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
Transition metal dichalcogenide(TMD)layered semiconductors possess immense potential in the design of photonic,electronic,optoelectronic,and sensor devices.However,the sub-bandgap light absorption of TMD in the range ...Transition metal dichalcogenide(TMD)layered semiconductors possess immense potential in the design of photonic,electronic,optoelectronic,and sensor devices.However,the sub-bandgap light absorption of TMD in the range from near-infrared(NIR)to short-wavelength infrared(SWIR)is insufficient for applications beyond the bandgap limit.Herein,we report that the sub-bandgap photoresponse of MoS_(2)/Au heterostructures can be robustly modulated by the electrode fabrication method employed.We observed up to 60%sub-bandgap absorption in the MoS_(2)/Au heterostructure,which includes the hybridized interface,where the Au layer was applied via sputter deposition.The greatly enhanced absorption of sub-bandgap light is due to the planar cavity formed by MoS_(2) and Au;as such,the absorption spectrum can be tuned by altering the thickness of the MoS_(2) layer.Photocurrent in the SWIR wavelength range increases due to increased absorption,which means that broad wavelength detection from visible toward SWIR is possible.We also achieved rapid photoresponse(~150μs)and high responsivity(17 mA W^(-1))at an excitation wavelength of 1550nm.Our findings demonstrate a facile method for optical property modulation using metal electrode engineering and for realizing SWIR photodetection in wide-bandgap 2D materials.展开更多
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supported by the Institute for Basic Science of Korea(IBS-R011-D1)the National Research Foundation of Korea(NRF)Grants(RS-2023-00246477)Korea Institute of Science and Technology(KIST)Institutional Program(2E32570 and 2E32571).
文摘Transition metal dichalcogenide(TMD)layered semiconductors possess immense potential in the design of photonic,electronic,optoelectronic,and sensor devices.However,the sub-bandgap light absorption of TMD in the range from near-infrared(NIR)to short-wavelength infrared(SWIR)is insufficient for applications beyond the bandgap limit.Herein,we report that the sub-bandgap photoresponse of MoS_(2)/Au heterostructures can be robustly modulated by the electrode fabrication method employed.We observed up to 60%sub-bandgap absorption in the MoS_(2)/Au heterostructure,which includes the hybridized interface,where the Au layer was applied via sputter deposition.The greatly enhanced absorption of sub-bandgap light is due to the planar cavity formed by MoS_(2) and Au;as such,the absorption spectrum can be tuned by altering the thickness of the MoS_(2) layer.Photocurrent in the SWIR wavelength range increases due to increased absorption,which means that broad wavelength detection from visible toward SWIR is possible.We also achieved rapid photoresponse(~150μs)and high responsivity(17 mA W^(-1))at an excitation wavelength of 1550nm.Our findings demonstrate a facile method for optical property modulation using metal electrode engineering and for realizing SWIR photodetection in wide-bandgap 2D materials.