D–π–A Structured Zn^II‐Porphyrin Dyes with Thiophene Moiety for Highly Efficient Dye‐Sensitized Solar Cells

Abstract

Herein, we design and synthesize a new D–π–A zinc porphyrin, enveloped with a long alkyl thiophene unit (Th‐ZnP‐CNCOOH, TP), for dye‐sensitized solar cells. The long alkyl‐substituted thiophene unit is incorporated into the porphyrin dye to red‐shift its absorption wavelength. The effects of the alkyl thiophene moiety at the meso‐position of the zinc porphyrin on the optical, electrochemical, and photovoltaic properties of the material are investigated. Dye‐sensitized solar cells (DSSCs) prepared using the new dye, co‐adsorbed with a simply structured organic co‐adsorbent (HC‐A4), are fabricated. The obtained TP/HC‐A4‐sensitized DSSCs exhibit a remarkable enhancement in both short‐circuit current (JSC) and open‐circuit voltage (VOC), relative to the corresponding single‐dye DSSCs, which can be attributed to a combination of the light‐harvesting effect from their complementary absorption behavior and the slow charge‐recombination process. The device based on TP/HC‐A4 co‐sensitization yields: JSC=14.4 mA cm−2, VOC=0.62 V, a fill factor FF=0.75 and an efficiency η=6.7 %. This performance is superior to those of devices containing either TP (η=2.4 %) or HC‐A4 (η=2.8 %), fabricated under the same conditions. The present study indicates that the prevention of dye aggregation, as well as complementary absorption spectra of the porphyrin dyes using co‐sensitizers, are key to improving the device performance.

Visible-light-driven hydrogen production from water in a noble-metal-free system catalyzed by zinc porphyrin sensitized MoS 2 /ZnO

“…As the light harvesting centre, the dye must possess some general requirements such as a suitable redox potential, a broad light response, long-term photostability and if possible, it should be inexpensive. Among various dyes, noble-metal-free zinc porphyrin complexes are chromophores well-known for their strong absorption in the 400-450 nm region (Soret band) and two/four less intense absorption bands in the 500-700 nm region (Q-bands), as well as for their excellent photophysics and electrochemistry properties [24,25]. Moreover, zinc porphyrin dyes have suitable redox potentials for electron-injection and dye regeneration, which rendering them attractive as photosensitizers for DSSCs [26][27][28][29][30].…”

Efficient co-sensitization of dye-sensitized solar cells by novel porphyrin/triazine dye and tertiary aryl-amine organic dye

“…7, red line) was found to exhibit panchromatic features showing an enhanced light harvesting efficiency in the 350-650 nm region. The absorption band that corresponds to the ZnP-triazine-(gly) 2 Soret band is slightly broader, suggesting that upon co-sensitization, compound D causes a change in the orientation of the porphyrin molecules adsorbed on the TiO 2 surface that results in a decrease of their aggregation [41]. Furthermore, it should be noted that energy transfer efficiency from D to ZnP-triazine-(gly) 2 expected to be low.…”

Axial coordination reactions with nitrogenous bases and determination of equilibrium constants for zinc tetraarylporphyrins containing four β,β′-fused butano and benzo groups in nonaqueous media

“…Synthetic zinc porphyrins are one of the most studied metalloporphyrin derivatives, in part because they have wide potential applications in the fields of solar cells [1][2][3][4][5], nanomaterials [6,7] and supramolecular chemistry [8][9][10][11][12][13]. Among the examined compounds are the zinc tetrabenzoporphyrins which possess an extended conjugated system [14][15][16][17][18][19] and have attracted particular attention due to their unique UV-vis spectral and electrochemical properties [20][21][22][23] as compared to the non-b,b′-pyrrole fused derivatives.…”