AlGaInP-based red miniaturized light-emitting diode(mini-LED)is a key component in realizing a full-color display.One of the main obstacles originates from interfacial recombination at the AlGaInP-SiO_(2)interface,and...AlGaInP-based red miniaturized light-emitting diode(mini-LED)is a key component in realizing a full-color display.One of the main obstacles originates from interfacial recombination at the AlGaInP-SiO_(2)interface,and it is crucial to develop effective surface passivation strategies to achieve higher external quantum efficiency(EQE)in AlGaInP-based red mini-LEDs.Here,we demonstrated AlGaInP-based red flip-chip mini-LEDs with an AlN passivation layer via atomic layer deposition(ALD).Utilizing a Monte Carlo ray tracing method,we investigated the effects of the SiO_(2)passivation layer and the Al N passivation layer on the optical performances of mini-LEDs.Since the refractive index of AlN is between AlGaInP and SiO_(2),the total internal reflection is alleviated and light extraction is enhanced.Unexpectedly,the AlN passivation layer also contributes to improving the current spreading ability of mini-LEDs,which is demonstrated by the near-field light distribution.Benefiting from superior light extraction and improved current spreading,the EQE of the mini-LED with an AlN passivation layer realizes an increment of 16.1%at 5 mA,in comparison to the mini-LED with a SiO_(2)passivation layer.The EQE of miniLEDs with an AlN passivation layer reaches a competitive value of 22.3%at 5 mA,surpassing previously reported AlGaInPbased red mini-LEDs.Moreover,the high temperature-humidity aging test exhibits that the AlN passivation layer effectively enhances the reliability of mini-LEDs.This work provides guidance for high-performance AlGaInP-based red flip-chip miniLEDs design and manufacture.展开更多
Mini-LED backlights,combining color conversion materials with blue mini-LED chips,promise traditional liquid crystal displays(LCDs)with higher luminance,better contrast,and a wider color gamut.However,as color convers...Mini-LED backlights,combining color conversion materials with blue mini-LED chips,promise traditional liquid crystal displays(LCDs)with higher luminance,better contrast,and a wider color gamut.However,as color conversion materials,quantum dots(QDs)are toxic and unstable,whereas commercially available inorganic phosphors are too big in size to combine with small mini-LED chips and also have strong size-dependence of quantum efficiency(QE)and reliability.In this work,we prepare fine-grained Sr_(2)Si_(5)N_(8):Eu^(2+)-based red phosphors with high efficiency and stability by treating commercially available phosphors with ball milling,centrifuging,and acid washing.The particle size of phosphors can be easily controlled by milling speed,and the phosphors with a size varying from 3.5 to 0.7 mm are thus obtained.The samples remain the same QE as the original ones(~80%)even when their particle size is reduced to 3.2-3.5 mm,because they contain fewer surface suspension bond defects.More importantly,SrBaSi_(5)N_(8):Eu^(2+)phosphors show a size-independent thermal quenching behavior and a zero thermal degradation.We demonstrate that red-emitting mini-LEDs can be fabricated by combining the SrBaSi_(5)N_(8):Eu^(2+)red phosphor(3.5 mm in size)with blue mini-LED chips,which show a high external quantum efficiency(EQE)of above 31%and a super-high luminance of 34.3 Mnits.It indicates that fine and high efficiency phosphors can be obtained by the proposed method in this work,and they have great potentials for use in mini-LED displays.展开更多
Mini light-emitting diodes(Mini-LEDs)show great application potential in high-end displays owing to their superior pixel density,brightness,responsiveness,and efficiency.However,current packaging materials for Mini-LE...Mini light-emitting diodes(Mini-LEDs)show great application potential in high-end displays owing to their superior pixel density,brightness,responsiveness,and efficiency.However,current packaging materials for Mini-LEDs are predominantly thermally cured,which is energy-and time-consuming and can adversely affect electronic components.In this study,a novel UV-curable silicone resin containing phenyl,disulfide,and acryloyl groups(SPASR)is developed from commercially available siloxanes.The resin exhibits a refractive index(n_(d))higher than 1.5,and it can be cured within 30 s under UV irradiation.After curing,it exhibits an optical transparency exceeding 92%,a lap adhesion strength of up to1.84 MPa,and good thermostability(T_(5%)>265℃).Notably,the volume shrinkage is less than 4.83%,attributed to the release of photopolymerization stress via UV-induced disulfide metathesis during UV curing.Mini-LEDs encapsulated with this resin show luminescence properties comparable to those of conventional thermally-cured sealants,and show excellent sealability wihtout visible penetration after being immersed in red ink for 12 h.Consequently,these excellent properties make the SPASR resin an ideal candidate for microelectronic encapsulation,offering a more reliable and efficient solution for the electronics industry.展开更多
基金supported by the Wuhan Joint Innovation Laboratory of Advanced Display Industry(Grant No.2024010902040449)the National Natural Science Foundation of China(Grant Nos.52075394,52475601)+4 种基金the National Key Research and Development Program of China(Grant Nos.2022YFB3603603,2021YFB3600204)the National Youth Talent Support Program,the Key Research and Development Program of Hubei Province(Grant No.2023BAB137)the Knowledge Innovation Program of Wuhan-Basic Research(Grant No.2023010201010068)the Science and Technology Major Project of Hubei Province(Grant No.2024BAA004)the Science and Technology Major Project of Wuhan(Grant No.2024010702020024)。
文摘AlGaInP-based red miniaturized light-emitting diode(mini-LED)is a key component in realizing a full-color display.One of the main obstacles originates from interfacial recombination at the AlGaInP-SiO_(2)interface,and it is crucial to develop effective surface passivation strategies to achieve higher external quantum efficiency(EQE)in AlGaInP-based red mini-LEDs.Here,we demonstrated AlGaInP-based red flip-chip mini-LEDs with an AlN passivation layer via atomic layer deposition(ALD).Utilizing a Monte Carlo ray tracing method,we investigated the effects of the SiO_(2)passivation layer and the Al N passivation layer on the optical performances of mini-LEDs.Since the refractive index of AlN is between AlGaInP and SiO_(2),the total internal reflection is alleviated and light extraction is enhanced.Unexpectedly,the AlN passivation layer also contributes to improving the current spreading ability of mini-LEDs,which is demonstrated by the near-field light distribution.Benefiting from superior light extraction and improved current spreading,the EQE of the mini-LED with an AlN passivation layer realizes an increment of 16.1%at 5 mA,in comparison to the mini-LED with a SiO_(2)passivation layer.The EQE of miniLEDs with an AlN passivation layer reaches a competitive value of 22.3%at 5 mA,surpassing previously reported AlGaInPbased red mini-LEDs.Moreover,the high temperature-humidity aging test exhibits that the AlN passivation layer effectively enhances the reliability of mini-LEDs.This work provides guidance for high-performance AlGaInP-based red flip-chip miniLEDs design and manufacture.
基金This work is supported by the National Natural Science Foundation of China(Nos.51832005 and 52172157)the Fundamental Research Funds for the Central Universities(No.20720200075)Fujian Provincial Science and Technology Project(Nos.2020I0002 and 2021J01042).
文摘Mini-LED backlights,combining color conversion materials with blue mini-LED chips,promise traditional liquid crystal displays(LCDs)with higher luminance,better contrast,and a wider color gamut.However,as color conversion materials,quantum dots(QDs)are toxic and unstable,whereas commercially available inorganic phosphors are too big in size to combine with small mini-LED chips and also have strong size-dependence of quantum efficiency(QE)and reliability.In this work,we prepare fine-grained Sr_(2)Si_(5)N_(8):Eu^(2+)-based red phosphors with high efficiency and stability by treating commercially available phosphors with ball milling,centrifuging,and acid washing.The particle size of phosphors can be easily controlled by milling speed,and the phosphors with a size varying from 3.5 to 0.7 mm are thus obtained.The samples remain the same QE as the original ones(~80%)even when their particle size is reduced to 3.2-3.5 mm,because they contain fewer surface suspension bond defects.More importantly,SrBaSi_(5)N_(8):Eu^(2+)phosphors show a size-independent thermal quenching behavior and a zero thermal degradation.We demonstrate that red-emitting mini-LEDs can be fabricated by combining the SrBaSi_(5)N_(8):Eu^(2+)red phosphor(3.5 mm in size)with blue mini-LED chips,which show a high external quantum efficiency(EQE)of above 31%and a super-high luminance of 34.3 Mnits.It indicates that fine and high efficiency phosphors can be obtained by the proposed method in this work,and they have great potentials for use in mini-LED displays.
基金financially supported by the National Natural Science Foundation of China(No.52273104)。
文摘Mini light-emitting diodes(Mini-LEDs)show great application potential in high-end displays owing to their superior pixel density,brightness,responsiveness,and efficiency.However,current packaging materials for Mini-LEDs are predominantly thermally cured,which is energy-and time-consuming and can adversely affect electronic components.In this study,a novel UV-curable silicone resin containing phenyl,disulfide,and acryloyl groups(SPASR)is developed from commercially available siloxanes.The resin exhibits a refractive index(n_(d))higher than 1.5,and it can be cured within 30 s under UV irradiation.After curing,it exhibits an optical transparency exceeding 92%,a lap adhesion strength of up to1.84 MPa,and good thermostability(T_(5%)>265℃).Notably,the volume shrinkage is less than 4.83%,attributed to the release of photopolymerization stress via UV-induced disulfide metathesis during UV curing.Mini-LEDs encapsulated with this resin show luminescence properties comparable to those of conventional thermally-cured sealants,and show excellent sealability wihtout visible penetration after being immersed in red ink for 12 h.Consequently,these excellent properties make the SPASR resin an ideal candidate for microelectronic encapsulation,offering a more reliable and efficient solution for the electronics industry.
