High-Efficiency Organic Solar Cells (OPVs)
Polymeric donor material
LUMO=?3.6 eV
HOMO=?5.5 eV
OPV Device Performance:
PBDB-T-2F: ITIC-F (1:1 w/w)
Voc= 0.84V
Jsc= 22.2 mA/cm2
FF= 0.725
PCE=13.5%
PBDB-T-2F (or PM6) is a wide bandgap polymer donor (n-type semiconductor) containing fluorinated thienyl benzodithiophene (BDT-2F) used in high performance polymer solar cells (PSCs). PBDB-T-2F possesses high crystallinity and strong π-π stacking alignment, which are favourable to charge carrier transport and hence suppress recombination in devices. PBDBT-2F based PSCs were reported to have thickness and area insensitive performance and is a promising candidate for large-scale roll-to-roll manufacturing of high-efficiency polymer solar cells.
For example, recently, new study have shown PBDB-T-2F:IT-4F(Sigma Aldrich Cat. No. 901423) based PSCs yielded an impressive PCE of 13.5% due to the synergistic effect of fluorination on both donor and acceptor, which is among the highest values recorded in the literatures for PSCs to date [1]. The PBDB-T-2F:IT-4F baed PSCs also showed good storage, thermal and illumination stabilities with respect to the efficiency. High efficiency of >11% was maintained for a wide range of film area and thickness. When paired with selenopheno[3,2-b]thiophene-based narrow-bandgap non-fullerene acceptor, an impressive efficiency of 13.3 % was obtained with thickness-insensitive feature.
It has also been previously reported, PBDB-T-2F when paired with narrow band-gap small molecule acceptor 2,2′-((2Z,2′Z)-((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (IDIC), the as-cast film (without extra treatments) showed an outstanding power conversion efficiency (PCE) of 11.9%, a record value for as-cast polymer solar cells. Moreover, the performance of PBDB-T-2F:IDIC based devices is insensitive to the active layer thickness (?95-255 nm) and device area (0.20-0.81 cm2), and thus is a promising candidate for future roll-to-roll mass manufacturing and practical application of highly efficient PSCs.
It has also been reported, PBDB-T-2F possesses a strong absorption in the short wavelength region of 300-685 nm with a large bandgap of 1.80 eV, which is complementary to that of ITIC (1.55 eV) and facilitates achieving high short-circuit current (Jsc) in PSCs. Moreover, PBDB-T-2F shows a deep HOMO level of ?5.50 eV, a strong crystallinity and a dominant face on packing, which helps to achieve a high open-circuit voltage (Voc) and fill factor (FF) in PSCs.
