Deep-blue emitter with high photoluminescence efficiency(PLQY)is highly desirable in ultra-high definition displays and white solid-state lightings.In this work,two deep-blue phenanthro[9,10]imidazole derivatives,PPIS...Deep-blue emitter with high photoluminescence efficiency(PLQY)is highly desirable in ultra-high definition displays and white solid-state lightings.In this work,two deep-blue phenanthro[9,10]imidazole derivatives,PPIS and PPPIS,with hot exciton property are successfully developed.Compared to PPIS,the embedded phenyl bridge in PPPIS is able to effectively increase the overlap of frontier molecular orbitals.In consequence,PPPIS shows higher oscillator strength and significantly enhanced PLQY.PPPIS also achieves better electroluminescence performance in non-doped device,showing deep-blue emission with Commission International de l’Eclairage(CIE)coordinates of(0.153,0.087)and the maximum external quantum efficiency(EQEmax)of 8.5%with minuscule efficiency roll-off.Meanwhile,when PPPIS serves as the host for phosphor PO-01,high-efficiency orange phosphorescent device is obtained with high EQEmax of 29.8%and negligible efficiency roll-off at 1000 cd/m^(2).Further,efficient single-emissive-layer white device is assembled via utilizing PPPIS as a blue emitter as well as the host for PO-01 simultaneously,providing warm-white emission with CIE coordinates of(0.429,0.433)at 1000 cd/m^(2),the forward-viewing EQEmaxof 27.2%and maximum power efficiency(PEmax)of 80.1 lm/W,respectively.Our studies can establish a viable design strategy for deep-blue emitters in high-performance non-doped blue OLEDs and hybrid WOLEDs.展开更多
White organic light-emitting diodes(WOLEDs)based on nondoped single emitters can promise convenient fabrication technology,absent phase separation,minimal color-aging,and good reproducibility for next-generation displ...White organic light-emitting diodes(WOLEDs)based on nondoped single emitters can promise convenient fabrication technology,absent phase separation,minimal color-aging,and good reproducibility for next-generation displays and lightings.However,pure organic materials that can radiate intense white light are extremely rare,and the external quantum efficiencies(EQEs)of previously reported nondoped WOLEDs do not exceed 5%.Hence,the straightforward preparation of single white lightemitting molecules for high-performance nondoped WOLEDs remains a high challenging task.Herein,we design and synthesize four hot exciton materials—PhAnPy,DPhAnPy,PIAnPy,and PyIAnPy—which consist of anthracene,pyrene,and imidazole functional groups.Based on the rational manipulation of intermolecular interaction and excited state property,PIAnPy and PyIAnPy display dual emission in the neat films originating from the monomer and excimer emission.Exploiting PIAnPy as a single emitter,a nondoped WOLED is fabricated with a record high EQE of 10.14%,a maximum luminance exceeding 50,000 cd m^(−2)and CIE coordinates of(0.35,0.26).Its EQE is as high as 9.80%at a luminescence of 1000 cd m^(−2),showing a very low efficiency roll-off.To the best of our knowledge,this is the best results of nondoped WOLEDs based on the single-component emitters reported to date.展开更多
基金financial support from National Natural Science Foundation of China(No.22075100)the Jilin Provincial Science and Technology Department(No.20220201082GX)+2 种基金the China Postdoctoral Science Foundation(Nos.2022TQ0111,2023M731267)Sichuan Science and Technology Program(No.2023NSFSC0985)Scientific Research Foundation of Chengdu University of Information Technology(No.KYTZ202174)and the Changsha Automobile Innovation Research Institute。
文摘Deep-blue emitter with high photoluminescence efficiency(PLQY)is highly desirable in ultra-high definition displays and white solid-state lightings.In this work,two deep-blue phenanthro[9,10]imidazole derivatives,PPIS and PPPIS,with hot exciton property are successfully developed.Compared to PPIS,the embedded phenyl bridge in PPPIS is able to effectively increase the overlap of frontier molecular orbitals.In consequence,PPPIS shows higher oscillator strength and significantly enhanced PLQY.PPPIS also achieves better electroluminescence performance in non-doped device,showing deep-blue emission with Commission International de l’Eclairage(CIE)coordinates of(0.153,0.087)and the maximum external quantum efficiency(EQEmax)of 8.5%with minuscule efficiency roll-off.Meanwhile,when PPPIS serves as the host for phosphor PO-01,high-efficiency orange phosphorescent device is obtained with high EQEmax of 29.8%and negligible efficiency roll-off at 1000 cd/m^(2).Further,efficient single-emissive-layer white device is assembled via utilizing PPPIS as a blue emitter as well as the host for PO-01 simultaneously,providing warm-white emission with CIE coordinates of(0.429,0.433)at 1000 cd/m^(2),the forward-viewing EQEmaxof 27.2%and maximum power efficiency(PEmax)of 80.1 lm/W,respectively.Our studies can establish a viable design strategy for deep-blue emitters in high-performance non-doped blue OLEDs and hybrid WOLEDs.
基金supported by the National Natural Science Foundation of China(grant no.22075100)the Jilin Provincial Science and Technology Department(grant no.20220201082GX)+1 种基金Changchun Science and Technology Bureau(grant no.23JQ05)the China Postdoctoral Science Foundation(grant nos.2022TQ0111 and 2023M731267).
文摘White organic light-emitting diodes(WOLEDs)based on nondoped single emitters can promise convenient fabrication technology,absent phase separation,minimal color-aging,and good reproducibility for next-generation displays and lightings.However,pure organic materials that can radiate intense white light are extremely rare,and the external quantum efficiencies(EQEs)of previously reported nondoped WOLEDs do not exceed 5%.Hence,the straightforward preparation of single white lightemitting molecules for high-performance nondoped WOLEDs remains a high challenging task.Herein,we design and synthesize four hot exciton materials—PhAnPy,DPhAnPy,PIAnPy,and PyIAnPy—which consist of anthracene,pyrene,and imidazole functional groups.Based on the rational manipulation of intermolecular interaction and excited state property,PIAnPy and PyIAnPy display dual emission in the neat films originating from the monomer and excimer emission.Exploiting PIAnPy as a single emitter,a nondoped WOLED is fabricated with a record high EQE of 10.14%,a maximum luminance exceeding 50,000 cd m^(−2)and CIE coordinates of(0.35,0.26).Its EQE is as high as 9.80%at a luminescence of 1000 cd m^(−2),showing a very low efficiency roll-off.To the best of our knowledge,this is the best results of nondoped WOLEDs based on the single-component emitters reported to date.
