Despite great progress in developing mode-selective light emission technologies based on self-emitting materials,few rewritable displays with modeselective multiple light emissions have been demonstrated.Herein,we pre...Despite great progress in developing mode-selective light emission technologies based on self-emitting materials,few rewritable displays with modeselective multiple light emissions have been demonstrated.Herein,we present a rewritable triple-mode light-emitting display enabled by stimuli-interactive fluorescence(FL),room-temperature phosphorescence(RTP),and electroluminescence(EL).The display comprises coplanar electrodes separated by a gap,a polymer composite with FL inorganic phosphors(EL/FL layer),and a polymer composite with solvent-responsive RTP additives(RTP layer).Upon 254 nm UV exposure,a dual-mode emission of RTP and FL occurs from the RTP and EL/FL layers,respectively.When a polar liquid,besides water,is applied on the display and an AC field is applied between the coplanar electrodes,EL from the EL/FL layer is triggered,and the display operates in a triple mode.Interestingly,when water is applied to the display,the RTP mode is deactivated,rendering the display to operate in a dual mode of FL and EL.By manipulating the evaporation of the applied polar liquids and water,the mode-selective light emission of FL,RTP,and EL is rewritable in the triple-mode display.Additionally,a high-security full-color information encryption display is demonstrated,wherein the information of digital numbers,letters,and Morse code encoded in one optical mode is only deciphered when properly matched with that encoded in the other two modes.Thus,this article outlines a strategy to fulfill the substantial demand for high-security personalized information based on room-temperature multi-light-emitting displays.展开更多
Perovskite light-emitting diodes(PeLEDs)are considered as promising candidates for nextgeneration solution-processed full-color displays.However,the external quantum efficiencies(EQEs)and operational stabilities of de...Perovskite light-emitting diodes(PeLEDs)are considered as promising candidates for nextgeneration solution-processed full-color displays.However,the external quantum efficiencies(EQEs)and operational stabilities of deep-blue(<460 nm)PeLEDs still lag far behind their red and green counterparts.Herein,a rapid crystallization method based on hot-antisolvent bathing is proposed for realization of deep-blue PeLEDs.By promoting immediate removal of the precursor solvent from the wet perovskite films,development of the quasi-two-dimensional(2D)Ruddlesden–Popper perovskite(2D-RPP)crystals with n values>3 is hampered completely,so that phase-pure 2D-RPP films with bandgaps suitable for deep-blue PeLEDs can be obtained successfully.The uniquely developed rapid crystallization method also enables formation of randomly oriented 2D-RPP crystals,thereby improving the transfer and transport kinetics of the charge carriers.Thus,high-performance deep-blue PeLEDs emitting at 437 nm with a peak EQE of 0.63%are successfully demonstrated.The color coordinates are confirmed to be(0.165,0.044),which match well with the Rec.2020 standard blue gamut and have excellent spectral stability.展开更多
Two-dimensional(2D)materials have recently provided a new perspective on optoelectronics because of their unique layered structure and excellent physical properties.However,their potential use as optoelectric devices ...Two-dimensional(2D)materials have recently provided a new perspective on optoelectronics because of their unique layered structure and excellent physical properties.However,their potential use as optoelectric devices has been limited by the trade-off between photoresponsivity and response time.Here,based on a vertically stacked atomically thin p-n junction,we propose a gap-mode plasmon structure that simultaneously enables enhanced responsivity and rapid photodetection.The atomically thin 2D materials act as a spacer for enhancing the gap-mode plasmons,and their short transit length in the vertical direction allows fast photocarrier transport.We demonstrate a high responsivity of up to 8.67 A/W with a high operation speed that exceeds 35 MHz under a 30 nW laser power.Spectral photocurrent,absorption,and a numerical simulation are used to verify the effectiveness of the gap-mode plasmons in the device.We believe that the design strategy proposed in this study can pave the way for a platform to overcome the trade-off between responsivity and response time.展开更多
Inkjet printing of two-dimensional(2D)transition metal dichalcogenide(TMD)nanosheets fabricated by liquid-phase exfoliation(LPE)allows simple,mass-producible,and low-cost photo-electronic devices.Many LPE processes in...Inkjet printing of two-dimensional(2D)transition metal dichalcogenide(TMD)nanosheets fabricated by liquid-phase exfoliation(LPE)allows simple,mass-producible,and low-cost photo-electronic devices.Many LPE processes involve toxic and environmentally hazardous solvents;however,dispersants have restricted the extent of applications of 2D-TMD inks.Herein,various 2D-TMD nanosheets,including MoS2,MoSe2,WS2,and WSe2,in addition to few-layered graphene,are inkjet-printed using a LPE process based on zwitterionic dispersants in water.Zwitterions with cationic and anionic species are water-soluble,while alkyl chain moieties associated with two ionic species adhere universally on the surface of TMD nanosheets,resulting in high throughput liquid exfoliation of the nanosheets.The zwitterion-assisted TMD nanosheets in water are successtully employed as an ink without the need for additives to adjust the viscosity and surface tension of the ink for use in an office inkjet printer;this gives rise to A4 scale,large-area inkjet-printed images on diverse substrates,such as metals,oxides,and polymer substrates patchable onto human skin.Combination with conductive graphene nanosheet inks allowed the development of mechanically flexible,biocompatible-printed arrays of photodetectors with pixelated MoSe2 channels on a paper exhibiting a photocurrent ON/OFF ratio of approximately 1038 and photocurrent switching of 500 ms.展开更多
Optical encryption technologies based on room-temperature light-emitting materials are of considerable interest.Herein,we present three-dimensional(3D)printable dual-light-emitting materials for high-performance optic...Optical encryption technologies based on room-temperature light-emitting materials are of considerable interest.Herein,we present three-dimensional(3D)printable dual-light-emitting materials for high-performance optical pattern encryption.These are based on fluorescent perovskite nanocrystals(NCs)embedded in metal-organic frameworks(MOFs)designed for phosphorescent host-vip interactions.Notably,perovskite-containing MOFs emit a highly efficient blue phosphorescence,and perovskite NCs embedded in the MOFs emit characteristic green or red fluorescence under ultraviolet(UV)irradiation.Such dual-light-emitting MOFs with independent fluorescence and phosphorescence emissions are employed in pochoir pattern encryption,wherein actual information with transient phosphorescence is efficiently concealed behind fake information with fluorescence under UV exposure.Moreover,a 3D cubic skeleton is developed with the dual-light-emitting MOF powder dispersed in 3D-printable polymer filaments for 3D dual-pattern encryption.This article outlines a universal principle for developing MOF-based room-temperature multi-light-emitting materials and a strategy for multidimensional information encryption with enhanced capacity and security.展开更多
基金supported by the Creative Materials Discovery Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(MSIT)(2022M3C1A3081211)This study was also supported by a grant from the NRF funded by MSIT(RS-2023-00208577)+1 种基金This study was financially supported by the Nano&Material Technology Development Program through the NRF funded by MSIT(RS-2024-00451891 and RS-2024-00416938)by the Open Resource Research Program of the Korea Institute of Science and Technology(2E32961).
文摘Despite great progress in developing mode-selective light emission technologies based on self-emitting materials,few rewritable displays with modeselective multiple light emissions have been demonstrated.Herein,we present a rewritable triple-mode light-emitting display enabled by stimuli-interactive fluorescence(FL),room-temperature phosphorescence(RTP),and electroluminescence(EL).The display comprises coplanar electrodes separated by a gap,a polymer composite with FL inorganic phosphors(EL/FL layer),and a polymer composite with solvent-responsive RTP additives(RTP layer).Upon 254 nm UV exposure,a dual-mode emission of RTP and FL occurs from the RTP and EL/FL layers,respectively.When a polar liquid,besides water,is applied on the display and an AC field is applied between the coplanar electrodes,EL from the EL/FL layer is triggered,and the display operates in a triple mode.Interestingly,when water is applied to the display,the RTP mode is deactivated,rendering the display to operate in a dual mode of FL and EL.By manipulating the evaporation of the applied polar liquids and water,the mode-selective light emission of FL,RTP,and EL is rewritable in the triple-mode display.Additionally,a high-security full-color information encryption display is demonstrated,wherein the information of digital numbers,letters,and Morse code encoded in one optical mode is only deciphered when properly matched with that encoded in the other two modes.Thus,this article outlines a strategy to fulfill the substantial demand for high-security personalized information based on room-temperature multi-light-emitting displays.
基金National R&D Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(Grant Nos.2018M3D1A1058793 and 2021R1A3B1068920)the Yonsei Signature Research Cluster Program of 2021(Grant No.2021-22-0002).
文摘Perovskite light-emitting diodes(PeLEDs)are considered as promising candidates for nextgeneration solution-processed full-color displays.However,the external quantum efficiencies(EQEs)and operational stabilities of deep-blue(<460 nm)PeLEDs still lag far behind their red and green counterparts.Herein,a rapid crystallization method based on hot-antisolvent bathing is proposed for realization of deep-blue PeLEDs.By promoting immediate removal of the precursor solvent from the wet perovskite films,development of the quasi-two-dimensional(2D)Ruddlesden–Popper perovskite(2D-RPP)crystals with n values>3 is hampered completely,so that phase-pure 2D-RPP films with bandgaps suitable for deep-blue PeLEDs can be obtained successfully.The uniquely developed rapid crystallization method also enables formation of randomly oriented 2D-RPP crystals,thereby improving the transfer and transport kinetics of the charge carriers.Thus,high-performance deep-blue PeLEDs emitting at 437 nm with a peak EQE of 0.63%are successfully demonstrated.The color coordinates are confirmed to be(0.165,0.044),which match well with the Rec.2020 standard blue gamut and have excellent spectral stability.
基金This work was supported by the National Research Foundation of Korea(NRF)through Basic Research Program(No.2019R1A2C2009171)Creative Materials Discovery Program(No.2016M3D1A1900035).
文摘Two-dimensional(2D)materials have recently provided a new perspective on optoelectronics because of their unique layered structure and excellent physical properties.However,their potential use as optoelectric devices has been limited by the trade-off between photoresponsivity and response time.Here,based on a vertically stacked atomically thin p-n junction,we propose a gap-mode plasmon structure that simultaneously enables enhanced responsivity and rapid photodetection.The atomically thin 2D materials act as a spacer for enhancing the gap-mode plasmons,and their short transit length in the vertical direction allows fast photocarrier transport.We demonstrate a high responsivity of up to 8.67 A/W with a high operation speed that exceeds 35 MHz under a 30 nW laser power.Spectral photocurrent,absorption,and a numerical simulation are used to verify the effectiveness of the gap-mode plasmons in the device.We believe that the design strategy proposed in this study can pave the way for a platform to overcome the trade-off between responsivity and response time.
基金This research was supported by the Creative Materials Discovery Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Science and ICT(2018M3D1A1058536)This research was also supported by a grant from the NRF funded by the Korean government(MEST)(Nus.2017R1 A2A1A05001160 aurd 2016M3A7B4910530)Tlis work is based upon work supported by the Ministry of Trade,Industry&Energy(MOTTE,Korea)under Industrial Technology Innovation Program(No.10063274).
文摘Inkjet printing of two-dimensional(2D)transition metal dichalcogenide(TMD)nanosheets fabricated by liquid-phase exfoliation(LPE)allows simple,mass-producible,and low-cost photo-electronic devices.Many LPE processes involve toxic and environmentally hazardous solvents;however,dispersants have restricted the extent of applications of 2D-TMD inks.Herein,various 2D-TMD nanosheets,including MoS2,MoSe2,WS2,and WSe2,in addition to few-layered graphene,are inkjet-printed using a LPE process based on zwitterionic dispersants in water.Zwitterions with cationic and anionic species are water-soluble,while alkyl chain moieties associated with two ionic species adhere universally on the surface of TMD nanosheets,resulting in high throughput liquid exfoliation of the nanosheets.The zwitterion-assisted TMD nanosheets in water are successtully employed as an ink without the need for additives to adjust the viscosity and surface tension of the ink for use in an office inkjet printer;this gives rise to A4 scale,large-area inkjet-printed images on diverse substrates,such as metals,oxides,and polymer substrates patchable onto human skin.Combination with conductive graphene nanosheet inks allowed the development of mechanically flexible,biocompatible-printed arrays of photodetectors with pixelated MoSe2 channels on a paper exhibiting a photocurrent ON/OFF ratio of approximately 1038 and photocurrent switching of 500 ms.
基金supported by the Creative Materials Discovery Program and the Pioneer Research Center Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT&Future Planning(2018M3D1A1058536 and NRF-2022M3C1A3081211)supported by a grant from the National Research Foundation of Korea(NRF)funded by the Korean government(MEST)(No.RS-2023-00208577)+1 种基金supported by National R&D Program through the National Research Foundation of Korea funded by the Ministry of Science and ICT(2021M3H4A1A03047331)supported by the Open Resource Research Program of the Korea Institute of Science and Technology(2E31551).
文摘Optical encryption technologies based on room-temperature light-emitting materials are of considerable interest.Herein,we present three-dimensional(3D)printable dual-light-emitting materials for high-performance optical pattern encryption.These are based on fluorescent perovskite nanocrystals(NCs)embedded in metal-organic frameworks(MOFs)designed for phosphorescent host-vip interactions.Notably,perovskite-containing MOFs emit a highly efficient blue phosphorescence,and perovskite NCs embedded in the MOFs emit characteristic green or red fluorescence under ultraviolet(UV)irradiation.Such dual-light-emitting MOFs with independent fluorescence and phosphorescence emissions are employed in pochoir pattern encryption,wherein actual information with transient phosphorescence is efficiently concealed behind fake information with fluorescence under UV exposure.Moreover,a 3D cubic skeleton is developed with the dual-light-emitting MOF powder dispersed in 3D-printable polymer filaments for 3D dual-pattern encryption.This article outlines a universal principle for developing MOF-based room-temperature multi-light-emitting materials and a strategy for multidimensional information encryption with enhanced capacity and security.
