Reduced Nonradiative Voltage Loss in Terpolymer Solar Cells
Artikel i vetenskaplig tidskrift, 2020

The dissociation of hybrid local exciton and charge transfer excitons (LE-CT) 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.

Författare

Qingzhen Bian

Linköpings universitet

Birhan Alkadir Abdulahi

Addis Ababa University

Wollo University

Chalmers, Kemi och kemiteknik

Zewdneh Genene

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Ergang Wang Group

Ergang Wang

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Ergang Wang Group

W. Mammo

Addis Ababa University

O.W. Inganäs

Linköpings universitet

Journal of Physical Chemistry Letters

1948-7185 (eISSN)

Vol. 11 10 3796-3802

Ämneskategorier

Annan fysik

Annan kemi

Den kondenserade materiens fysik

DOI

10.1021/acs.jpclett.0c00915

PubMed

32338006

Mer information

Senast uppdaterat

2020-08-04