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Effective host materials are required to improve the performance of phosphorescent organic light-emitting diodes (PhOLEDs). Herein, a series of triazine-dibenzofuran-based n-type host materials, DBT1–DBT4, was prepared by varying the substitution position of dibenzofuran. The photophysical, thermal, and electrochemical properties as well as the device performance of these materials were investigated to establish structure–property relationships. The results demonstrated that the substitution position of dibenzofuran significantly affects the chemical structure, resulting in differences in electrochemical and photophysical properties. All the developed materials were utilized in green top-emitting PhOLEDs as an n-type host material mixed with a p-type host (BPCz), and their electroluminescence (EL) properties were assessed by systematically analysing 18 devices. Among them, the green PhOLEDs using a mixed host of DBT4/BPCz (DBP4-III) displayed the best EL performance with a high current efficiency up to 131.98 cd A−1, an external quantum efficiency up to 30.90%, and a power efficiency up to 105.44 lm W−1 with a device lifetime (T95) of 180 h at 10 000 nits. These findings are expected to aid in the development of improved n-type host materials for highly efficient top-emitting PhOLEDs with long operational lifetimes.

Hybrid organic–inorganic metal perovskites have emerged as highly promising materials for solar energy conversion. However, key questions regarding the working principles of perovskite solar cells remain to be answered in order to improve the design of such devices. In the present study, we have investigated the influence of excess excitation energy on the initial photo-products generated from FTO/meso-TiO2/CH3NH3PbI3 samples. We find that upon resonant excitation at the band edge, part of the formation of free charges passes via an excitonic state that dissociates on the sub-picosecond time scale. An exciton binding energy of

Iodide redox (3I−/I3−), polysulfide redox (S2−/Sx2−), organic redox [TMTU/TMFDS2+: tetramethylthiourea/tetramethylformaminium-bis(trifluoromethanesulfonyl)imide], ferrocene redox (Fc/Fc+), nickel redox [Ni(II)/Ni(III)], and cobalt redox [Co(II)/Co(III)] hole conducting electrolytes were systematically investigated to determine their suitability for use in Sb2S3-sensitized photoelectrochemical solar cells. A long-term stability test and UV-visible spectral analyses revealed that Sb2S3-sensitized photoelectrochemical solar cells worked stably with Co(II)(o-phen)3(TFSI)2/Co(III)(o-phen)3(TFSI)3 [TFSI: bis(trifluoromethanesulfonyl)imide] as the redox mediator.

Performance of Sb(2)S(3)-sensitized heterojunction solar cells is enhanced by embedding Au nanoparticles in the poly-3-hexylthiophene (P3HT) hole-conducting polymer layer. The improved charge transfer/transport at the Sb(2)S(3)/P3HT/Au interface by extended interface area of the P3HT/Au counter electrode and the re-absorption of the backscattering light from the embedded Au nanoparticles enhanced the device performance: J(sc) 11.0 to 12.8 mA cm(-2), V(oc) 606 to 626 mV, fill factor (FF) 60.5 to 61.2%, and power conversion efficiency (η) 4.0 to 4.9%. Simultaneous enhancement of V(oc), J(sc), and FF in Au nanoparticle-embedded systems is mainly attributed to the improved charge collection efficiency and light harvesting efficiency of Sb(2)S(3) due to the improved charge transfer/transport in the Sb(2)S(3)/P3HT/Au interface.

Nanorods of Sb2Se3 have been produced from a newly designed single-source precursor under assistance of ethylene glycol used as solvent without any surfactants or additives. The precursor, [(SbL2Cl2)Cl]2·(CH3)2CO, 1 (L represents N,N-dimethyl selenourea)], has been easily synthesized and characterized by single crystal X-ray diffraction and IR spectroscopy. The extensive network of NH–Cl bonds present in the crystal packing of the complex promoted the formation of Sb2Se3, leaving HCl in the reaction medium. The Sb2Se3 nanocompounds have been characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The mechanism of formation of Sb2Se3 has been proposed and rationalized on the basis of TEM and field emission scanning electron microscopy (FE-SEM) observations of the intermediates throughout the solvent-assisted growth and mass spectral analysis of the reaction mixture during the process.