Formation of Highly Efficient, Long‐Lived Charge Separated States in Star‐Shaped Ferrocene‐Diketopyrrolopyrrole‐Triphenylamine Donor–Acceptor–Donor Conjugates

Abstract

The significance of multiple number of donor-acceptor entities on ac entral electron donor in as tar-shaped molecular system in improvingl ight energy harvesting ability is reported.F or this, donor-acceptor-donor type conjugates comprised up to three entities ferrocenyl (Fc)-diketopyrrolopyrrole (DPP) onto ac entral triphenylamine (TPA), (4-6)b yt he Pd-catalyzedS onogashira cross-couplingr eactions have been newly synthesized and characterized. Donor-acceptor conjugates possessing diketopyrrolopyrrole (1 to 3 entities) onto the central triphenylamine, (1-3)s erved as reference dyads while monomericD PP and Fc-DPP served as controlc ompounds. Both DPP and Fc-DPP carrying conjugates exhibited red-shifted absorption compared to their respectivec ontrol compounds revealinge xistenceo fg round state interactions.F urthermore,D PP fluorescencei n4-6 was found to be quantitatively quenched while for 1-3,t his property varied between 73-65 %s uggesting occurrence moderate amountso fe xcited state events. The electrochemical investigationse xhibited an additional low potentialo xidation in the case of Fc-DPP-TPAb ased derivatives(4-6) [a] C.

Annealing Controls Ultrafast Dynamics of Carrier Production in Organic Photovoltaics Incorporating a Nonfullerene Acceptor

“…In the region from 640 to 800 nm, both films feature a broad excited-state absorption (ESA) (Figure b,e). As part of the ESA, the SVA film has an additional sharp peak feature at 780 nm, which has been previously observed in the transient absorption spectra of DPP . Consistent with the differences in spectral features, the dynamics across the visible region, shown through representative kinetic traces, vary for the SVA film (Figure c) but remain constant for the TA film (Figure f).…”

“…As part of the ESA, the SVA film has an additional sharp peak feature at 780 nm, which has been previously observed in the transient absorption spectra of DPP. 32 Consistent with the differences in spectral features, the dynamics across the visible region, shown through representative kinetic traces, vary for the SVA film (Figure 3c) but remain constant for the TA film (Figure 3f). This signals the contribution of multiple excited-state species to the features in the SVA film, but only one excited state species contributes to the features in the TA film.…”

“…The additional excited-state species contributing to the visible transient absorption features in the SVA film is DPP, which has a GSB in the same region. 32 In contrast to the visible region where there are overlapping contributions from PDI and DPP, the NIR region has dominant features from PDI. 33 In particular, the ESA around 1300 nm (Figure 4a,c) has been previously attributed to a PDI excimer transition to a higher energy state with more charge transfer character.…”

Branched Electron-Donor Core Effect in D-π-A Star-Shaped Small Molecules on Their Properties and Performance in Single-Component and Bulk-Heterojunction Organic Solar Cells †

“…Investigations of D-A small molecules demonstrate that even minor adjustments in the molecule structure can lead to significant changes in material characteristics, which may be used for fine tuning the material properties [14][15][16]. Donor-acceptor molecules of star-shaped architecture have several advantages over linear ones, for example, enhanced solubility, lower anisotropy of electrical and optical properties, higher value of molar extinction coefficients and increased number of pathways for light conversion [17][18][19][20][21][22][23][24][25]. Triphenylamine (TPA) is a branching core widely used to design hole-transporting star-shaped and branched molecules for various optoelectronic applications [22,23,[26][27][28][29][30][31][32].…”

A Convenient Synthesis of Diketopyrrolopyrrole Dyes

“…An attractive approach to new DPPs involves the modification of adequately functionalized DPP derivatives. The Suzuki–Miyaura, Stille, Sonogashira, and Heck coupling reactions using bromophenyl, bromothienyl, and bromofuryl DPP derivatives have been extensively used for the preparation of small DPP molecules and polymeric DPP-based materials [ 16 , 17 , 26 , 48 , 49 , 50 , 51 , 52 , 53 ]. Although these are very versatile and efficient reactions, again, the required brominated derivatives are expensive or not easily accessible.…”