Blue phosphorescent OLEDs(Ph-OLEDs)have long faced critical challenges in efficiency,stability and brightness,which are crucial for advanced display.Herein,we introduce two novel Ir(III)emitters featuring a 3,6-di(ter...Blue phosphorescent OLEDs(Ph-OLEDs)have long faced critical challenges in efficiency,stability and brightness,which are crucial for advanced display.Herein,we introduce two novel Ir(III)emitters featuring a 3,6-di(tert-butyl)-9Hcarbazolyl(tBuCz)substituted tridentate carbene pincer ligand,significantly improving efficiency and stability.The tBuCz-m-CF3 and tBuCz-p-CF3 complexes are designed to enhance steric encumbrance and minimize exciton accumulation.These innovations lead to exceptional photoluminescence quantum yields(PLQY)of 98%and an impressive decay rate constant of 7.97×10^(5)s^(−1)in doped thin films.The Ph-OLEDs emit blue light with a peak wavelength of 485 nm and CIE coordinates of(0.175,0.446),exhibiting a peak external quantum efficiencies(EQE)of 31.62%and brightness up to 214,255 cdm^(−2).Notably,they shown minimal efficiency roll-off,retaining an EQE of 27.76%at 10,000 cdm^(−2),and 20.58%at 100,000 cdm^(−2).These consistent performances across various brightness levels represent a significant milestone for blue Ph-OLED technology.The devices also exhibit impressive stability,with an operational lifetime(LT50,the time taken for luminance to decrease by 50%)reaching 1237 h at 1000 cdm^(−2),setting new benchmarks for blue Ph-OLEDs.To enhance the color purity,hyper-OLEDs were developed with a full width at half maximum(FWHM)of 20 nm and the CIEy of 0.233,achieving an EQEm of 29.78%and LT50 of 318 h at 1000 cdm^(−2).We also fabricated the active-matrix(AM)blue Hyper-OLEDs with 400 pixels per inch to demonstrate their application in AM displays.展开更多
Broadband photodetectors(PDs)capable of multi-wavelength detection have garnered significant interest for applications in environmental monitoring,optical communication,spectral analysis,and imaging sensing.Low-bandga...Broadband photodetectors(PDs)capable of multi-wavelength detection have garnered significant interest for applications in environmental monitoring,optical communication,spectral analysis,and imaging sensing.Low-bandgap Pb-Sn hybrid perovskite photodetectors can extend the spectral response from the ultraviolet-visible(UV-vis)range to the near-infrared(NIR)and reduce the toxicity associated with Pb^(2+).The strategic introduction of Sn^(2+)into Cs_(0.15)FA_(0.85)Pb_(x)Sn_(1-x)I_(3)(x=1,0.8,0.6,0.5,0.4,0.2,and 0)not only preserves the cubic crystal structure with conformal multigrain growth but also broadens the film's absorption spectrum from 800 to 1000 nm NIR region.This indicates a well-controlled tunability of the Pb-Sn binary perovskite system.Specifically,the self-powered photodetector with a device structure of ITO/NiO_(x)/PTAA/Cs_(0.15)FA_(0.8)5Pb^(0.5)Sn_(0.5)I_(3)/PCBM/BCP/Ag has shown remarkable optoelectrical properties.It exhibits a high external quantum efficiency(EQE)of up to 80%across the spectrum from 300 to 1000 nm,a responsivity(R)exceeding 0.5 A/W,and high detectivity(D^(*))value of 1.04×10^(12)Jones at 910 nm and 3.38×10^(11)Jones at 1000 nm after weak attenuation.Intriguingly,the dark current of the Cs_(0.15)FA_(0.85)Pb_(0.5)Sn_(0.5)I_(3)device is four orders of magnitude lower than that of devices made with pristine Pb or Sn only,strongly correlating with its significantly increased built-in potential and reduced trap density.Consequently,it demonstrates a3 dB bandwidth of 2.23104 Hz,fast rise and decay times of 61 and 30μs,respectively,and a linear dynamic range(LDR)of 155 dB.Benefiting from its high sensitivity,a 5×5 PD array for NIR imaging and non-invasive pulse detection for photoplethysmography applications has been successfully demonstrated,showcasing the prosperous potential of Pb-Sn hybrid perovskite in the NIR range.展开更多
基金the National Natural Science Foundation of China(grant no.:52027817)Shenzhen Science and Technology Innovation Commission(grant no.:GJHZ20210705143204013)+1 种基金Research Grant Council of Hong Kong(grant no.:CityU 11312722)lShenzhen Science and Technology Innovation Commission(grant no.:JCYJ20200109144614514)China Postdoctoral Science Foundation(grant no:2024M761639).
文摘Blue phosphorescent OLEDs(Ph-OLEDs)have long faced critical challenges in efficiency,stability and brightness,which are crucial for advanced display.Herein,we introduce two novel Ir(III)emitters featuring a 3,6-di(tert-butyl)-9Hcarbazolyl(tBuCz)substituted tridentate carbene pincer ligand,significantly improving efficiency and stability.The tBuCz-m-CF3 and tBuCz-p-CF3 complexes are designed to enhance steric encumbrance and minimize exciton accumulation.These innovations lead to exceptional photoluminescence quantum yields(PLQY)of 98%and an impressive decay rate constant of 7.97×10^(5)s^(−1)in doped thin films.The Ph-OLEDs emit blue light with a peak wavelength of 485 nm and CIE coordinates of(0.175,0.446),exhibiting a peak external quantum efficiencies(EQE)of 31.62%and brightness up to 214,255 cdm^(−2).Notably,they shown minimal efficiency roll-off,retaining an EQE of 27.76%at 10,000 cdm^(−2),and 20.58%at 100,000 cdm^(−2).These consistent performances across various brightness levels represent a significant milestone for blue Ph-OLED technology.The devices also exhibit impressive stability,with an operational lifetime(LT50,the time taken for luminance to decrease by 50%)reaching 1237 h at 1000 cdm^(−2),setting new benchmarks for blue Ph-OLEDs.To enhance the color purity,hyper-OLEDs were developed with a full width at half maximum(FWHM)of 20 nm and the CIEy of 0.233,achieving an EQEm of 29.78%and LT50 of 318 h at 1000 cdm^(−2).We also fabricated the active-matrix(AM)blue Hyper-OLEDs with 400 pixels per inch to demonstrate their application in AM displays.
基金the National Natural Science Foundation of China(grant no.52027817)Shenzhen Science and Technology Innovation Committee(grant nos.GJHZ20210705143204013 and JCYJ20200109144614514).
文摘Broadband photodetectors(PDs)capable of multi-wavelength detection have garnered significant interest for applications in environmental monitoring,optical communication,spectral analysis,and imaging sensing.Low-bandgap Pb-Sn hybrid perovskite photodetectors can extend the spectral response from the ultraviolet-visible(UV-vis)range to the near-infrared(NIR)and reduce the toxicity associated with Pb^(2+).The strategic introduction of Sn^(2+)into Cs_(0.15)FA_(0.85)Pb_(x)Sn_(1-x)I_(3)(x=1,0.8,0.6,0.5,0.4,0.2,and 0)not only preserves the cubic crystal structure with conformal multigrain growth but also broadens the film's absorption spectrum from 800 to 1000 nm NIR region.This indicates a well-controlled tunability of the Pb-Sn binary perovskite system.Specifically,the self-powered photodetector with a device structure of ITO/NiO_(x)/PTAA/Cs_(0.15)FA_(0.8)5Pb^(0.5)Sn_(0.5)I_(3)/PCBM/BCP/Ag has shown remarkable optoelectrical properties.It exhibits a high external quantum efficiency(EQE)of up to 80%across the spectrum from 300 to 1000 nm,a responsivity(R)exceeding 0.5 A/W,and high detectivity(D^(*))value of 1.04×10^(12)Jones at 910 nm and 3.38×10^(11)Jones at 1000 nm after weak attenuation.Intriguingly,the dark current of the Cs_(0.15)FA_(0.85)Pb_(0.5)Sn_(0.5)I_(3)device is four orders of magnitude lower than that of devices made with pristine Pb or Sn only,strongly correlating with its significantly increased built-in potential and reduced trap density.Consequently,it demonstrates a3 dB bandwidth of 2.23104 Hz,fast rise and decay times of 61 and 30μs,respectively,and a linear dynamic range(LDR)of 155 dB.Benefiting from its high sensitivity,a 5×5 PD array for NIR imaging and non-invasive pulse detection for photoplethysmography applications has been successfully demonstrated,showcasing the prosperous potential of Pb-Sn hybrid perovskite in the NIR range.
