Efficient OLEDs Fabricated by Solution Process Based on Carbazole and Thienopyrrolediones Derivatives

Abstract

Four low molecular weight compounds—three of them new, two of them with carbazole (Cz) as functional group and the other two with thienopyrroledione (TPD) group—were used as emitting materials in organic light emitting diodes (OLEDs). Devices were fabricated with the configuration ITO/PEDOT:PSS/emitting material/LiF/Al. The hole injector layer (HIL) and the emitting sheet were deposited by spin coating; LiF and Al were thermally evaporated. OLEDs based on carbazole derivatives show luminances up to 4130 cd/m2, large current efficiencies about 20 cd/A and, cautiously, a very impressive External Quantum Efficiency (EQE) up to 9.5%, with electroluminescence peaks located around 490 nm (greenish blue region). Whereas, devices manufactured with TPD derivatives, present luminance up to 1729 cd/m2, current efficiencies about 4.5 cd/A and EQE of 1.5%. These results are very competitive regarding previous reported materials/devices.

Fabrication of photoluminescent nanoparticles from carbazole-derived chalcones: a study of optical properties, cell biomarking, and metabolism

“…26 It is possible to take advantage of the optical properties of carbazole by including it in the chalcone structure, resulting in band gap values of ∼3.25 eV and an increasing in the ICT. 27,28 The emission of the molecule in solution will depend on the solvent in which it is dissolved due to the change in electron density; where the fluorescence quantum yield can decrease with the increasing of the solvent polarity from 53 to 8%. 29–31…”

“…25 eV and an increasing in the ICT. 27,28 The emission of the molecule in solution will depend on the solvent in which it is dissolved due to the change in electron density; where the fluorescence quantum yield can decrease with the increasing of the solvent polarity from 53 to 8%. [29][30][31] The synthesis of molecules derived from carbazole under D-D-A structure has been reported, these compounds have emission in the infrared region in the solid state since carbazole derivatives are good fluorophores they can be used in the development of potential molecules for cell imaging and photodynamic therapy (PDT).…”

3PTZ and 3PXZ small molecular hole-transporting materials in polymer light-emitting diodes

“…7,9,29,30 Although the spin-coated layers were known to exhibit lower quality than thermally evaporated layers, some studies of spin-coated layers show a comparable quality to thermally evaporated ones. 8,10,11,[31][32][33] In this study, we newly apply novel 3PTZ and 3PXZ small molecular materials as HTLs in PLEDs using spin-coating methods. These attempts using spin coating are for the first time tried in PLED research.…”

“…7,9,29,30 Although the spin-coated layers were known to exhibit lower quality than thermally evaporated layers, some studies of spin-coated layers show a comparable quality to thermally evaporated ones. 8,10,11,31–33…”

Nontoxic pyrite iron sulfide nanocrystals as second electron acceptor in PTB7:PC71BM-based organic photovoltaic cells

“…The performance of the OPVs depends on the misalignment of the energy levels of each component, as well as on the organic compounds and the architecture used, on the type of solvents, the deposition technique of the active layer, the annealing conditions and the thickness and morphology of the devices [32,35]. Spin-coating is one of the most widely used techniques for active layer deposition that provides a small active area film with a low root-mean-squared roughness of about 1–3 nm [36].…”