The surging demand and adoption of infrared photodetectors(IRPDs)in sectors of imaging,mobile,healthcare,automobiles,and optical communication are hindered by the prohibitive costs of traditional IRPD materials such a...The surging demand and adoption of infrared photodetectors(IRPDs)in sectors of imaging,mobile,healthcare,automobiles,and optical communication are hindered by the prohibitive costs of traditional IRPD materials such as InGaAs and HgCdTe.Quantum dots(QDs),especially lead chalcogenide(PbS)QDs,represent the next-generation lowbandgap semiconductors for near-infrared(NIR)detection due to their high optical absorption coefficient,tunable bandgap,low fabrication costs,and device compatibility.Innovative techniques such as ligand exchange processes have been proposed to boost the performance of PbS QDs photodetectors,mostly using short ligands like 1,2-ethanedithiol(EDT)and tetrabutylammonium iodide(TBAI).Our study explores the use of long-chain dithiol ligands to enhance the responsivity of PbS QDs/InGaZnO phototransistors.Long-chain dithiol ligands are found to suppress horizontal electron transport/leakage and electron trapping,which is beneficial for responsivity.Utilizing a novel ligand-exchange technique with 1,10-decanedithiol(DDT),we develop high-performance hybrid phototransistors with detectivity exceeding 10^(14) Jones.Based on these phototransistors,we demonstrate image communication through a NIR optical communication system.The long-ligand PbS QDs/InGaZnO hybrid phototransistor demonstrates significant potential for NIR low-dose imaging and optical communication,particularly in scenarios requiring the detection of weak light signals at low frequencies.展开更多
ABSTRACT The low flexural strength and high brittleness of cementitious materials impair their service life in building structures.In this study,we developed a new polymer-modified mortar by in situ polymerization of ...ABSTRACT The low flexural strength and high brittleness of cementitious materials impair their service life in building structures.In this study,we developed a new polymer-modified mortar by in situ polymerization of acrylamide(AM)monomers during the cement setting,which enhanced the flexural and durable performances of mortars.The mechanical properties,micro-and-pore structures,hydrated products,interactions between cement hydrates and polyacrylamide(PAM),and durability-related properties of the mortars were investigated comprehensively.Mortars with 5%PAM exhibited the best performance in terms of flexural strength among all the mixtures.The mechanical strength of cement pastes modified by in situ polymerization of AM monomers was significantly superior to those modified by PAM.The chemical interactions between the polymer molecules and cement hydrates together with the formation of polymer films glued the cement hydrates and polymers and resulted in an interpenetrating network structure,which strengthened the flexural strength.Reductions in porosity and calcium hydroxide content and improvement in capillary water absorption were achieved with the addition of PAM.Finally,the chloride resistance was significantly enhanced with the incorporation of PAM.展开更多
基金the EPSRC SWIMS(EP/V039717/1)Royal Society(RGS\R1\221009 and IEC\NSFC\211201)+4 种基金Leverhulme Trust(RPG-6062022-263)Sêr Cymru programme-Enhancing Competitiveness Equipment Awards 2022-23(MA/VG/2715/22-PN66)the financial support from National Natural Science Foundation of China(NSFC)Grant No.62105214the financial support from National Natural Science Foundation of China(NSFC)No.61974006Shenzhen Science and Technology Innovation Committee(KJZD20230923113759002 and GJHZ20240218113959009).
文摘The surging demand and adoption of infrared photodetectors(IRPDs)in sectors of imaging,mobile,healthcare,automobiles,and optical communication are hindered by the prohibitive costs of traditional IRPD materials such as InGaAs and HgCdTe.Quantum dots(QDs),especially lead chalcogenide(PbS)QDs,represent the next-generation lowbandgap semiconductors for near-infrared(NIR)detection due to their high optical absorption coefficient,tunable bandgap,low fabrication costs,and device compatibility.Innovative techniques such as ligand exchange processes have been proposed to boost the performance of PbS QDs photodetectors,mostly using short ligands like 1,2-ethanedithiol(EDT)and tetrabutylammonium iodide(TBAI).Our study explores the use of long-chain dithiol ligands to enhance the responsivity of PbS QDs/InGaZnO phototransistors.Long-chain dithiol ligands are found to suppress horizontal electron transport/leakage and electron trapping,which is beneficial for responsivity.Utilizing a novel ligand-exchange technique with 1,10-decanedithiol(DDT),we develop high-performance hybrid phototransistors with detectivity exceeding 10^(14) Jones.Based on these phototransistors,we demonstrate image communication through a NIR optical communication system.The long-ligand PbS QDs/InGaZnO hybrid phototransistor demonstrates significant potential for NIR low-dose imaging and optical communication,particularly in scenarios requiring the detection of weak light signals at low frequencies.
基金This work was funded by the Science and Technology Development Fund,Macao SAR(No.0083/2018/A2)Multi-Year Research Grant(No.MYRG2018-00164-IAPME)Research&Development Grant for Chair Professor(No.CPG2020-00002-IAPME)from the University of Macao.
文摘ABSTRACT The low flexural strength and high brittleness of cementitious materials impair their service life in building structures.In this study,we developed a new polymer-modified mortar by in situ polymerization of acrylamide(AM)monomers during the cement setting,which enhanced the flexural and durable performances of mortars.The mechanical properties,micro-and-pore structures,hydrated products,interactions between cement hydrates and polyacrylamide(PAM),and durability-related properties of the mortars were investigated comprehensively.Mortars with 5%PAM exhibited the best performance in terms of flexural strength among all the mixtures.The mechanical strength of cement pastes modified by in situ polymerization of AM monomers was significantly superior to those modified by PAM.The chemical interactions between the polymer molecules and cement hydrates together with the formation of polymer films glued the cement hydrates and polymers and resulted in an interpenetrating network structure,which strengthened the flexural strength.Reductions in porosity and calcium hydroxide content and improvement in capillary water absorption were achieved with the addition of PAM.Finally,the chloride resistance was significantly enhanced with the incorporation of PAM.
