Perovskites have attracted widespread attention for laser applications due to their excellent optoelectronic properties.However,perovskite lasers typically exhibit a wavelength shift as pump density increases.Here,we ...Perovskites have attracted widespread attention for laser applications due to their excellent optoelectronic properties.However,perovskite lasers typically exhibit a wavelength shift as pump density increases.Here,we report a pump-induced wavelength shift-free laser achieved using a perovskite nanoplatelet with mixed orthorhombic and tetragonal phase.At 293 K,the tetragonal-phase perovskite nanoplatelet laser exhibits a blue shift of~0.4 nmµJ^(-1)cm^(2)with increasing pump density.In contrast,at 80 K,the orthorhombic-phase perovskite nanoplatelet laser exhibits a red shift of~1 nmµJ^(-1)cm^(2).By stabilizing the perovskite nanoplatelet in a mixed orthorhombic-tetragonal phase at 163 K,the pump induced wavelength shifts are completely suppressed,resulting in a wavelength-stable laser.Additionally,the lasing threshold decreases from 18.4µJ cm^(−2)at room temperature to 4.5µJ cm^(−2)at 163 K.This study presents a promising strategy for achieving pump-insensitive wavelength stability in micro/nano lasers.展开更多
Solution-processable,single-crystalline perovskite nanowires are ideal candidates for developing low-cost photodetectors,but their detectivities are limited due to a high level of unintentional defects.Through the sur...Solution-processable,single-crystalline perovskite nanowires are ideal candidates for developing low-cost photodetectors,but their detectivities are limited due to a high level of unintentional defects.Through the surfaceinitiated solution-growth method,we fabricated high-quality,single-crystalline,defects-suppressed MAPbI_(3) nanowires,which possess atomically smooth side surfaces with a surface roughness of 0.27 nm,corresponding to a carrier lifetime of 112.9 ns.By forming ohmic MAPbI_(3)∕Au contacts through the dry contact method,highperformance metal–semiconductor–metal photodetectors have been demonstrated with a record large linear dynamic range of 157 dB along with a record high detectivity of 1.2×10^(14) Jones at an illumination power density of 5.5 nW∕cm^(2).Such superior photodetector performance metrics are attributed to,first,the defects-suppressed property of the as-grown MAPbI_(3) nanowires,which leads to a quite low noise current in the dark,and second,the ohmic contact between MAPbI_(3) and Au interfaces,which gives rise to an improved responsivity compared with the Schottky contact counterpart.The realized high-performance MAPbI_(3) nanowire photodetector advances the development of low-cost photodetectors and has potential applications in weak-signal photodetection.展开更多
MAPbI_(3)perovskite has attracted widespread interests for developing low-cost near infrared semiconductor gain media.However,it faces the instability issue under operation conditions,which remains a critical challeng...MAPbI_(3)perovskite has attracted widespread interests for developing low-cost near infrared semiconductor gain media.However,it faces the instability issue under operation conditions,which remains a critical challenge.It is found that the instability of the MAPbI_(3)nanoplatelet laser comes from the thermal-induced degradation progressing from the surface defects towards neighboring regions.By using PbI_(2) passivation,the defect-initiated degradation is significantly suppressed and the nanoplatelet degrades in a layer-by-layer way,enabling the MAPbI_(3)laser to sustain for 4500 s(2.7×10^(7) pulses),which is nearly three times longer than that of the nanoplatelet laser without passivation.Meanwhile,the PbI_(2) passivated MAPbI_(3)nanoplatelet laser with the nanoplatelet cavity displays a maximum quality factor up to∼7800,the highest reported for all MAPbI_(3)nanoplatelet cavities.Furthermore,a high stability MAPbI_(3)nanoplatelet laser that can last for 8500 s(5.1×10^(7) pulses)is demonstrated based on a dual passivation strategy,by retarding the defect-initiated degradation and surface-initiated degradation simultaneously.This work provides in-depth insights for understanding the operating degradation of perovskite lasers,and the dual passivation strategy paves the way for developing high stability near infrared semiconductor laser media.展开更多
To the Editor:Mycobacterium marinum is a nontuberculous mycobacterium that can cause opportunistic infections in humans,ranging from a single cutaneous lesion to disseminated disease.[1]It was first isolated from a fi...To the Editor:Mycobacterium marinum is a nontuberculous mycobacterium that can cause opportunistic infections in humans,ranging from a single cutaneous lesion to disseminated disease.[1]It was first isolated from a fish in 1926 and identified as a cause of human infection in 1951.[1]The estimated annual incidence ranges from 0.04 to 0.27 per 100,000 persons in different countries.Outbreaks of M.marinum infections related to handling fish are not common,but have also been reported.展开更多
Quasi-two dimensional(2D)perovskites have emerged as a promising class of materials due to their remarkable photoluminescence efficiency,which stems from their exceptionally high exciton binding energies.The spatial c...Quasi-two dimensional(2D)perovskites have emerged as a promising class of materials due to their remarkable photoluminescence efficiency,which stems from their exceptionally high exciton binding energies.The spatial confinement of excitons within smaller grain sizes could enhance the formation of biexcitons leading to higher radiative recombination efficiency.However,the synthesis of high-quality quasi-2D perovskite thin films with controllable grain sizes remains a challenging task.In this study,we present a facile method for achieving quasi-2D perovskite thin films with controllable grain sizes ranging from 500 to 900 nm.This is accomplished by intermediate phase engineering during the film fabrication process.Our results demonstrate that quasi-2D perovskite films with smaller grain sizes exhibit more efficient bound exciton generation and a reduced stimulated emission threshold down to 15.89µJ cm^(−2).Furthermore,femtosecond transient absorption measurements reveal that the decay time of bound excitons is shorter in quasi-2D perovskites with smaller grain sizes compared to that of those with larger grains at the same pump density,which is 230.5 ps.This observation suggests a more efficient exciton recombination process in the smaller grain size regime.Our findings would offer a promising approach for the development of efficient bound exciton lasers.展开更多
The layered two-dimensional material tungsten diselenide(WSe_(2))has triggered tremendous interests in the field of optoelectronic devices due to its exceptional carrier transport property.Nevertheless,the limited abs...The layered two-dimensional material tungsten diselenide(WSe_(2))has triggered tremendous interests in the field of optoelectronic devices due to its exceptional carrier transport property.Nevertheless,the limited absorption of WSe_(2) in the near infrared(NIR)band poses a challenge for the application of WSe_(2) photodetectors in night vision,telecommunication,etc.Herein,the enhanced performance of the WSe_(2) photodetector is demonstrated through the incorporation of titanium nitride nanoparticles(TiN NPs),complemented by an atomically-thick Al_(2)O_(3) layer that aids in suppressing the dark current.It is demonstrated that TiN NPs can dramatically enhance the absorption of light in the proposed WSe_(2) photodetector in the NIR regime.This enhancement boosts photocurrent responses through the generation of plasmonic hot electrons,leading to external quantum efficiency(EQE)enhancement factors of 379.66%at 850 nm and 178.47%at 1550 nm.This work presents,for the first time,to our knowledge,that the WSe_(2) photodetector is capable of detecting broadband light spanning from ultraviolet to the telecommunication range,all achieved without the reliance on additional semiconductor materials.This achievement opens avenues for the advancement of cost-effective NIR photodetectors.展开更多
Lead-free perovskite Cs_(2)AgBiBr_(6)manifests great potential in developing high-performance,environmentally friendly,solution-processable photodetectors(PDs).However,due to the relatively large energy bandgap,the sp...Lead-free perovskite Cs_(2)AgBiBr_(6)manifests great potential in developing high-performance,environmentally friendly,solution-processable photodetectors(PDs).However,due to the relatively large energy bandgap,the spectrum responses of Cs_(2)AgBiBr_(6)PDs are limited to the ultraviolet and visible region with wavelengths shorter than 560 nm.In this work,a broadband Cs_(2)AgBiBr_(6)PD covering the ultraviolet,visible,and near infrared(NIR)range is demonstrated by incorporating titanium nitride(TiN)nanoparticles that are prepared with the assistance of self-assembled polystyrene sphere array.In addition,an atomically thick Al2O3layer is introduced at the interface between the Cs_(2)AgBiBr_(6)film and TiN nanoparticles to alleviate the dark current deterioration caused by nanoparticle incorporation.As a result,beyond the spectrum range where Cs_(2)AgBiBr_(6)absorbs light,the external quantum efficiency(EQE)of the TiN nanoparticle incorporated Cs_(2)AgBiBr_(6)PD is enhanced significantly compared with that of the control,displaying enhancement factors as high as 2000 over a broadband NIR wavelength range.The demonstrated enhancement in EQE arises from the photocurrent contribution of plasmonic hot holes injected from TiN nanoparticles into Cs_(2)AgBiBr_(6).This work promotes the development of broadband solution-processable perovskite PDs,providing a promising strategy for realizing photodetection in the NIR region.展开更多
基金supported by the National Natural Science Foundation of China(U21A20496,62174117)Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(20230011)+5 种基金Research Program Supported by Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2022SX-TD020)Central Government Guides Local Funds for Scientific and Technological Development(YDZJSX20231A010)State Key Laboratory Program of Quantum Optics and Quantum Optics Devices(KF202306)Zheng K acknowledges the research grants from the Denmark VILLUM FONDEND(VIL50350)Swedish Research Council(2021-05319)Swedish Foundation for International Cooperation in Research and Higher Education(STINT,CH2019-8248).
文摘Perovskites have attracted widespread attention for laser applications due to their excellent optoelectronic properties.However,perovskite lasers typically exhibit a wavelength shift as pump density increases.Here,we report a pump-induced wavelength shift-free laser achieved using a perovskite nanoplatelet with mixed orthorhombic and tetragonal phase.At 293 K,the tetragonal-phase perovskite nanoplatelet laser exhibits a blue shift of~0.4 nmµJ^(-1)cm^(2)with increasing pump density.In contrast,at 80 K,the orthorhombic-phase perovskite nanoplatelet laser exhibits a red shift of~1 nmµJ^(-1)cm^(2).By stabilizing the perovskite nanoplatelet in a mixed orthorhombic-tetragonal phase at 163 K,the pump induced wavelength shifts are completely suppressed,resulting in a wavelength-stable laser.Additionally,the lasing threshold decreases from 18.4µJ cm^(−2)at room temperature to 4.5µJ cm^(−2)at 163 K.This study presents a promising strategy for achieving pump-insensitive wavelength stability in micro/nano lasers.
基金National Natural Science Foundation of China(61922060,61775156,61905173,U1710115,U1810204)Natural Science Foundation of Shanxi Province(201801D221029)+2 种基金Henry Fok Education Foundation Young Teachers FundYoung Sanjin Scholars ProgramKey Research and Development(International Cooperation)Program of Shanxi Province(201803D421044)。
文摘Solution-processable,single-crystalline perovskite nanowires are ideal candidates for developing low-cost photodetectors,but their detectivities are limited due to a high level of unintentional defects.Through the surfaceinitiated solution-growth method,we fabricated high-quality,single-crystalline,defects-suppressed MAPbI_(3) nanowires,which possess atomically smooth side surfaces with a surface roughness of 0.27 nm,corresponding to a carrier lifetime of 112.9 ns.By forming ohmic MAPbI_(3)∕Au contacts through the dry contact method,highperformance metal–semiconductor–metal photodetectors have been demonstrated with a record large linear dynamic range of 157 dB along with a record high detectivity of 1.2×10^(14) Jones at an illumination power density of 5.5 nW∕cm^(2).Such superior photodetector performance metrics are attributed to,first,the defects-suppressed property of the as-grown MAPbI_(3) nanowires,which leads to a quite low noise current in the dark,and second,the ohmic contact between MAPbI_(3) and Au interfaces,which gives rise to an improved responsivity compared with the Schottky contact counterpart.The realized high-performance MAPbI_(3) nanowire photodetector advances the development of low-cost photodetectors and has potential applications in weak-signal photodetection.
基金Science and Technology Innovation Commission of Shenzhen(JCYJ20170811093453105,JCYJ20170818141519879)Shenzhen Nanshan District Pilotage Team Program(LHTD20170006)+5 种基金Natural Science Foundation of Guangdong Province(2018A030313401)Platform and Base Special Project of Shanxi Province(201805D131012-3)Henry Fok Education Foundation Young Teachers FundKey Research and Development(International Cooperation)Program of Shanxi Province(201803D421044)Transformation Cultivation Project of University Scientific and Technological Achievements of Shanxi Province(2020CG013)National Natural Science Foundation of China(61775156YC,61922060YC,61961136001ZH)。
文摘MAPbI_(3)perovskite has attracted widespread interests for developing low-cost near infrared semiconductor gain media.However,it faces the instability issue under operation conditions,which remains a critical challenge.It is found that the instability of the MAPbI_(3)nanoplatelet laser comes from the thermal-induced degradation progressing from the surface defects towards neighboring regions.By using PbI_(2) passivation,the defect-initiated degradation is significantly suppressed and the nanoplatelet degrades in a layer-by-layer way,enabling the MAPbI_(3)laser to sustain for 4500 s(2.7×10^(7) pulses),which is nearly three times longer than that of the nanoplatelet laser without passivation.Meanwhile,the PbI_(2) passivated MAPbI_(3)nanoplatelet laser with the nanoplatelet cavity displays a maximum quality factor up to∼7800,the highest reported for all MAPbI_(3)nanoplatelet cavities.Furthermore,a high stability MAPbI_(3)nanoplatelet laser that can last for 8500 s(5.1×10^(7) pulses)is demonstrated based on a dual passivation strategy,by retarding the defect-initiated degradation and surface-initiated degradation simultaneously.This work provides in-depth insights for understanding the operating degradation of perovskite lasers,and the dual passivation strategy paves the way for developing high stability near infrared semiconductor laser media.
基金Academic promotion program of Shandong First Medical University(Nos. 2019LJ002, 2019RC007, and 2020RC001)Innovation Project of Shandong Academy of Medical Sciences+2 种基金the Shandong Province Taishan Scholar Project(Nos. tsqn201812124 and tspd20150214)Youth Technology Innovation Support Project of Shandong Colleges and Universities(No. 2019KJL003)Natural Science Foundation of Shandong Province(No. ZR2018BC020)
文摘To the Editor:Mycobacterium marinum is a nontuberculous mycobacterium that can cause opportunistic infections in humans,ranging from a single cutaneous lesion to disseminated disease.[1]It was first isolated from a fish in 1926 and identified as a cause of human infection in 1951.[1]The estimated annual incidence ranges from 0.04 to 0.27 per 100,000 persons in different countries.Outbreaks of M.marinum infections related to handling fish are not common,but have also been reported.
基金supported by the National Natural Science Foundation of China(U21A20496 and 12104334)the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(20230011)+5 种基金the Research Program Supported by ShanxiZheda Institute of Advanced Materials and Chemical Engineering(2022SXTD020)the Central Government Guides Local Funds for Scientific and Technological Development(YDZJSX20231A010)the Natural Science Foundation of Shanxi Province(202203021222102)the State Key Laboratory Program of Quantum Optics and Quantum Optics Devices(KF202306)the support from a research grant(VIL50350)from VILLUM FONDEN,Denmark,the Swedish Research Council(2021-05319)the Swedish foundation of international cooperation in research and higher education(CH2019-8248)。
文摘Quasi-two dimensional(2D)perovskites have emerged as a promising class of materials due to their remarkable photoluminescence efficiency,which stems from their exceptionally high exciton binding energies.The spatial confinement of excitons within smaller grain sizes could enhance the formation of biexcitons leading to higher radiative recombination efficiency.However,the synthesis of high-quality quasi-2D perovskite thin films with controllable grain sizes remains a challenging task.In this study,we present a facile method for achieving quasi-2D perovskite thin films with controllable grain sizes ranging from 500 to 900 nm.This is accomplished by intermediate phase engineering during the film fabrication process.Our results demonstrate that quasi-2D perovskite films with smaller grain sizes exhibit more efficient bound exciton generation and a reduced stimulated emission threshold down to 15.89µJ cm^(−2).Furthermore,femtosecond transient absorption measurements reveal that the decay time of bound excitons is shorter in quasi-2D perovskites with smaller grain sizes compared to that of those with larger grains at the same pump density,which is 230.5 ps.This observation suggests a more efficient exciton recombination process in the smaller grain size regime.Our findings would offer a promising approach for the development of efficient bound exciton lasers.
基金National Natural Science Foundation of China(62205235,U21A20496,62204157,62174117)Introduction of Talents Special Project of Lvliang City(Rc2020206,Rc2020207)+4 种基金Research Project Supported by Shanxi Scholarship Council of China(2021-033)Research Program Supported by Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2021SX-FR008,2022SX-TD020)Central Government Guides Local Funds for Scientific and Technological Development(YDZJSX2021A012,YDZJSX20231A010)Natural Science Foundation of Shanxi Province(20210302123154)Key Research and Development Program of Shanxi Province(202102150101007)。
文摘The layered two-dimensional material tungsten diselenide(WSe_(2))has triggered tremendous interests in the field of optoelectronic devices due to its exceptional carrier transport property.Nevertheless,the limited absorption of WSe_(2) in the near infrared(NIR)band poses a challenge for the application of WSe_(2) photodetectors in night vision,telecommunication,etc.Herein,the enhanced performance of the WSe_(2) photodetector is demonstrated through the incorporation of titanium nitride nanoparticles(TiN NPs),complemented by an atomically-thick Al_(2)O_(3) layer that aids in suppressing the dark current.It is demonstrated that TiN NPs can dramatically enhance the absorption of light in the proposed WSe_(2) photodetector in the NIR regime.This enhancement boosts photocurrent responses through the generation of plasmonic hot electrons,leading to external quantum efficiency(EQE)enhancement factors of 379.66%at 850 nm and 178.47%at 1550 nm.This work presents,for the first time,to our knowledge,that the WSe_(2) photodetector is capable of detecting broadband light spanning from ultraviolet to the telecommunication range,all achieved without the reliance on additional semiconductor materials.This achievement opens avenues for the advancement of cost-effective NIR photodetectors.
基金National Natural Science Foundation of China(U21A20496,62174117,12104334,62205235)Key Research and Development Program of Shanxi Province(202102150101007)+5 种基金Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(20230011)Research Program Supported by Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2021SX-FR008,2022SX-TD020)Central Government Guides Local Funds for Scientific and TechnologicalDevelopment(YDZJSX20231A010,YDZJSX2021A012)Natural Science Foundation of Shanxi Province(20210302123154,20210302123169)Research Project Supported by Shanxi Scholarship Council of China(2021-033)State Key Laboratory Program of Quantum Optics and Quantum Optics Devices(KF202306)。
文摘Lead-free perovskite Cs_(2)AgBiBr_(6)manifests great potential in developing high-performance,environmentally friendly,solution-processable photodetectors(PDs).However,due to the relatively large energy bandgap,the spectrum responses of Cs_(2)AgBiBr_(6)PDs are limited to the ultraviolet and visible region with wavelengths shorter than 560 nm.In this work,a broadband Cs_(2)AgBiBr_(6)PD covering the ultraviolet,visible,and near infrared(NIR)range is demonstrated by incorporating titanium nitride(TiN)nanoparticles that are prepared with the assistance of self-assembled polystyrene sphere array.In addition,an atomically thick Al2O3layer is introduced at the interface between the Cs_(2)AgBiBr_(6)film and TiN nanoparticles to alleviate the dark current deterioration caused by nanoparticle incorporation.As a result,beyond the spectrum range where Cs_(2)AgBiBr_(6)absorbs light,the external quantum efficiency(EQE)of the TiN nanoparticle incorporated Cs_(2)AgBiBr_(6)PD is enhanced significantly compared with that of the control,displaying enhancement factors as high as 2000 over a broadband NIR wavelength range.The demonstrated enhancement in EQE arises from the photocurrent contribution of plasmonic hot holes injected from TiN nanoparticles into Cs_(2)AgBiBr_(6).This work promotes the development of broadband solution-processable perovskite PDs,providing a promising strategy for realizing photodetection in the NIR region.
