Journal: Science Advances

Article Title: Polymer-Sensitized Hybrid Design Strategy for High-Efficiency Blue Hyperfluorescent OLEDs

doi: 10.1126/sciadv.aee0158

Figure Lengend Snippet: ( A ) Synthesis of PDBA-SAF-P8P. ( B ) Ultraviolet-visible (UV-vis) absorption and photoluminescence (PL) spectra of PDBA-SAF-P8P in toluene (10 –5 M). a.u., arbitrary units. ( C ) Time-resolved PL (TRPL) spectra of PDBA-SAF-P8P in neat film at room temperature. ( D ) Schematic illustrations of film formation by solution processing with planar MR-TADF emitter molecules within small molecular host matrix. Atomic force microscopy (AFM) images of solution-processed films (mCP:DBFPO:ν-DABNA), with emitter weight ratios of ( E ) 3 wt % and ( F ) 10 wt %. ( G ) Schematic illustrations of film formation by solution processing, with MR-TADF molecules uniformly dispersed within the host matrix using a polymer sensitizer. AFM images of solution-processed films (mCP:DBFPO:PDBA-SAF-P8P:ν-DABNA), with 33 wt % polymer sensitizer and emitter weight ratios of ( H ) 3 wt % and ( I ) 10 wt %. ( J ) TRPL spectra of solution-processed films (mCP:DBFPO:ν-DABNA) with various concentrations of MR-TADF emitter. ( K ) Refractive index according to wavelength of solution-processed films with various concentrations of polymer sensitizer and emitter.

Article Snippet: UV-vis absorption spectra were obtained using Jasco V-730 UV-vis spectrophotometers.

Techniques: Microscopy, Polymer, Refractive Index

Journal: Science Advances

Article Title: Polymer-Sensitized Hybrid Design Strategy for High-Efficiency Blue Hyperfluorescent OLEDs

doi: 10.1126/sciadv.aee0158

Figure Lengend Snippet: ( A ) Schematic illustration of f -PEDOT:PSS structure. ( B ) Depth profile of x-ray photoelectron spectroscopy (XPS) measurements of atomic concentrations as a function of etch time for ITO/ f -PEDOT:PSS/EML. ( C ) TRPL spectra of ITO/HIL/EML films using various HILs; the number following “ f -PEDOT:PSS” represents the weight ratio of PFSA to PEDOT. ( D ) Energy level diagram of SOLEDs incorporating 1,3-di(9H-carbazol-9-yl)benzene (mCP), 2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan (DBFPO), and PDBA-SAF-P8P in the EML. ( E ) Normalized UV-vis absorption and PL spectra of solution-processed films containing mCP, DBFPO, PDBA-SAF-P8P, and their blends. ( F ) Device structure of SOLEDs using PDBA-SAF-P8P as emitter. ( G ) Current density versus voltage, ( H ) current efficiency (CE) versus voltage, ( I ) normalized electroluminescence (EL) spectra, and ( J ) normalized capacitance versus voltage characteristics of SOLEDs using mCP single host and mCP:DBFPO mixed host with PEDOT:PSS and f -PEDOT:PSS. Transient EL (trEL) ( K ) rising and ( L ) decaying characteristics of mCP:DBFPO mixed-host SOLEDs with PEDOT:PSS and f -PEDOT:PSS.

Article Snippet: UV-vis absorption spectra were obtained using Jasco V-730 UV-vis spectrophotometers.

Techniques: Spectroscopy

Journal: Science Advances

Article Title: Polymer-Sensitized Hybrid Design Strategy for High-Efficiency Blue Hyperfluorescent OLEDs

doi: 10.1126/sciadv.aee0158

Figure Lengend Snippet: ( A ) Normalized UV-vis absorption of ν-DABNA and PL spectra of PDBA-SAF-P8P in toluene. ( B ) Normalized PL spectra of solution-processed films of MR-TADF [mCP:DBFPO (15 wt %):ν-DABNA (2 wt %)], TADF polymer [mCP:DBFPO (15 wt %):PDBA-SAF-P8P (33 wt %)], and HF [mCP:DBFPO (15 wt %):PDBA-SAF-P8P (33 wt %):ν-DABNA (2 wt %)]. TRPL spectra of ( C ) prompt fluorescence (PF) and ( D ) delayed fluorescence (DF) of solution-processed films. ( E ) PF and DF lifetimes and the DF contribution ratios of solution-processed films. Schematic illustrations of energy transfer process in ( F ) host: MR-TADF emitter system and ( G ) polymer-sensitized HF emission system with rate constants derived from the emission decays. In the HF system, dominant exciton dynamics are governed by the polymer sensitizer, while possible RISC processes within MR-TADF are considered negligible under these conditions. ( H ) Rate constants of radiative decay, intersystem crossing (ISC), andRISC of solution-processed MR-TADF, TADF polymer, and HF films.

Article Snippet: UV-vis absorption spectra were obtained using Jasco V-730 UV-vis spectrophotometers.

Techniques: Polymer, Fluorescence, Derivative Assay