Reduced Nonradiative Voltage Loss in Terpolymer Solar CellsShow others and affiliations
2020 (English)In: The Journal of Physical Chemistry Letters, E-ISSN 1948-7185, Vol. 11, no 10, p. 3796-3802Article in journal (Refereed) Published
Abstract [en]
The dissociation of hybrid local exciton and charge transfer excitons (LECT) in efficient bulk-heterojunction nonfullerene solar cells contributes to reduced nonradiative photovoltage loss, a mechanism that still remains unclear. Herein we studied the energetic and entropic contribution in the hybrid LE-CT exciton dissociation in devices based on a conjugated terpolymer. Compared with reference devices based on ternary blends, the terpolymer devices demonstrated a significant reduction in the nonradiative photovoltage loss, regardless of the acceptor molecule, be it fullerene or nonfullerene. Fourier transform photocurrent spectroscopy revealed a significant LE-CT character in the terpolymer-based solar cells. Temperature-dependent hole mobility and photovoltage confirm that entropic and energetic effects contribute to the efficient LE-CT dissociation. The energetic disorder value measured in the fullerene- or nonfullerene-based terpolymer devices suggested that this entropic contribution came from the terpolymer, a signature of higher disorder in copolymers with multiple aromatic groups. This gives new insight into the fundamental physics of efficient LE-CT exciton dissociation with smaller nonradiative recombination loss.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2020. Vol. 11, no 10, p. 3796-3802
National Category
Condensed Matter Physics
Identifiers
URN: urn:nbn:se:liu:diva-166853DOI: 10.1021/acs.jpclett.0c00915ISI: 000537432500007PubMedID: 32338006Scopus ID: 2-s2.0-85085263563OAI: oai:DiVA.org:liu-166853DiVA, id: diva2:1444638
Note
Funding Agencies|Knut and Alice Wallenberg Foundation (KAW) through a Wallenberg Scholar grant; China Scholarship Council (CSC)China Scholarship Council [201508320244]; International Science Programme (ISP), Uppsala University, Sweden
2020-06-222020-06-222024-07-04Bibliographically approved