Kushwaha Aparna, Srivastava Devyani, Prakash Om, Kociok-Köhn Gabriele, Gosavi Suresh W, Chauhan Ratna, Muddassir Mohd, Kumar Abhinav
Department of Chemistry, Faculty of Science, University of Lucknow, Lucknow 226 007, India.
Materials and Chemical Characterisation Facility (MC2), University of Bath, Claverton Down, Bath, BA2 7AY, UK.
Dalton Trans. 2024 Apr 16;53(15):6818-6829. doi: 10.1039/d4dt00151f.
Three new d- and d-configuration based 1,1'-bis-(diphenylphosphino)ferrocene (dppf) appended thiosquarates complexes with general composition [M(mtsq)dppf] (M = Ni (NiL2); Zn (ZnL2) and Cd (CdL2)) (mtsq = 3-ethoxycyclobutenedione-4-thiolate) have been synthesized and characterized spectroscopically as well as in case of NiL2 by single crystal X-ray diffraction technique. The single crystal X-ray analysis reveals square planar geometry around Ni(II) in NiL2, where Ni(II) coordinates with two sulfur centres of two mtsq ligands in monodentate fashion and two phosphorus of a dppf ligand in chelating mode. The supramolecular architecture of NiL2 is sustained by intermolecular C-H⋯O interactions to form one-dimensional chain. Further, the application of these newly synthesized complexes as sensitizers and co-sensitizers/co-absorbents with ruthenium based N719 sensitizer in dye-sensitized solar cells (DSSCs) have been explored. The DSSC set-up based on NiL2 offers best photovoltaic performance with photovoltaic efficiency () 5.12%, short-circuit current () 11.60 mA cm, open circuit potential () 0.690 V and incident photon to current conversion efficiency (IPCE) 63%. In co-sensitized DSSC set-up, ZnL2 along with state-of-the-art N719 dye displays best photovoltaic performance with 6.65%, 14.47 mA cm, 0.729 V and IPCE 69%, thereby showing an improvement by 15.25% in photovoltaic efficiency in comparison to the photovoltaic efficiency of N719 sensitized DSSC set-up. Variation in co-sensitization behaviour have been ascribed to the differences in the excited state energy level of co-sensitizers. The ZnL2 and CdL2 have a higher energy level position than N719 dye, allowing efficient electron transfer to N719 during light irradiation, while excited state of NiL2 is lower than N719 dye, preventing photoexcited electron transfer to N719, resulting in its lowest overall efficiency among the three co-sensitized DSSC setups.
合成了三种基于新的d-和d-构型的1,1'-双（二苯基膦基）二茂铁（dppf）连接硫代方酸配合物，其通式为[M(mtsq)dppf]（M = Ni (NiL2)；Zn (ZnL2) 和Cd (CdL2)）（mtsq = 3-乙氧基环丁烯二酮-4-硫醇盐），并通过光谱进行了表征，对于NiL2还采用单晶X射线衍射技术进行了表征。单晶X射线分析揭示了NiL2中Ni(II)周围的平面正方形几何结构，其中Ni(II)以单齿方式与两个mtsq配体的两个硫中心以及以螯合模式与一个dppf配体的两个磷配位。NiL2的超分子结构通过分子间C-H⋯O相互作用得以维持，形成一维链。此外，还探索了这些新合成的配合物作为敏化剂以及与基于钌的N719敏化剂一起作为共敏化剂/共吸收剂在染料敏化太阳能电池（DSSC）中的应用。基于NiL2的DSSC装置具有最佳的光伏性能，光伏效率（）为5.12%，短路电流（）为11.60 mA cm，开路电位（）为0.690 V，入射光子到电流转换效率（IPCE）为63%。在共敏化DSSC装置中，ZnL2与最先进的N719染料一起表现出最佳的光伏性能，为6.65%，为14.47 mA cm，为0.729 V以及IPCE为69%，因此与N719敏化的DSSC装置的光伏效率相比，光伏效率提高了15.25%。共敏化行为的差异归因于共敏化剂激发态能级的不同。ZnL2和CdL2的能级位置高于N719染料，使得在光照期间能够有效地将电子转移到N719，而NiL2的激发态低于N719染料，阻止了光激发电子转移到N719，导致其在三种共敏化DSSC装置中总体效率最低。
