A Triphenylamine–Naphthalenediimide–Fullerene Triad: Synthesis, Photoinduced Charge Separation and Solution‐Processable Bulk Heterojunction Solar Cells

Abstract

An ew naphthalenediimide (NDI) derivative linked to triphenylamine (TPA) and fullerene (TPA-NDI-C 60 triad; S3)w as designed, synthesized and characterized. Femtosecond laser transienta bsorption spectralm easurements revealed that fast electron transfer from TPAt ot he singlet-excited state of NDI occurredt of orm ac harge-separated state (TPAC + -NDIC À -C60) with ar ate constanto fa pproximately 10 12 s À1,f ollowed by the charge-shift reaction from NDIC À to C 60 to produce the charge-separated state (TPAC + -NDI-C 60 C À ) that decayed by back electron transfer with ar ate constant of 4.4 10 9 s À1 (with ac orresponding lifetime of 230 ps). Organic bulk heterojunction solar cells were fabricatedu sing the triad S3 as an n-type semiconductor along with the conventional donorp olymer poly(3-hexylthiophene). The power conversion efficiency reached 3.03 %b efore annealing and 4.85 %a fter annealing in the optimized devices. To rationalize the performance of these organic photovoltaic devices, atomic force microscopy was used to study the morphology of poly(3-hexylthiophene):S3 blend surfaces, which were found to be well interlaced and free from projections, lumps,ori ndentations.

Ultrafast Photoinduced Electron Transfers in Platinum(II)-Anthraquinone Diimine Polymer/PCBM Films

“…Nonetheless in all cases, the transient species are formed within the laser pulse with no rise time exceeding the IRF (127–141 fs) meaning that the rate for electron transfer, k et ≥ 6.6 × 10 12 s –1 . This conclusion is fully consistent with the experimentally determined k et values reported for other related PCBM-containing molecular models and blends, − although somewhat slower rates have also been reported (with time scales ranging from 360 to 420 fs), , and is also consistent with the conclusion drawn above that in the case of an oxidative quenching ( P x * + PCBM → P x +• + PCBM –• ), the k et values must be very large to overcome the rather short-lived S 1 state of P1 and P2 , which are in the order of 10 ps (i.e., τ­(S 1 ) ≤ 8–21 ps, at 298 K, in solution and as films).…”

Influence of the fluoride anion on photoinduced charge transfer interactions in adenine-functionalized push–pull naphthalenediimide chromophores

“…NDIs have been employed as an acceptor in combination with different donors to establish the charge transport properties. 19 Importantly, core-substituted NDIs can be utilized to recognize fluoride anions leading to modulation of their photophysical and electrochemical properties. 20 A literature search revealed that in supramolecular D–A complex systems, anion binding at the donor macrocycle influences the excited state electron transfer properties.…”

Triphenylamine-Merocyanine-Based D1-A1-π-A2/A3-D2 Chromophore System: Synthesis, Optoelectronic, and Theoretical Studies

“…On the other hand, triphenylamine (TPA) has been recognized as a very promising electron-donor unit due to its charge transport characteristics [44,45,46,47,48,49]. TPA and its derivatives were used in various fields such as electrochromism, organic electronics, two-photon absorption, DSSCs, and organic photovoltaics [50,51,52,53,54,55].…”