Oxygen vacancies have been widely concerned with the facilitation effects of CO_(2)activation for CO_(2)methanation.However,little attention has been paid to the generation of active intermediate species induced by en...Oxygen vacancies have been widely concerned with the facilitation effects of CO_(2)activation for CO_(2)methanation.However,little attention has been paid to the generation of active intermediate species induced by enriched oxygen vacancies.Herein,we discovered that CeNiO_(3−δ)catalyst enriched oxygen vacancies can efficiently activate CO_(2)and realize high activity for photothermal CO_(2)methanation.In situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)proved that oxygen vacancies are beneficial to the formation of reactive intermediate species of polydentate carbonate over CeNiO_(3−δ),which is crucial for efficient CO_(2)methanation.These results revealed mechanistic insights into how effective CO_(2)activation induced by oxygen vacancies can be manipulated by adjusting the adsorption intermediate species.展开更多
Recently,water extraction based on the indices method has been documented in many studies using various remote sensing data sources.Among them,Landsat satellites data have certain advantages in spatial resolution and ...Recently,water extraction based on the indices method has been documented in many studies using various remote sensing data sources.Among them,Landsat satellites data have certain advantages in spatial resolution and cost.After the successful launch of Landsat 8,the Operational Land Imager(OLI)data from the satellite are getting more and more attention because of its new improvements.In this study,we used the OLI imagery data source to study the water extraction performance based on the Normalized Difference Vegetation Index,Normalized Difference Water Index,Modified Normalized Water Index(MNDWI),and Automated Water Extraction Index(AWEI)and compared the results with the Thematic Mapper(TM)imagery data.Two test sites in Tianjin City of north China were selected as the study area to verify the applicability of OLI data and demonstrate its advantages over TM data.We found that the results of surface water extraction based on OLI data are slightly better than that based on TM in the two test sites,especially in the city site.The AWEI and MNDWI indices performs better than the other two indices,and the thresholds of water indices show more stability when using the OLI data.So,it is suitable to combine OLI imagery with other Landsat sensor data to study water changes for long periods of time.展开更多
Vacuum-deposited perovskite light-emitting diodes(PeLEDs)have demonstrated significant potential for high-colorgamut active-matrix displays.Despite the rapid advance of green PeLEDs,red ones remain a considerable chal...Vacuum-deposited perovskite light-emitting diodes(PeLEDs)have demonstrated significant potential for high-colorgamut active-matrix displays.Despite the rapid advance of green PeLEDs,red ones remain a considerable challenge because of the inferior photophysical properties of vacuum-deposited red-light-emitting materials.Here,a rationally designed fluorine-modified phosphine oxide additive was introduced to in-situ passivate vacuum-deposited perovskites.The highly polar 2-F-TPPO incorporated perovskite films demonstrated enhanced photoluminescence quantum yield(PLQY),suppressed defects,and improved crystallinity.When implemented as active layers in PeLEDs,an external quantum efficiency(EQE)of 12.6%with an emission wavelength of 640 nm is achieved,which was 6 times higher compared to the previously reported most efficient vacuum-deposited red PeLEDs(EQE below 2%).Our findings lay the foundations for the further exploration of high-performance vacuum-deposited PeLEDs toward fullcolor perovskite displays.展开更多
Perovskite-based optoelectronic devices,espe-cially perovskite light-emitting diodes(PeLEDs)and perovskite solar cells,have recently attracted considerable attention.The National Renewable Energy Laboratory(NREL)chart...Perovskite-based optoelectronic devices,espe-cially perovskite light-emitting diodes(PeLEDs)and perovskite solar cells,have recently attracted considerable attention.The National Renewable Energy Laboratory(NREL)chart inspires us to develop a counterpart for PeLEDs.In this study,we collect the record performance of PeLEDs including several new entries to address their latest external quantum efficiency(EQE),highest lumi-nance,and stability status.We hope that these performance tables and future updated versions will show the frontiers of PeLEDs,assist researchers in capturing the overview of this field,identify the remaining challenges,and predict the promising research directions.展开更多
Yellow light-emitting diodes(LEDs) are widely utilized in high-quality lighting, light communication,indicator lamps, etc. Owing to their outstanding material properties and device performance, the metal halide perovs...Yellow light-emitting diodes(LEDs) are widely utilized in high-quality lighting, light communication,indicator lamps, etc. Owing to their outstanding material properties and device performance, the metal halide perovskites have demonstrated a significant potential for LED applications. However, the performance of the yellow perovskite LEDs(PeLEDs) is inferior to that of their green and red counterparts, with the maximum external quantum efficiency(EQE) limited to ~3.1%. Further, a majority of the yellow PeLEDs are fabricated using the spin-coating methods. The current study reports the development of the yellow CsPbBr_(2)I PeLEDs based on an all-vacuum deposition approach, which has been widely employed in the commercial organic LEDs(OLEDs). By controlling the co-evaporation rate of CsI and PbBr;, the growth kinetics of the perovskite layer are regulated to achieve a small grain size of~31.8 nm. Consequently, an improved radiative recombination rate(8.04 × 10^(-9)cm^(3)/s) is obtained owing to the spatial confinement effect. The PeLEDs based on the optimal perovskite film demonstrate the yellow electroluminescence(574 nm) with a maximum EQE of ~3.7% and luminance of~16,200 cd/m^(2), thus, representing one of the most efficient and bright yellow PeLEDs. Overall, this study provides a useful guideline for realizing the efficient PeLEDs based on the thermal evaporation strategy and highlights the potential of PeLED as an efficient and bright yellow light source.展开更多
基金Financial support from the National Natural Science Foundation of China(Nos.22025202,51572191,and 21633004)the Jiangsu Funding Program for Excellent Postdoctoral Talent is gratefully acknowledged.
文摘Oxygen vacancies have been widely concerned with the facilitation effects of CO_(2)activation for CO_(2)methanation.However,little attention has been paid to the generation of active intermediate species induced by enriched oxygen vacancies.Herein,we discovered that CeNiO_(3−δ)catalyst enriched oxygen vacancies can efficiently activate CO_(2)and realize high activity for photothermal CO_(2)methanation.In situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)proved that oxygen vacancies are beneficial to the formation of reactive intermediate species of polydentate carbonate over CeNiO_(3−δ),which is crucial for efficient CO_(2)methanation.These results revealed mechanistic insights into how effective CO_(2)activation induced by oxygen vacancies can be manipulated by adjusting the adsorption intermediate species.
基金The authors would like to thank the support by the Key Research Program of the Chinese Academy of Science[grant number KZZD–EW–14]the Visiting Scholar Foundation of Chinese Academy of Science.The authors would like to thank USGS for processing and providing Landsat data and the reviewers for their constructive comments and suggestions.The authors especially thank Prof Xiangming Xiao in the Earth Observation and Modeling Facility,University of Oklahoma,for his useful suggestions to this paper.
文摘Recently,water extraction based on the indices method has been documented in many studies using various remote sensing data sources.Among them,Landsat satellites data have certain advantages in spatial resolution and cost.After the successful launch of Landsat 8,the Operational Land Imager(OLI)data from the satellite are getting more and more attention because of its new improvements.In this study,we used the OLI imagery data source to study the water extraction performance based on the Normalized Difference Vegetation Index,Normalized Difference Water Index,Modified Normalized Water Index(MNDWI),and Automated Water Extraction Index(AWEI)and compared the results with the Thematic Mapper(TM)imagery data.Two test sites in Tianjin City of north China were selected as the study area to verify the applicability of OLI data and demonstrate its advantages over TM data.We found that the results of surface water extraction based on OLI data are slightly better than that based on TM in the two test sites,especially in the city site.The AWEI and MNDWI indices performs better than the other two indices,and the thresholds of water indices show more stability when using the OLI data.So,it is suitable to combine OLI imagery with other Landsat sensor data to study water changes for long periods of time.
基金supported by the National Natural Science Foundation of China(62322505,62425502,62374069,62375060,62375276,U23A6002,and 62104077)Shanghai Pilot Program for Basic Research(22JC1403200)+2 种基金“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2024C01192)the Natural Science Foundation of Hubei Province(2024AFB423 and 2023BAB102)the National Key Research and Development Program of China(2021YFB3501800,2023YFB3608903,2024YFA1209503).
文摘Vacuum-deposited perovskite light-emitting diodes(PeLEDs)have demonstrated significant potential for high-colorgamut active-matrix displays.Despite the rapid advance of green PeLEDs,red ones remain a considerable challenge because of the inferior photophysical properties of vacuum-deposited red-light-emitting materials.Here,a rationally designed fluorine-modified phosphine oxide additive was introduced to in-situ passivate vacuum-deposited perovskites.The highly polar 2-F-TPPO incorporated perovskite films demonstrated enhanced photoluminescence quantum yield(PLQY),suppressed defects,and improved crystallinity.When implemented as active layers in PeLEDs,an external quantum efficiency(EQE)of 12.6%with an emission wavelength of 640 nm is achieved,which was 6 times higher compared to the previously reported most efficient vacuum-deposited red PeLEDs(EQE below 2%).Our findings lay the foundations for the further exploration of high-performance vacuum-deposited PeLEDs toward fullcolor perovskite displays.
基金supported by the National Key R&D Program of China(No.2016YFB070700702)the National Natural Science Foundation of China(Grant No.51761145048)+1 种基金the Fundamental Research Funds for the Central Universities(HUST:2019421JYCXJJ004)the Innovation Funds of Wuhan National Laboratory for Optoelectronics(WNLO).
文摘Perovskite-based optoelectronic devices,espe-cially perovskite light-emitting diodes(PeLEDs)and perovskite solar cells,have recently attracted considerable attention.The National Renewable Energy Laboratory(NREL)chart inspires us to develop a counterpart for PeLEDs.In this study,we collect the record performance of PeLEDs including several new entries to address their latest external quantum efficiency(EQE),highest lumi-nance,and stability status.We hope that these performance tables and future updated versions will show the frontiers of PeLEDs,assist researchers in capturing the overview of this field,identify the remaining challenges,and predict the promising research directions.
基金supported by the National Natural Science Foundation of China(62050039 61725401 5171101030 51761145048 62004075 62005089 and 51902113)the National Key R&D Program of China(2016YFA0204000 and 2016YFB0201204)+2 种基金the Fundamental Research Funds for the Central Universities(HUST: 2019421JYCXJJ004)the Fund for Innovative Research Groups of the Natural Science Foundation of Hubei Province(2020CFA034)the Graduates’ Innovation Fund of Huazhong University of Science and Technology(HUST)(2021yjscxcy036)。
文摘Yellow light-emitting diodes(LEDs) are widely utilized in high-quality lighting, light communication,indicator lamps, etc. Owing to their outstanding material properties and device performance, the metal halide perovskites have demonstrated a significant potential for LED applications. However, the performance of the yellow perovskite LEDs(PeLEDs) is inferior to that of their green and red counterparts, with the maximum external quantum efficiency(EQE) limited to ~3.1%. Further, a majority of the yellow PeLEDs are fabricated using the spin-coating methods. The current study reports the development of the yellow CsPbBr_(2)I PeLEDs based on an all-vacuum deposition approach, which has been widely employed in the commercial organic LEDs(OLEDs). By controlling the co-evaporation rate of CsI and PbBr;, the growth kinetics of the perovskite layer are regulated to achieve a small grain size of~31.8 nm. Consequently, an improved radiative recombination rate(8.04 × 10^(-9)cm^(3)/s) is obtained owing to the spatial confinement effect. The PeLEDs based on the optimal perovskite film demonstrate the yellow electroluminescence(574 nm) with a maximum EQE of ~3.7% and luminance of~16,200 cd/m^(2), thus, representing one of the most efficient and bright yellow PeLEDs. Overall, this study provides a useful guideline for realizing the efficient PeLEDs based on the thermal evaporation strategy and highlights the potential of PeLED as an efficient and bright yellow light source.
