Hole Injection/Transport Materials Derived from Heck and Sol−Gel Chemistry for Application in Solution-Processed Organic Electronic Devices

Abstract

An organosilicate polymer, based on N,N'-diphenyl-N,N'-bis(4-((E)-2-(triethoxysilyl)vinyl)phenyl)biphenyl-4,4'-diamine (TEVS-TPD) with extended conjugation between the Si atom and the aromatic amine, was prepared under mild conditions via sequential Heck and sol-gel chemistry and used as an alternative to poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), the most widely used planarizing hole injection/transport layer in solution-processed organic electronic devices. Spin-coating TEVS-TPD polymer solutions yield defect-free, uniform, thin films with excellent adhesion to the ITO electrode. Upon thermal cross-linking at 180 °C, the cross-linked polymer exhibits excellent solvent resistance and electrochemical stability. Solution-processed organic light emitting diode (OLED) devices using iridium-based triplet emitting layers and cross-linked TEVS-TPD films as a hole injection/transport layer show significantly improved performance including lower leakage current, lower turn-on voltage, higher luminance, and stability at high current density, as compared to the control device prepared with PEDOT:PSS.

Recent Advances in Nonfullerene Acceptors for Organic Solar Cells

“…Due to the advantages such as low cost, easy modification, friendly environment, light weight, and mechanical flexibility, solution‐processable organic semiconductors gain the increasing attention. Both conjugated small molecules and polymers, which possess an enormously extended conjugated system, can be employed into the organic optoelectronic devices, such as organic light emitting diodes, organic thin‐film transistors, and organic solar cells (OSCs),. In fact, the first conceptual OSCs were reported by Kallmann and Pope in 1959 that consisted of a pristine single crystal anthracene material between two electrodes .…”

Solution-Processed Blue/Deep Blue and White Phosphorescent Organic Light-Emitting Diodes (PhOLEDs) Hosted by a Polysiloxane Derivative with Pendant mCP (1,3-bis(9-carbazolyl)benzene)

“…To improve thermal, electrochemical, and morphological stability and to enhance the film-forming ability of organic 5 semiconductors, siloxanes have been combined with organic molecular structures; this has a minimal effect on the electronic properties of the materials. [42][43][44][45][46][47] Previously a polytetraphenylsilane derivative with a pendant carbazole unit 48 and a bipolar poly(phenylcarbazole-alt-triphenylphosphine oxide) siloxane 49 have served as hosts for blue and deep blue phosphors. We now report the synthesis of the new mCP-modified polysiloxane (PmCPSi) which incorporates mCP moieties as pendant groups linked via a phenoxy spacer unit, which is designed to remove the detrimental steric crowding between the siloxane backbone and the mCP units observed in a previous oligomer.…”

Efficient preparation of ultralarge graphene oxide using a PEDOT:PSS/GO composite layer as hole transport layer in polymer-based optoelectronic devices

“…18,19 In addition, the radiative exciton quenching generally happens at the interface between the PEDOT:PSS and the emission layer because of the low conductivity of PEDOT:PSS, leading to a decrease in the efficiency of PLEDs. 20 These problems make it necessary to modify PEDOT:PSS by depositing a few nano-sized interlayers between ITO and the active layer [21][22][23][24][25][26] or with a p-type metal oxide such as MoO 3 , 27,28 or NiO 29,30 to solve the problems associated with PEDOT:PSS regarding device stability and efficiency.…”