Boosting inverted perovskite solar cell performance by using 9,9-bis(4-diphenylaminophenyl)fluorene functionalized with triphenylamine as a dopant-free hole transporting material
In this study, two newly developed small molecules based on 9,9-bis(4-diphenylaminophenyl)fluorene functionalized with triphenylamine moieties, namely TPA-2,7-FLTPA-TPA and TPA-3,6-FLTPA-TPA, are designed, synthesized and characterized. The electrochemical, optical and thermal properties of both materials are investigated using various techniques. Afterwards, these materials are employed as dopant-free hole transporting materials (HTMs) in planar inverted perovskite solar cell devices with the aim of determining the device performance and studying their stability in comparison with reference N4,N4,N4′′,N4′′-tetra([1,10-biphenyl]-4-yl)-[1,1′:4′,1′′-terphenyl]-4,4′′-diamine (TaTm)-based devic…
Iron(II) Spin Transition Complexes with Dendritic Ligands, Part I
The ligands G1- and G2-oligo (benzyl ether) (PBE) dendrons and their iron(II) complexes [Fe(Gn-PBE)3]A2·xH2O (with n = 1, 2 and A = triflate, tosylate) were prepared. The magnetic properties of the complexes were investigated by a SQUID magnetometer. All complexes exhibit gradual spin transition below room temperature. At very low temperatures the magnetic behaviour reflects zero-field splitting (ZFS) effects. 57Fe-Mossbauer spectroscopy was performed to distinguish between ZFS of high spin species and spin state conversion into the low spin state. Further characterisation was carried out by thermogravimetric analysis (TGA) and FT-IR spectroscopy. Structural features have been determined by…
Pyridine-Incorporated Dihexylquaterthiophene: A Novel Blue Emitter for Organic Light Emitting Diodes (OLEDs)
The synthesis and characterisation of 2,5-bis(5′-hexyl-[2,2′-bithiophen]-5-yl)pyridine (Th4PY) and its use as a blue emitter in organic light emitting diodes (OLEDs) is reported. Th4PY was synthesised in high yield using a straightforward Suzuki coupling route with commercially available starting materials. As Th4PY is both soluble and has low molecular weight, blue OLEDs were fabricated using both spin-coating and vacuum deposition thin film processing techniques to study the effect of processing on device performance. OLED devices using a spin-coated layer consisting of 4′,4′′-tris(N-carbazolyl)triphenylamine (TCTA) and 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) as a …