Lead‐Doped Titanium‐Oxo Clusters as Molecular Models of Perovskite‐Type PbTiO₃ and Electron‐Transport Material in Solar Cells

Abstract

In this work we have successfully prepared two lead-doped titanium-oxo clusters with core structures that resemble isolated perovskite PbTiO 3 species. In the obtained highly symmetric Pb 8 Ti 7 -oxo cluster, the central TiO 6 octahedra are orthogonally extended to adjacento ctahedra throughc orner-sharingandt he eight dopant lead ions form ac ubic arrangement, making it the first molecular model of perovskite PbTiO 3 .M oreover,t he clusters readily dissolved in chloroform and showedh ighs olution stability, as confirmed by MALDI-TOF MS measurements. Based on such solution processability,t hey can be easily spin-coatedt of orm homogeneous films, whichw ere employed as electron-transport materials in perovskite solar cells to give an averagep ower conversion efficiency of around 15 %a nd improvedd evice stability. This newly developed bottom-up cluster assembly method provides an efficienta pproach to the construction of atomically precise modelso fp erovskite metal oxidesa s well as potential molecular tools to extendt heir applications.Ap re-designed pattern was etched on an FTO glass substrate with dimensions of 2.0 cm 2.0 cm by using al aser etch instrument (instrument type JW-20W-KS). The FTO glass substrate was cleaned by ultrasonication for 10 min in ab ath of acetone, ultrapure water,

Calixarene-Protected Titanium-Oxo Clusters and Their Photocurrent Responses and Photocatalytic Performances

“…Their unique properties, such as multiple active sites, diverse configurations, and rich coordination modes, make them one of the most attractive choices for use as modified ligands in TOCs. The use of calixarenes in metal coordination compounds has been intensively investigated; − however, Ti-calixarene complexes have received far less attention than those of other metals. − To the best of our knowledge, the first calixarene-protected TOC was published independently by Power and Atwood . Research work on the molecular structure, binding modes, and chemical modifications of these complexes has subsequently been published. − Yuan et al isolated a monomeric bowl-like pyrogallol[4]­arene Ti 12 coordination complex, which is the highest-nuclearity TOC derived from calixarenes .…”

“…The use of calixarenes in metal coordination compounds has been intensively investigated; − however, Ti-calixarene complexes have received far less attention than those of other metals. − To the best of our knowledge, the first calixarene-protected TOC was published independently by Power and Atwood . Research work on the molecular structure, binding modes, and chemical modifications of these complexes has subsequently been published. − Yuan et al isolated a monomeric bowl-like pyrogallol[4]­arene Ti 12 coordination complex, which is the highest-nuclearity TOC derived from calixarenes . More recently, Liu et al reported a family of calixarene-protected TOCs synthesized by a carboxylate-driven assembly strategy and investigated the structural dependence of the hydrogen-evolution ability of these TOCs .…”

An Organic–Inorganic Hybrid Material Based on Benzo[ghi]perylenetri-imide and Cyclic Titanium-Oxo Cluster for Efficient Perovskite and Organic Solar Cells

“…[26][27][28][29][30][31][32][33][34][35][36][37][38] Although organic chromophore appending TOCs have exhibited efficient electron communication and considerable photocurrent in model DSSCs, [39][40][41] there were few reports about the application in high performing photovoltaics. [42,43] One challenge is how to attach organic dyes onto TOCs, in which the trial-anderror one-pot approach is quite inefficient for bulky dye ligands protecting TOCs. [44] A feasible way is the functionalization of as-synthesized clusters, such as ligand exchange at surface labile sites.…”

Ti-Oxo Clusters with Peripheral Alkyl Groups as Cathode Interlayers for Efficient Organic Solar Cells

“…Transition metal oxides, such as ZnO, TiO 2 , and SnO 2 , are commonly used as CILs in OSCs. , In general, metal oxides can be sol–gel-processed or used as nanoparticles, which display low cost, low WF, high conductivity, and good stability. Nonetheless, metal oxides often suffer from the UV doping and surface defects, which can result in the device degradation and contact issues between the layers. − Some of these issues can be addressed by the so-called surface modification strategy, such as inserting an organic interlayer between metal oxides and the photo-active layer or conducting surface transformation on the colloid directly. − Ti-oxo clusters (TOCs) that simultaneously contain metal oxides as the core and organic materials on the periphery of the core can meet the requirement, but they have been rarely applied as interlayers in OSCs. − TOCs have been developed into a big library with hundreds of structures. − In essence, organic ligand-stabilized TOCs can be seen as ultra-small titanium oxide nanoparticles with an organic protecting layer on the surface. They usually display similar band gaps and tunable WF but better film formation compared to normal TiO 2 nanomaterial. , Therefore, TOCs have great potential to be used as efficient CILs in organic photovoltaics.…”