Micro-light-emitting diodes(μ-LEDs)are regarded as the cornerstone of next-generation display technology to meet the personalised demands of advanced applications,such as mobile phones,wearable watches,virtual/augmen...Micro-light-emitting diodes(μ-LEDs)are regarded as the cornerstone of next-generation display technology to meet the personalised demands of advanced applications,such as mobile phones,wearable watches,virtual/augmented reality,micro-projectors and ultrahigh-definition TVs.However,as the LED chip size shrinks to below 20μm,conventional phosphor colour conversion cannot present sufficient luminance and yield to support highresolution displays due to the low absorption cross-section.The emergence of quantum dot(QD)materials is expected to fill this gap due to their remarkable photoluminescence,narrow bandwidth emission,colour tuneability,high quantum yield and nanoscale size,providing a powerful full-colour solution for μ-LED displays.Here,we comprehensively review the latest progress concerning the implementation of μ-LEDs and QDs in display technology,including μ-LED design and fabrication,large-scale μ-LED transfer and QD full-colour strategy.Outlooks on QD stability,patterning and deposition and challenges of μ-LED displays are also provided.Finally,we discuss the advanced applications of QD-based μ-LED displays,showing the bright future of this technology.展开更多
Halide perovskites,such as methylammonium lead halide perovskites(MAPbX3,X=I,Br,and Cl),are emerging as promising candidates for a wide range of optoelectronic applications,including solar cells,light-emitting diodes,...Halide perovskites,such as methylammonium lead halide perovskites(MAPbX3,X=I,Br,and Cl),are emerging as promising candidates for a wide range of optoelectronic applications,including solar cells,light-emitting diodes,and photodetectors,due to their superior optoelectronic properties.All-inorganic lead halide perovskites CsPbX3 are attracting a lot of attention because replacing the organic cations with Cs+enhances the stability,and its halide-mixing derivatives offer broad bandgap tunability covering nearly the entire visible spectrum.However,there is evidence suggesting that the optical properties of mixed-halide perovskites are influenced by phase segregation under external stimuli,especially illumination,which may negatively impact the performance of optoelectronic devices.It is reported that the mixed-halide perovskites in forms of thin films and nanocrystals are segregated into a low-bandgap I-rich phase and a high-bandgap Br-rich phase.Herein,we present a critical review on the synthesis and basic properties of all-inorganic perovskites,phase-segregation phenomena,plausible mechanisms,and methods to mitigate phase segregation,providing insights on advancing mixed-halide perovskite optoelectronics with reliable performance.展开更多
We propose a flexible white-light system for high-speed visible-light communication(VLC)applications,which consists of a semipolar blue InGaN/GaN single-quantum-well micro-light-emitting diode(LED)on a flexible substr...We propose a flexible white-light system for high-speed visible-light communication(VLC)applications,which consists of a semipolar blue InGaN/GaN single-quantum-well micro-light-emitting diode(LED)on a flexible substrate pumping green CsPbBr3 perovskite quantum-dot(PQD)paper in nanostructure form and red CdSe QD paper.The highest bandwidth for CsPbBr3 PQD paper,229 MHz,is achieved with a blue micro-LED pumping source and a high data transmission rate of 400 Mbps;this is very promising for VLC application.An 817 MHz maximum bandwidth and a 1.5 Gbps transmission speed are attained by the proposed semipolar blue micro-LEDs.The proposed flexible white light system and the high-bandwidth PQD paper could pave the way for VLC wearable devices.展开更多
Neuromorphic vision sensors have been extremely beneficial in developing energy-efficient intelligent systems for robotics and privacy-preserving security applications.There is a dire need for devices to mimic the ret...Neuromorphic vision sensors have been extremely beneficial in developing energy-efficient intelligent systems for robotics and privacy-preserving security applications.There is a dire need for devices to mimic the retina's photoreceptors that encode the light illumination into a sequence of spikes to develop such sensors.Herein,we develop a hybrid perovskite-based flexible photoreceptor whose capacitance changes proportionally to the light intensity mimicking the retina's rod cells,paving the way for developing an efficient artificial retina network.The proposed device constitutes a hybrid nanocomposite of perovskites(methyl-ammonium lead bromide)and the ferroelectric terpolymer(polyvinylidene fluoride trifluoroethylene-chlorofluoroethylene).A metal-insulator-metal type capacitor with the prepared composite exhibits the unique and photosensitive capacitive behavior at various light intensities in the visible light spectrum.The proposed photoreceptor mimics the spectral sensitivity curve of human photopic vision.The hybrid nanocomposite is stable in ambient air for 129 weeks,with no observable degradation of the composite due to the encapsulation of hybrid perovskites in the hydrophobic polymer.The functionality of the proposed photoreceptor to recognize handwritten digits(MNIST)dataset using an unsupervised trained spiking neural network with 72.05%recognition accuracy is demonstrated.This demonstration proves the potential of the proposed sensor for neuromorphic vision applications.展开更多
基金the financial support of Shenzhen Peacock Team funding(KQTD20170810110313773)financial support from the Australian Research Council(ARC)(DP190103316)+1 种基金financial support from the Taiwan science and technology authority,China(107-2221-E-009-113-MY3)financial support from the startup funding of City University of Hong Kong.
文摘Micro-light-emitting diodes(μ-LEDs)are regarded as the cornerstone of next-generation display technology to meet the personalised demands of advanced applications,such as mobile phones,wearable watches,virtual/augmented reality,micro-projectors and ultrahigh-definition TVs.However,as the LED chip size shrinks to below 20μm,conventional phosphor colour conversion cannot present sufficient luminance and yield to support highresolution displays due to the low absorption cross-section.The emergence of quantum dot(QD)materials is expected to fill this gap due to their remarkable photoluminescence,narrow bandwidth emission,colour tuneability,high quantum yield and nanoscale size,providing a powerful full-colour solution for μ-LED displays.Here,we comprehensively review the latest progress concerning the implementation of μ-LEDs and QDs in display technology,including μ-LED design and fabrication,large-scale μ-LED transfer and QD full-colour strategy.Outlooks on QD stability,patterning and deposition and challenges of μ-LED displays are also provided.Finally,we discuss the advanced applications of QD-based μ-LED displays,showing the bright future of this technology.
基金Australian Research Council(DP190103316)UNSW SHARP Project(RG163043)+1 种基金US Office of Naval Research(N00014-18-1-2408)US National Science Foundation(CMMI-1930809).
文摘Halide perovskites,such as methylammonium lead halide perovskites(MAPbX3,X=I,Br,and Cl),are emerging as promising candidates for a wide range of optoelectronic applications,including solar cells,light-emitting diodes,and photodetectors,due to their superior optoelectronic properties.All-inorganic lead halide perovskites CsPbX3 are attracting a lot of attention because replacing the organic cations with Cs+enhances the stability,and its halide-mixing derivatives offer broad bandgap tunability covering nearly the entire visible spectrum.However,there is evidence suggesting that the optical properties of mixed-halide perovskites are influenced by phase segregation under external stimuli,especially illumination,which may negatively impact the performance of optoelectronic devices.It is reported that the mixed-halide perovskites in forms of thin films and nanocrystals are segregated into a low-bandgap I-rich phase and a high-bandgap Br-rich phase.Herein,we present a critical review on the synthesis and basic properties of all-inorganic perovskites,phase-segregation phenomena,plausible mechanisms,and methods to mitigate phase segregation,providing insights on advancing mixed-halide perovskite optoelectronics with reliable performance.
基金Ministry of Science and Technology,Taiwan(108-2221-E-009-113-MY3,110-2124-M-A49-003-)National Natural Science Foundation of China(11904302)Major Science and Technology Project of Xiamen(3502Z20191015)。
文摘We propose a flexible white-light system for high-speed visible-light communication(VLC)applications,which consists of a semipolar blue InGaN/GaN single-quantum-well micro-light-emitting diode(LED)on a flexible substrate pumping green CsPbBr3 perovskite quantum-dot(PQD)paper in nanostructure form and red CdSe QD paper.The highest bandwidth for CsPbBr3 PQD paper,229 MHz,is achieved with a blue micro-LED pumping source and a high data transmission rate of 400 Mbps;this is very promising for VLC application.An 817 MHz maximum bandwidth and a 1.5 Gbps transmission speed are attained by the proposed semipolar blue micro-LEDs.The proposed flexible white light system and the high-bandwidth PQD paper could pave the way for VLC wearable devices.
文摘Neuromorphic vision sensors have been extremely beneficial in developing energy-efficient intelligent systems for robotics and privacy-preserving security applications.There is a dire need for devices to mimic the retina's photoreceptors that encode the light illumination into a sequence of spikes to develop such sensors.Herein,we develop a hybrid perovskite-based flexible photoreceptor whose capacitance changes proportionally to the light intensity mimicking the retina's rod cells,paving the way for developing an efficient artificial retina network.The proposed device constitutes a hybrid nanocomposite of perovskites(methyl-ammonium lead bromide)and the ferroelectric terpolymer(polyvinylidene fluoride trifluoroethylene-chlorofluoroethylene).A metal-insulator-metal type capacitor with the prepared composite exhibits the unique and photosensitive capacitive behavior at various light intensities in the visible light spectrum.The proposed photoreceptor mimics the spectral sensitivity curve of human photopic vision.The hybrid nanocomposite is stable in ambient air for 129 weeks,with no observable degradation of the composite due to the encapsulation of hybrid perovskites in the hydrophobic polymer.The functionality of the proposed photoreceptor to recognize handwritten digits(MNIST)dataset using an unsupervised trained spiking neural network with 72.05%recognition accuracy is demonstrated.This demonstration proves the potential of the proposed sensor for neuromorphic vision applications.
