Metal halide perovskite nanostructures have emerged as low-dimensional semiconductors of great significance in many fields such as photovoltaics,photonics,and optoelectronics.Extensive efforts on the controlled synthe...Metal halide perovskite nanostructures have emerged as low-dimensional semiconductors of great significance in many fields such as photovoltaics,photonics,and optoelectronics.Extensive efforts on the controlled synthesis of perovskite nanostructures have been made towards potential device applications.The engineering of their band structures holds great promise in the rational tuning of the electronic and optical properties of perovskite nanostructures,which is one of the keys to achieving efficient and multifunctional optoelectronic devices.In this article,we summarize recent advances in band structure engineering of perovskite nanostructures.A survey of bandgap engineering of nanostructured perovskites is firstly presented from the aspects of dimensionality tailoring,compositional substitution,phase segregation and transition,as well as strain and pressure stimuli.The strategies of electronic doping are then reviewed,including defect-induced self-doping,inorganic or organic molecules-based chemical doping,and modification by metal ions or nanostructures.Based on the bandgap engineering and electronic doping,discussions on engineering energy band alignments in perovskite nanostructures are provided for building high-performance perovskite p-n junctions and heterostructures.At last,we provide our perspectives in engineering band structures of perovskite nanostructures towards future low-energy optoelectronics technologies.展开更多
High-performance infrared(IR)photodetectors made by low dimensional materials promise a wide range of applications in communication,security and biomedicine.Moreover,light-harvesting effects based on novel plasmonic m...High-performance infrared(IR)photodetectors made by low dimensional materials promise a wide range of applications in communication,security and biomedicine.Moreover,light-harvesting effects based on novel plasmonic materials and their combinations with two-dimensional(2 D)materials have raised tremendous interest in recent years,as they may potentially help the device complement or surpass currently commercialized IR photodetectors.Graphene is a particularly attractive plasmonic material because graphene plasmons are electrically tunable with a high degree of electromagnetic confinement in the mid-infrared(mid-IR)to terahertz regime and the field concentration can be further enhanced by forming nanostructures.Here,we report an efficient mid-IR room-temperature photodetector enhanced by plasmonic effect in graphene nanoresonators(GNRs)/graphene heterostructure.The plasmon polaritons in GNRs are size-dependent with strong field localization.Considering that the size and density of GNRs are controllable by chemical vapor deposition method,our work opens a cost-effective and scalable pathway to fabricate efficient IR optoelectronic devices with wavelength tunability.展开更多
LiBH_(4) and Mg(BH_(4))_(2) with high theoretical hydrogen mass capacity receive significant attentions for hy-drogen storage.Also,these compounds can be potentially applied as solid-state electrolytes with their high...LiBH_(4) and Mg(BH_(4))_(2) with high theoretical hydrogen mass capacity receive significant attentions for hy-drogen storage.Also,these compounds can be potentially applied as solid-state electrolytes with their high ionic conductivity.However,their applications are hindered by the poor kinetics and reversibility for hydrogen storage and low ionic conductivity at room temperature,respectively.To address these challenges,effective strategies towards engineering the hydrogen storage properties and the emerging solid-state electrolytes with improved performances have been summarized.The focuses are on the state-of-the-art developments of Li/Mg-based borohydrides with a parallel comparison of similar methods ap-plied in both hydrogen storage and solid-state electrolytes,particularly on the phase,structure,and thermal properties changes of Li/Mg-based borohydrides induced by milling,ion substitution,coordination,adding additives/catalysts,and hydrides.The similarities and differences between the strategies towards two kinds of applications are also discussed and prospected.The review will shed light on the future development of Li/Mg-based borohydrides for hydrogen storage and solid-state electrolytes.展开更多
Heavily doped colloidal plasmonic nanocrystals have attracted great attention because of their lower and adjustable free carrier densities and tunable localized surface plasmonic resonance bands in the spectral range ...Heavily doped colloidal plasmonic nanocrystals have attracted great attention because of their lower and adjustable free carrier densities and tunable localized surface plasmonic resonance bands in the spectral range from near-infra to mid-infra wavelengths.With its plasmon-enhanced optical nonlinearity,this new family of plasmonic materials shows a huge potential for nonlinear optical applications,such as ultrafast switching,nonlinear sensing,and pulse laser generation.Cu3-xP nanocrystals were previously shown to have a strong saturable absorption at the plasmonic resonance,which enabled high-energy Q-switched fiber lasers with 6.1μs pulse duration.This work demonstrates that both high-quality mode-locked and Q-switched pulses at 1560 nm can be generated by evanescently incorporating two-dimensional(2D)Cu3-xP nanocrystals onto a D-shaped optical fiber as an effective saturable absorber.The 3 dB bandwidth of the mode-locking optical spectrum is as broad as 7.3 nm,and the corresponding pulse duration can reach 423 fs.The repetition rate of the Q-switching pulses is higher than 80 kHz.Moreover,the largest pulse energy is more than 120μJ.Note that laser characteristics are highly stable and repeatable based on the results of over 20 devices.This work may trigger further investigations on heavily doped plasmonic 2D nanocrystals as a next-generation,inexpensive,and solution-processed element for fascinating photonics and optoelectronics applications.展开更多
The ultrafast monitoring of deoxyribonucleic acid(DNA)dynamic structural changes is an emerging and rapidly growing research topic in biotechnology.The existing optical spectroscopy used to identify different dynamica...The ultrafast monitoring of deoxyribonucleic acid(DNA)dynamic structural changes is an emerging and rapidly growing research topic in biotechnology.The existing optical spectroscopy used to identify different dynamical DNA structures lacks quick response while requiring large consumption of samples and bulky instrumental facilities.It is highly demanded to develop an ultrafast technique that monitors DNA structural changes with the external stimulus or cancer-related disease scenarios.Here,we demonstrate a novel photonic integrated graphene-optofluidic device to monitor DNA structural changes with the ultrafast response time.Our approach is featured with an effective and straightforward design of decoding the electronic structure change of graphene induced by its interactions with DNAs in different conformations using ultrafast nanosecond pulse laser and achieving refractive index sensitivity of~3×10^(−5) RIU.This innovative technique for the first time allows us to perform ultrafast monitoring of the conformational changes of special DNA molecules structures,including G-quadruplex formation by K+ions and i-motif formation by the low pH stimulus.The graphene-optofluidic device as presented here provides a new class of label-free,ultrafast,ultrasensitive,compact,and cost-effective optical biosensors for medical and healthcare applications.展开更多
基金support from Australian Research Council (ARC, FT150100450, IH150100006 and CE170100039)support from the MCATM and the FLEET+1 种基金the support from Shenzhen Nanshan District Pilotage Team Program (LHTD20170006)support from Guangzhou Science and Technology Program (Grant No. 201804010322)
文摘Metal halide perovskite nanostructures have emerged as low-dimensional semiconductors of great significance in many fields such as photovoltaics,photonics,and optoelectronics.Extensive efforts on the controlled synthesis of perovskite nanostructures have been made towards potential device applications.The engineering of their band structures holds great promise in the rational tuning of the electronic and optical properties of perovskite nanostructures,which is one of the keys to achieving efficient and multifunctional optoelectronic devices.In this article,we summarize recent advances in band structure engineering of perovskite nanostructures.A survey of bandgap engineering of nanostructured perovskites is firstly presented from the aspects of dimensionality tailoring,compositional substitution,phase segregation and transition,as well as strain and pressure stimuli.The strategies of electronic doping are then reviewed,including defect-induced self-doping,inorganic or organic molecules-based chemical doping,and modification by metal ions or nanostructures.Based on the bandgap engineering and electronic doping,discussions on engineering energy band alignments in perovskite nanostructures are provided for building high-performance perovskite p-n junctions and heterostructures.At last,we provide our perspectives in engineering band structures of perovskite nanostructures towards future low-energy optoelectronics technologies.
基金support from the National Key Research&Development Program(No.2016YFA0201902,2018YFA0703200)Shenzhen Nanshan District Pilotage Team Program(LHTD20170006)+4 种基金National Natural Science Foundation of China(61974099 and 61604102,51773041,61890940)Shanghai Committee of Science and Technology in China(18ZR1404900)Natural Science Research Project for Anhui Universities(Grant No.KJ2019A0596)Youth Project of Provincial Natural Science Foundation of Anhui(Grant No.2008085QF319)Australian Research Council(ARC,FT150100450 and IH150100006)。
文摘High-performance infrared(IR)photodetectors made by low dimensional materials promise a wide range of applications in communication,security and biomedicine.Moreover,light-harvesting effects based on novel plasmonic materials and their combinations with two-dimensional(2 D)materials have raised tremendous interest in recent years,as they may potentially help the device complement or surpass currently commercialized IR photodetectors.Graphene is a particularly attractive plasmonic material because graphene plasmons are electrically tunable with a high degree of electromagnetic confinement in the mid-infrared(mid-IR)to terahertz regime and the field concentration can be further enhanced by forming nanostructures.Here,we report an efficient mid-IR room-temperature photodetector enhanced by plasmonic effect in graphene nanoresonators(GNRs)/graphene heterostructure.The plasmon polaritons in GNRs are size-dependent with strong field localization.Considering that the size and density of GNRs are controllable by chemical vapor deposition method,our work opens a cost-effective and scalable pathway to fabricate efficient IR optoelectronic devices with wavelength tunability.
基金H.S.acknowledges the Guangdong-Hong Kong-Macao Joint Laboratory (Grant No.2019B121205001),Macao Sci-ence and Technology Development Fund (FDCT) (Project No.0098/2020/A2),National Key Research and Development Program (No.2022YFE0206400),Natural Science Foundation of Guang-dong Province (No.2023A1515010765)and FDCT-MOST joint project (Grant No.0026/2022/AMJ)for funding.We also acknowl-edge the support of the National Natural Science Foundation of China (Grant No.52104309)Natural Science Foundation of Hubei Province (No.2021CFB011)+1 种基金“Macao Young Scholars Program”China (No.AM2020004)FDCT Funding Scheme for Postdoctoral Researchers (No.0026/APD/2021).
文摘LiBH_(4) and Mg(BH_(4))_(2) with high theoretical hydrogen mass capacity receive significant attentions for hy-drogen storage.Also,these compounds can be potentially applied as solid-state electrolytes with their high ionic conductivity.However,their applications are hindered by the poor kinetics and reversibility for hydrogen storage and low ionic conductivity at room temperature,respectively.To address these challenges,effective strategies towards engineering the hydrogen storage properties and the emerging solid-state electrolytes with improved performances have been summarized.The focuses are on the state-of-the-art developments of Li/Mg-based borohydrides with a parallel comparison of similar methods ap-plied in both hydrogen storage and solid-state electrolytes,particularly on the phase,structure,and thermal properties changes of Li/Mg-based borohydrides induced by milling,ion substitution,coordination,adding additives/catalysts,and hydrides.The similarities and differences between the strategies towards two kinds of applications are also discussed and prospected.The review will shed light on the future development of Li/Mg-based borohydrides for hydrogen storage and solid-state electrolytes.
基金the support from the National Key Research&Development Program(No.2016YFA0201902)Shenzhen Nanshan District Pilotage Team Program(No.LHTD20170006)+1 种基金Australian Research Council(ARC,FT 150100450,IH150100006,and CE170100039)the funding support from China Postdoctoral Science Foundation Grant(No.217M622758).
文摘Heavily doped colloidal plasmonic nanocrystals have attracted great attention because of their lower and adjustable free carrier densities and tunable localized surface plasmonic resonance bands in the spectral range from near-infra to mid-infra wavelengths.With its plasmon-enhanced optical nonlinearity,this new family of plasmonic materials shows a huge potential for nonlinear optical applications,such as ultrafast switching,nonlinear sensing,and pulse laser generation.Cu3-xP nanocrystals were previously shown to have a strong saturable absorption at the plasmonic resonance,which enabled high-energy Q-switched fiber lasers with 6.1μs pulse duration.This work demonstrates that both high-quality mode-locked and Q-switched pulses at 1560 nm can be generated by evanescently incorporating two-dimensional(2D)Cu3-xP nanocrystals onto a D-shaped optical fiber as an effective saturable absorber.The 3 dB bandwidth of the mode-locking optical spectrum is as broad as 7.3 nm,and the corresponding pulse duration can reach 423 fs.The repetition rate of the Q-switching pulses is higher than 80 kHz.Moreover,the largest pulse energy is more than 120μJ.Note that laser characteristics are highly stable and repeatable based on the results of over 20 devices.This work may trigger further investigations on heavily doped plasmonic 2D nanocrystals as a next-generation,inexpensive,and solution-processed element for fascinating photonics and optoelectronics applications.
基金from the National Natural Science Foundation of China(21874096,21575095,51602305,61604102 and 61875139)the 111 Project,and the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+2 种基金the China Postdoctoral Science Foundation(2018M633118)Shenzhen Nanshan District Pilotage Team Program(LHTD20170006)Australian Research Council(ARC,FT150100450,IH150100006 and CE170100039).Q.Bao acknowledges support from the Australian Research Council(ARC)Centre of Excellence in Future Low-Energy Electronics Technologies(FLEET).
文摘The ultrafast monitoring of deoxyribonucleic acid(DNA)dynamic structural changes is an emerging and rapidly growing research topic in biotechnology.The existing optical spectroscopy used to identify different dynamical DNA structures lacks quick response while requiring large consumption of samples and bulky instrumental facilities.It is highly demanded to develop an ultrafast technique that monitors DNA structural changes with the external stimulus or cancer-related disease scenarios.Here,we demonstrate a novel photonic integrated graphene-optofluidic device to monitor DNA structural changes with the ultrafast response time.Our approach is featured with an effective and straightforward design of decoding the electronic structure change of graphene induced by its interactions with DNAs in different conformations using ultrafast nanosecond pulse laser and achieving refractive index sensitivity of~3×10^(−5) RIU.This innovative technique for the first time allows us to perform ultrafast monitoring of the conformational changes of special DNA molecules structures,including G-quadruplex formation by K+ions and i-motif formation by the low pH stimulus.The graphene-optofluidic device as presented here provides a new class of label-free,ultrafast,ultrasensitive,compact,and cost-effective optical biosensors for medical and healthcare applications.