:1.5 ratio are composed of large donor-enriched and fullerene domains beyond the exciton diffusion length, reducing the ratio below 1:0.5 leads to blends composed purely of polymer-enriched domains. Importantly, the photocurrent density in such blends can reach values between 45 and 60% of those reached for fully optimized blends using additives. We provide here direct visual evidence that fullerenes in the donor-enriched domains are not distributed homogeneously but fluctuate locally. To this end, we performed compositional nanoscale morphology analysis of the blend using spectroscopic imaging of low-energy-loss electrons using a transmission electron microscope. Charge transport measurement in combination with molecular dynamics simulations shows that the fullerene substructures inside the polymer phase generate efficient electron transport in the polymer-enriched phase. Furthermore, we show that the formation of densely packed regions of fullerene inside the polymer phase is driven by the PTB7:PC71BM enthalpy of mixing. The occurrence of such a nanoscale network of fullerene clusters leads to a reduction of electron trap states and thus efficient extraction of photocurrent inside the polymer domain. Suitable tuning of the polymer-acceptor interaction can thus introduce acceptor subnetworks in polymer-enriched phases, improving the tolerance for high-efficiency BHJ toward morphological defects such as donor-enriched domains exceeding the exciton diffusion length.
Databáze: OpenAIRE
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