β‐Functionalized Push–Pull opp‐Dibenzoporphyrins as Sensitizers for Dye‐Sensitized Solar Cells

Abstract

A novel class of β-functionalized push-pull zinc opp-dibenzoporphyrins were designed, synthesized, and utilized as sensitizers for dye-sensitized solar cells. Spectral, electrochemical, and computational studies were systematically performed to evaluate their spectral coverage, redox behavior, and electronic structures. These porphyrins displayed much broader spectral coverage and more facile oxidation upon extension of the π conjugation. Free-energy calculations and femtosecond transient absorption studies (charge injection rate in the range of 10 s ) suggested efficient charge injection from the excited singlet state of the porphyrin to the conduction band of TiO . The power conversion efficiency (η) of YH3 bearing acrylic acid linkers (η=5.9 %) was close to that of the best ruthenium dye N719 (η=7.4 %) under similar conditions. The superior photovoltaic performance of YH3 was attributed to its higher light-harvesting ability and more favorable electron injection and collection, as supported by electrochemical impedance spectral studies. This work demonstrates the exceptional potential of benzoporphyrins as sensitizers for dye-sensitized solar cells.

Synthesis, Spectral, Electrochemical and Photovoltaic Studies of A3B Porphyrinic Dyes having Peripheral Donors

“…[20,25,28] The highest PCE value of KP-TriPTZ-Zn supports the fact that phenothiazine attached to porphyrin is the best light harvesting and electron donor among the studied groups which is also consistent with reported literature. [20,25,[49][50][51][52][53][54] Electrochemical impedance spectroscopy studies of A 3 B and trans-A 2 BC Zn(II) porphyrin dye modified solar cells were performed to understand the kinetics of charge transfer. [55,56] The Nyquist plot of KP-TriPTZ-Zn and other dyes constructed DSSCs are presented in Figure 6 and Figures S30-S31 in SI, respectively.…”

“…[20] The PCE values of trans-A 2 BC Zn(II) porphyrin dyes follows the trend: RA-199-Zn (η = 2.4 %) < RA-200-Zn (η = 4.2 %) < RA-195-Zn (η = 4.3 %). [20,25,[49][50][51][52][53][54] Electrochemical impedance spectroscopy studies of A 3 B and trans-A 2 BC Zn(II) porphyrin dye modified solar cells were performed to understand the kinetics of charge transfer. However, while increasing the number of donor groups (KP-TriPYR-Zn, KP-TriCBZ-Zn and KP-TriPTZ-Zn), the efficiency increases drastically due to better electron donating ability of peripheral rich groups.…”

Phenanthroline‐Fused Pyrazinacenes: One‐Pot Synthesis, Tautomerization and a RuII(2,2′‐bpy)2 Derivative

“…Figure b shows the calculated structures of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) for compound 6 . These reveal that the HOMO is accommodated largely on the pyrazinacene portion of the molecule while the LUMO lies on the Ru(bpy) 2 moiety, suggesting their ability to promote directional electron transfer in DSSCs by means of push‐pull effect …”

Improved photovoltaic performance of phosphonic acid‐based sensitized solar cells via an electron‐withdrawing moiety: A density of functional theory study

“…Since its launch by Grätzel, [ 8 ] the first used sensitizers were based on metal complexes such as ruthenium (N3 [ 10 ] ) and zinc. [ 11 ] Owing to their complicated synthesis route, cost, and the deterioration to the environment, researchers created metal‐complex dyes through the metal‐free organic sensitizers. The first metal‐free organic dyes have a “pull‐push” donor‐π‐bridge‐acceptor (D‐π‐A) structure, where the donor moiety and the anchoring group are connected by a π‐bridge.…”