Solution-processable phenothiazine and phenoxazine substituted fluorene cored nanotextured hole transporting materials for achieving high-efficiency OLEDs

Abstract

In this work, a novel series of phenothiazine and phenoxazine substituted fluorene core-based solution-processable nanotextured HTMs was reported. Of these, the phenoxazine material showed a superior performance in phosphorescent yellow and TADF green OLEDs.

Benzothiadiazole-based fluorophores as efficient non-doped emitters for solution-processed organic light-emitting diodes

“…While 7-(4-(carbazol-9-yl)phenyl)-9,9-bis(8-(3,6-di- tert -butylcarbazol-9-yl)octyl)fluorene or 7-(4-(diphenylamino)phenyl)-9,9-bis(8-(3,6-di- tert -butylcarbazol-9-yl)octyl)fluorene will provide collective properties of good organic solvent solubility and hole-transporting ability through their pendant 3,6-di- tert -butyl-8-octylcarbazoles and end-capping 4-(carbazol-9-yl)phenyl/4-(diphenylamino)phenyl units. 33–39 Indeed, both CPBFPhC and CPBFTPA emit an intense yellow-green color with an HLCT property, solution-processability, and high solid-state PL efficiency, and hence, their simple solution-processed non-doped OLEDs attain outstanding EL performances (EQE max = 4.96–5.91%; CE max = 10.27–13.19 cd A −1 ) and a high EUE of 32–37%, which is nearly comparable to the EL performance of its paternal HLCT molecule CzP-BZP-based thermally evaporated multiple layered OLED (EQE max = 6.95%, EUE = 48%). 19…”

“…In this design, 4-(carbazol-9-yl)phenyl)benzothiadiazole (CBz) as a donor-acceptor (D-A) HLCT fragment is directly attached to either 7-(4-(carbazol-9yl)phenyl)-9,9-bis( 8 and end-capping 4-(carbazol-9-yl)phenyl/4-(diphenylamino)phenyl units. [33][34][35][36][37][38][39] Indeed, both CPBFPhC and CPBFTPA emit an intense yellow-green color with an HLCT property, solution-processability, and high solid-state PL efficiency, and hence, their simple solution-processed non-doped OLEDs attain outstanding EL performances (EQE max = 4.96-5.91%; CE max = 10.27-13.19 cd A À1 ) and a high EUE of 32-37%, which is nearly comparable to the EL performance of its paternal HLCT molecule CzP-BZP-based thermally evaporated multiple layered OLED (EQE max = 6.95%, EUE = 48%). 19…”

Carbazole and dibenzo[b,d]furan-based hole transport materials with high thermal stability

“…HTMs are closely related to the EL performance of the device as they reduce the energy barriers for hole injection, thus confining the recombination region of excitons. 15,16 The thermal properties of HTMs are of crucial significance to developing advanced OLEDs, as almost all the device fabrication technologies previously reported (such as thermal evaporation 17,18 and solution processing 19,20 ) require the use of materials with high thermal stability 21 to satisfy the standards of annealing treatment or thermal evaporation. More importantly, by virtue of thermal stability, the Joule heat resistance of the device will be enhanced to boost its efficiency and lifetime.…”

Structure–property investigations in urea tethered iodinated triphenylamines

“…spin coating, ink-jet or gravure printing or slot-die coating) as these can be deposited cheaply and with high throughput employing conventional printing equipment. 22–24…”

“…spin coating, ink-jet or gravure printing or slot-die coating) as these can be deposited cheaply and with high throughput employing conventional printing equipment. [22][23][24] Single crystal X-ray diffraction (SC-XRD) techniques can be employed to extract structural information for correlation with functional features. Osman and coworkers recently crystallized TPA-based Spiro-OMeTAD via the anti-solvent method and employed it as a hole transfer layer in perovskite solar cells.…”