ABSTRACT
Correction for 'Polymeric hole-transport materials with side-chain redox-active groups for perovskite solar cells with good reproducibility' by Rosinda Fuentes Pineda et al., Phys. Chem. Chem. Phys., 2018, 20, 25738-25745.
ABSTRACT
Two monomers, M:OO and M:ON, and their corresponding polymers, P:OO and P:ON, were prepared from styrene derivatives N,N-diphenyl-4-vinyl-aniline with different substituents (-OCH3 and -N(CH3)2) in the N-phenyl para positions. The polymers were synthesised and fully characterised to study their function as hole transport materials (HTMs) in perovskite solar cells (PSCs). The thermal, optical and electrochemical properties and performance of these monomers and polymers as HTMs in PSCs were compared in terms of their structure. The polymers form more stable amorphous glassy states and showed higher thermal stability than the monomers. The different substituent in the para position influenced the highest occupied molecular orbital (HOMO) level, altering the oxidation potential. Both monomers and polymers were employed as HTMs in perovskite solar cells with a device configuration FTO/bl-TiO2/mp-TiO2/CH3NH3PbI3/HTM/Au resulting in power conversion efficiencies of 7.48% for M:OO, 5.14% for P:OO, 5.28% for P:ON and 3.52% for M:ON. Although showing comparatively low efficiencies, the polymers showed much superior reproducibility in comparison with Spiro-OMeTAD or the monomers, suggesting further optimisation of polymeric HTMs with redox side groups is warranted.
ABSTRACT
The complexes [Cu(I)(POP)(dmbpy)][BF4] (1) and [Cu(I)(POP)(tmbpy)][BF4] (2) (dmbpy = 4,4'-dimethyl-2,2'-bipyridyl; tmbpy = 4,4',6,6'-tetramethyl-2,2'-bipyridyl; POP = bis[2-(diphenylphosphino)-phenyl]ether) have been studied in a wide temperature range by steady-state and time-resolved emission spectroscopy in fluid solution, frozen solution, and as solid powders. Emission quantum yields of up to 74% were observed for 2 in a rigid matrix (powder), substantially higher than for 1 of around 9% under the same conditions. Importantly, it was found that the emission of 2 at ambient temperature represents a thermally activated delayed fluorescence (TADF) which renders the compound to be a good candidate for singlet harvesting in OLEDs. The role of steric constraints within the complexes, in particular their influences on the emission quantum yields, were investigated by hybrid-DFT calculations for the excited triplet state of 1 and 2 while manipulating the torsion angle between the bipyridyl and POP ligands. Both complexes showed similar flexibility within a ±10° range of the torsion angle; however, 2 appeared limited to this range, whereas 1 could be further twisted with little energy demand. It is concluded that a restricted flexibility leads to a reduction of nonradiative deactivation and thus an increase of emission quantum yield.
ABSTRACT
The first molecular capsule based on an [Ir(ppy)(2)](+) unit (ppy = 2-phenylatopyridine) has been prepared. Following the development of a method to resolve rac-[(Ir(ppy)(2)Cl)(2)] into its enantiopure forms, homochiral Ir(6)L(4) octahedra where obtained with the tritopic 1,3,5-tricyanobenzene. Solution studies and X-ray diffraction show that these capsules encapsulate four of the six associated counteranions and that these can be exchanged for other anionic guests. Initial photophysical studies have shown that an ensemble of weakly coordinating ligands can lead to luminescence not present in comparable mononuclear systems.
Subject(s)
Iridium/chemistry , Luminescence , Organometallic Compounds/chemical synthesis , Pyridines/chemistry , Crystallography, X-Ray , Models, Molecular , Molecular Conformation , Organometallic Compounds/chemistry , StereoisomerismABSTRACT
Mass spectrometry and drift tube ion mobility mass spectrometry have been used to analyse several isobaric, multicomponent cages yielding information on three dimensional structure, interactions and dynamics of assembly in the gas phase.
