This review provides a comprehensive account of energy efficient lighting devices, their working principles and the advancement of these materials as an underpinning to the development of technology. Particular attent...This review provides a comprehensive account of energy efficient lighting devices, their working principles and the advancement of these materials as an underpinning to the development of technology. Particular attention has been given to solid state lighting devices and their applications since they have attracted the most interest and are the most promising. Solid state lighting devices including white light emitting diodes （LEDs）, organic LEDs （OLEDs）, quantum-dot LEDs （QLEDs） and carbon-dot LEDs （CLEDs） are promising energy efficient lighting sources for displays and general lighting. However there is no universal solution that will give better performance and efficiency for all types of applications. LEDs are replacing traditional lamp,; for both general lighting and display applications, whereas OLEDs are finding their own special application,; in various areas. QLEDs and CLEDs have advantages such as high quantum yields, narrow emission spectra, tunable emission spectra and good stability over OLEDs, so applications for these devices are being extended to new types of lighting sources. There is a great dean of research on these materials and their processing technologies and the commercial viability of these technologies appears strong.展开更多
A three-terminal silicon-based light emitting device is proposed and fabricated in standard 0.35 μm complementary metal-oxide-semiconductor technology. This device is capable of versatile working modes： it can emit ...A three-terminal silicon-based light emitting device is proposed and fabricated in standard 0.35 μm complementary metal-oxide-semiconductor technology. This device is capable of versatile working modes： it can emit visible to near infra-red （NIR） light （the spectrum ranges from 500 nm to 1000 nm） in reverse bias avalanche breakdown mode with working voltage between 8.35 V-12 V and emit NIR light （the spectrum ranges from 900 nm to 1300 nm） in the forward injection mode with working voltage below 2 V. An apparent modulation effect on the light intensity from the polysilicon gate is observed in the forward injection mode. Furthermore, when the gate oxide is broken down, NIR light is emitted from the polysilicon/oxide/silicon structure. Optoelectronic characteristics of the device working in different modes are measured and compared. The mechanisms behind these different emissions are explored.展开更多
The performance of polymer light emitting devices(PLEDs)based on polyvinyl carbazole(PVK)is improved by introducing a nanoscale interfacial thin layer,made of poly(ethylene oxide)(PEO),between the calcium cathode and ...The performance of polymer light emitting devices(PLEDs)based on polyvinyl carbazole(PVK)is improved by introducing a nanoscale interfacial thin layer,made of poly(ethylene oxide)(PEO),between the calcium cathode and the PVK emissive layer.It is believed that the PEO layer plays a key role in enhancing the device performance.In comparison to the device with Ca/Al as the cathode,the performance of the PLED with PEO/Ca/Al cathode,including the driving voltage,luminance efficiency is significantly improved.These improvements are attributed to the introduction of a thin layer of PEO that can lower the interfacial barrier and facilitate electron injection.展开更多
We present a digital micromirror device（DMD） based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investig...We present a digital micromirror device（DMD） based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investigate focusing light through a scattering sample using the superpixel methods with different target complex fields.Then, single-point and multiple-point focusing experiments are performed using this superpixel-based complex modulation method. In our experiment, up to 71.5% relative enhancement is realized. The use of the DMDbased superpixel method for the control of the complex field of incident light opens an avenue to improve the enhancement of focusing light through scattering media.展开更多
Organic Light Emitting Devices (OLED) have attracted much attention recently, for their applications in futureFlat Panel Displays and lighting products. However, their fast degradation remained a major obstacle to the...Organic Light Emitting Devices (OLED) have attracted much attention recently, for their applications in futureFlat Panel Displays and lighting products. However, their fast degradation remained a major obstacle to theircommercialization. Here we present a brief summary of our studies on both extrinsic and intrinsic causes for the fastdegradation of OLEDs. In particular, we focus on the origin of the dark spots by 'rebuilding' cathodes, which confirms thatthe growth of dark spots occurs primarily due to cathode delamination. In the meantime, we recapture the findings from thesearch for suitable OLED packaging materials, in particular polymer composites, which provide both heat dissipation andmoisture resistance, in addition to electrical insulation.展开更多
A controllable etching process for indium zinc oxide （IZO） films was developed by using a weak etchant of oxalic acid with a slow etching ratio. With controllable etching time and temperature, a patterned IZO electr...A controllable etching process for indium zinc oxide （IZO） films was developed by using a weak etchant of oxalic acid with a slow etching ratio. With controllable etching time and temperature, a patterned IZO electrode with smoothed surface morphology and slope edge was achieved. For the practical application in organic light emitting devices （OLEDs）, a sup- pression of the leak current in the current-voltage characteristics of OLEDs was observed. It resulted in a 1.6 times longer half lifetime in the IZO-based OLEDs compared to that using an indium tin oxide （ITO） anode etched by a conventional strong etchant of aqua regia.展开更多
Using carbon felt, polytetrafluoroethylene latex and powder catalyst to assembly a light energy conversion device, the photocatalytic activity of catalyst 2.0%WO3-TiO2 （2%WO3 compounding TiO2） with oxygen vacancies ...Using carbon felt, polytetrafluoroethylene latex and powder catalyst to assembly a light energy conversion device, the photocatalytic activity of catalyst 2.0%WO3-TiO2 （2%WO3 compounding TiO2） with oxygen vacancies was studied through the water splitting for O2 evolution, using a high pressure mercury lamp as the light source and Fe^3＋ as the electron acceptor in two different devices： an ordinary photolysis device with catalyst powder suspending through a magnetic stirrer and a self-assembly light energy conversion device. The results show that after 12 h irradiation, the photocatalytic activity of 2.0%WO3-TiO2 with oxygen vacancies in the self-assembly light energy conversion device is higher than that of the ordinary photolysis device, and the amount of oxygen evolution is about 12 and 9 mmol/L respectively in these two devices. After 12 h, the rates of 02 evolution are slow in each device and the photocatalyst almost loses the photoactivity in the ordinary photolysis device. So, compared with the ordinary photocatalytic device, the rate of oxygen evolution and the life time of the catalyst are improved in the self-assembly light energy conversion device.展开更多
Some manufactures made UVC LED Strip as disinfection tool against SARS-CoV2. Therefore, three types of commercially UVC lights were used to evaluate their efficiency to warp bacteria and viruses. We tested three comme...Some manufactures made UVC LED Strip as disinfection tool against SARS-CoV2. Therefore, three types of commercially UVC lights were used to evaluate their efficiency to warp bacteria and viruses. We tested three commercially available UV lights devices. They were put at 4 to 5 cm to spiked sterile Petri dishes (samples) for 10, 20, 30, and 60 seconds and compared it to control (without UV light exposure). Also, the same three UV LED devices were used on Positive SARS-CoV2 swab samples (used for the Petri dishes). Serial dilutions of the cultured microbes were used for the experiment as follows: 1/10 (high concertation), 1/100, 1/1000, 1/10,000, 1/100,000 (low concertation). All three UV LED devices (DA, DB, DC) were found to have no effects on the pathogens (Bacteria or SARS-CoV2), even to the lowest Bacteria Concentration (1/100,000), when pathogens were exposed to UV radiation for 10, 20, 30, and 60 sec at distance a 4 to 5 cm. One of the manufacturers of these UVC lights (DB) claims that the device is very effective in killing Bacteria and Virus immediately at a 99.93% killing rate (in 20 sec.). This observation was not noticed. False claims may lead to severe spread of SARS-CoV2 as customers may think that the DB was disinfecting, after short exposure, while truly having no effect.展开更多
The toxicity of lead ions has become the severe challenge for the all-inorganic lead halide p erovskite materials,although some works have rep orted the lead-free perovskite nanocrystals(NCs),the photoluminescence qua...The toxicity of lead ions has become the severe challenge for the all-inorganic lead halide p erovskite materials,although some works have rep orted the lead-free perovskite nanocrystals(NCs),the photoluminescence quantum yield(PLQY)of these materials is still unsatisfactory.Meanwhile,because the halogen ions can be easily exchanged,the controllable multicolor emission in perovskite NCs is difficult to realize in current reports.In this work,we introduced lanthanide ions into lead-free Cs_(3)Sb_(2)Cl_(9) perovskite NCs.Benefitting from the energy transfer between Cs_(3)Sb_(2)Cl_(9) perovskite NC host and lanthanide ions,the multicolor emission was realized.Based on controlling the doping concentration of Tb^(3+)and Eu^(3+)ions,the white light emission under UV excitation would be turned easily in the Tb^(3+)/Eu^(3+)codoped NCs.In addition,efficient energy transfer from perovskite NCs to Tb^(3+)or Eu^(3+)ions is beneficial to improving the optical properties of lead-free perovskite NCs,resulting in maximum PLQYs of red,green and white light emission of 22.6%,19.7%and 28.5%,respectively.Finally,a white light emitting device(WLED)was fabricated with a power efficiency of 18.5 lm/W,which presents the Commission Internationale de l'Eclairage(CIE)of(0.33,0.35).展开更多
Organic light-emitting devices have attracted significant research interest due to their several advantages including flexibility,lightweight design,and low manufacturing cost.Upon the electric current applied,their e...Organic light-emitting devices have attracted significant research interest due to their several advantages including flexibility,lightweight design,and low manufacturing cost.Upon the electric current applied,their emitted light is typically unpolarized,whose electromagnetic fields oscillate randomly in all directions[1].In contrast,polarized light,resulting from electromagnetic field oscillating in a specific direction,is crucial for various applications such as optical communication.展开更多
Alternating current(AC)driven quantum dots(QDs)light-emitting diodes have attracted widespread attention due to their unique optoelectronic performance.An ACdriven device with an interdigital electrode structure is pr...Alternating current(AC)driven quantum dots(QDs)light-emitting diodes have attracted widespread attention due to their unique optoelectronic performance.An ACdriven device with an interdigital electrode structure is proposed.The devices exhibit AC electroluminescence(EL)with driving frequency and different frequency responses due to the introduction of P(VDF-TrFE-CFE).The optical and electrical characteristics of the device under various applied voltages and driving frequencies are studied.Unlike the conventional driving mode where carriers are continuously injected into the device,the carriers undergo periodic motion under an AC field.Therefore,there exists an optimal driving frequency that maximizes the EL intensity of the device.Based on the experimental results,the operational mechanism of the device is analyzed,and a carrier transport model is proposed to elucidate the underlying factors contributing to the presence of an optimal driving frequency.Moreover,a model for the device is proposed and its accuracy is verified.From a circuit perspective,the EL behavior of devices at various driving frequencies is analyzed,thereby further confirming the accuracy of the proposed device working mechanism.We believe the work can provide guidance for obtaining advanced QD-based lightemitting technology.展开更多
ZnO nanoparticles are widely used for the electron transport layers(ETLs)of quantum dots light emitting devices(QLEDs).In this work we show that incorporating fluorine(F)into the ZnO ETL results in significant enhance...ZnO nanoparticles are widely used for the electron transport layers(ETLs)of quantum dots light emitting devices(QLEDs).In this work we show that incorporating fluorine(F)into the ZnO ETL results in significant enhancement in device electroluminescence stability,leading to LT50 at 100 cd m^(−2) of 2,370,000 h in red QLED,47X longer than the control devices.X-ray photo-electron spectroscopy,time-of-flight secondary ion mass spectroscopy,photoluminescence and electrical measurements show that the F passivates oxygen vacancies and reduces electron traps in ZnO.Transient photoluminescence versus bias measurements and capacitance-voltage-luminance measurements reveal that the CF4 plasma-treated ETLs lead to increased electron concentration in the QD and the QD/hole transport layer interface,subsequently decreasing hole accumulation,and hence the higher stability.The findings provide new insights into the critical roles that optimizing charge distribution across the layers play in influencing stability and present a novel and simple approach for extending QLED lifetimes.展开更多
A series of Zn-Cu-In-S nanocrystals （ZCIS NCs） are prepared and the optical properties of the ZCIS NCs are tuned by adjusting the reaction time. It is interesting to observe that the temperature-dependent photolumin...A series of Zn-Cu-In-S nanocrystals （ZCIS NCs） are prepared and the optical properties of the ZCIS NCs are tuned by adjusting the reaction time. It is interesting to observe that the temperature-dependent photoluminescence （PL） spectra of the ZCIS NCs show a redshift with decreasing intensity at low temperature （50-280 K） and a blueshift at high temperature （318--403 K）. The blueshift can be explained by the thermally active phonon-assisted tunneling from the excited states of the low-energy emission band to the excited states of the high-energy emission band.展开更多
The Ce （x nm）/Au （15 nm） stacked layers were used as semitransparent cathodes in the top-emission organic light emitting devices （TOLEDs） fabricated on a p-type silicon anodes and substrate,where x varies from 4...The Ce （x nm）/Au （15 nm） stacked layers were used as semitransparent cathodes in the top-emission organic light emitting devices （TOLEDs） fabricated on a p-type silicon anodes and substrate,where x varies from 4 to 16.The consequence of the Ce layer thickness on transmittance and the device performance were studied when the organic layers NPB （60 nm）/ALQ （60 nm） were kept unchanged,where NPB was N,N＇-bis-（1-naphthl）-diphenyl-1,1＇-biphenyl-4,4＇-diamine,and AlQ is tris-（8-hydroxyquinoline） aluminum.The cathode of Ce （11 nm）/Au （15 nm） has a transparency of 46%,and the TOLED with it achieves the highest luminescence efficiencies：a current efficiency of 0.91 cd/A at 13.7 V and a peak power efficiency of 0.28 lm/W at 9 V.The turn-on voltage is 3.0 V.The Ce/Au cathode is both chemically and electrically stable.展开更多
ith the aid of a fibre optical device, the profile of plasma parameters, such as plasma length and noise power spectrum, in a normally enclosed TM 010 cavity was probed. Experimental results show that the physical len...ith the aid of a fibre optical device, the profile of plasma parameters, such as plasma length and noise power spectrum, in a normally enclosed TM 010 cavity was probed. Experimental results show that the physical length of a plasma is linearly related to the microwave power applied and that the profile of noise power spectra varies significantly along the length of a plasma.展开更多
Objectives: Peripheral neuropathy (PN) is a significant contributor to disability in the elderly. It is also one of the most prevalent complications of type 2 diabetes, prediabetes and metabolic syndrome. PN is common...Objectives: Peripheral neuropathy (PN) is a significant contributor to disability in the elderly. It is also one of the most prevalent complications of type 2 diabetes, prediabetes and metabolic syndrome. PN is commonly associated with pain, numbness, tingling, burning, and cramping in the feet and legs. Current treatment options are limited to controlling pain, seizures and use of antidepressant medications. These treatments have undesirable side effects and don’t stop PN progression. Here we utilized a combination of individual-specific modalities to improve local circulation and relieve PN symptoms. Methods: We conducted an open-label, multicenter pilot trial with 34 subjects (19 males and 15 females ranging from 40 - 85 years of age). All of the participants were diagnosed with peripheral neuropathy and had bilateral symptoms in their feet, and many reported the same symptoms (pain, numbness, tingling, burning, and cramping) in their lower legs. The duration of symptoms ranged from four months to over six years. On Day 0, subjects were given a 90-day supply of the oral supplement with dosing instructions and a LED light therapy device. They also received three platelet-rich plasma (PRP) injections in their lower extremities. Subjects also received an extracorporeal shockwave therapy (ESWT) treatment for each foot and subsequently twice per week for the first six weeks, then once weekly for the duration of the study. Subjects filled out the Brief Pain Index (BPI) at weekly intervals. On Day 90, subjects completed the Patient Global Impression of Change (PGIC) survey. Results: There were significant responses to pain, as evidenced by BPI scores at weeks 8, 9, 10 and 11 (p = 0.02, 0.01, 0.02, and 0.003, respectively). Analysis of the final day PGIC survey showed a favorable outcome for 73% of participants (p = 0.003), with the majority reporting Very Much Improved. Conclusions: By utilizing a multi-modality treatment protocol that includes PRP, LED light therapy, ESWT and an oral dietary supplement, we observed significant reductions in BPI scores. Quality of life and their overall impression of change (PGIC) were significantly improved, and there were no significant side effects.展开更多
Ordinary metal salts have become a promising afterglow material because of the characteristics of wide sources,low cost,and easy availability.However,their extremely weak afterglow efficiency makes them rarely used in...Ordinary metal salts have become a promising afterglow material because of the characteristics of wide sources,low cost,and easy availability.However,their extremely weak afterglow efficiency makes them rarely used in practical applications.In this study,we proposed a ligand engineering strategy to greatly enhance the afterglow efficiency of metal salts.Al_(2)(SO_(4))_(3),as a typical metal salt,has only a photoluminescence quantum yield(PL QY)as low as 0.1%and an unmeasurable phosphorescent QY.After doping with dual organic ligands,the PL QY of Al_(2)(SO_(4))_(3)has increased by nearly 200 times,reaching 19.90%.Meanwhile,the afterglow intensity of Al_(2)(SO_(4))_(3)has increased by approximately 20 times,accompanied by a great increase in phosphorescent lifetime from 416.15 to 2870.08 ms(a about 7-time increase).The enhancement mechanism of afterglow efficiency is ascribed to the fact that the excited electrons from the dual ligands can be directly captured by oxygen defects(trap),then transferred to the emitters(Al^(3+)ions),and ultimately achieving efficient afterglow luminescence.This study utilizes ligand engineering strategy to improve the afterglow luminescence efficiency of metal salts,achieving their applications in deep ultraviolet(UV)-excited light emitting devices and visual ethylene glycol recognition.展开更多
A systematic study has been conducted on microcavity organic light emitting diodes(OLEDs)based on green,red and blue phosphorescent emitters to elucidate the microcavity effects for different color emitters.We found t...A systematic study has been conducted on microcavity organic light emitting diodes(OLEDs)based on green,red and blue phosphorescent emitters to elucidate the microcavity effects for different color emitters.We found that the luminance output is determined by the reflectivity of the semitransparent electrode and the photopic response of the green,red and blue emitters.While the luminance enhancements of blue and red phosphorescent microcavity devices are small,a current efficiency as high as 224 cd A21 is obtained in the green phosphorescent microcavity OLEDs.展开更多
The debate over how one of the most popular osteoarthritis treatments should be federally regulated could change,thanks to a Cornell University study and a new device that provides a better understanding of the scienc...The debate over how one of the most popular osteoarthritis treatments should be federally regulated could change,thanks to a Cornell University study and a new device that provides a better understanding of the science behind hyaluronic acid(HA)injections.展开更多
A mixture of polydimethylsiloxane (PDMS) doped with phosphor particles can be found across diverse industries having different applications. This mixture plays a particularly important role in the field of lighting, w...A mixture of polydimethylsiloxane (PDMS) doped with phosphor particles can be found across diverse industries having different applications. This mixture plays a particularly important role in the field of lighting, white light-emitting diodes (LED's), flexible display devices, anti-counterfeiting (AC) solutions, luminescence thermometers and many types of sensors. The field of mechanoluminescence and biomedical are booming and there is also potential for visible light communication (VLC). In this comprehensive review, the basic characteristics of PDMS and a list of selected phosphors suitable for creating a mixture of PDMS and phosphor are presented. The summary and a detailed overview of the implemented applications of this perspective mixture over the last decade is presented as well.展开更多
文摘This review provides a comprehensive account of energy efficient lighting devices, their working principles and the advancement of these materials as an underpinning to the development of technology. Particular attention has been given to solid state lighting devices and their applications since they have attracted the most interest and are the most promising. Solid state lighting devices including white light emitting diodes （LEDs）, organic LEDs （OLEDs）, quantum-dot LEDs （QLEDs） and carbon-dot LEDs （CLEDs） are promising energy efficient lighting sources for displays and general lighting. However there is no universal solution that will give better performance and efficiency for all types of applications. LEDs are replacing traditional lamp,; for both general lighting and display applications, whereas OLEDs are finding their own special application,; in various areas. QLEDs and CLEDs have advantages such as high quantum yields, narrow emission spectra, tunable emission spectra and good stability over OLEDs, so applications for these devices are being extended to new types of lighting sources. There is a great dean of research on these materials and their processing technologies and the commercial viability of these technologies appears strong.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.60536030,61036002,60776024,60877035 and 61036009)National High Technology Research and Development Program of China(Grant Nos.2007AA04Z329 and 2007AA04Z254)
文摘A three-terminal silicon-based light emitting device is proposed and fabricated in standard 0.35 μm complementary metal-oxide-semiconductor technology. This device is capable of versatile working modes： it can emit visible to near infra-red （NIR） light （the spectrum ranges from 500 nm to 1000 nm） in reverse bias avalanche breakdown mode with working voltage between 8.35 V-12 V and emit NIR light （the spectrum ranges from 900 nm to 1300 nm） in the forward injection mode with working voltage below 2 V. An apparent modulation effect on the light intensity from the polysilicon gate is observed in the forward injection mode. Furthermore, when the gate oxide is broken down, NIR light is emitted from the polysilicon/oxide/silicon structure. Optoelectronic characteristics of the device working in different modes are measured and compared. The mechanisms behind these different emissions are explored.
基金the Office of R&D,National Cheng Kung University,Taiwan
文摘The performance of polymer light emitting devices(PLEDs)based on polyvinyl carbazole(PVK)is improved by introducing a nanoscale interfacial thin layer,made of poly(ethylene oxide)(PEO),between the calcium cathode and the PVK emissive layer.It is believed that the PEO layer plays a key role in enhancing the device performance.In comparison to the device with Ca/Al as the cathode,the performance of the PLED with PEO/Ca/Al cathode,including the driving voltage,luminance efficiency is significantly improved.These improvements are attributed to the introduction of a thin layer of PEO that can lower the interfacial barrier and facilitate electron injection.
基金Supported by the Natural Science Foundation of Beijing under Grant Nos 2162033 and 7182091the National Natural Science Foundation of China under Grant No 21627813
文摘We present a digital micromirror device（DMD） based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investigate focusing light through a scattering sample using the superpixel methods with different target complex fields.Then, single-point and multiple-point focusing experiments are performed using this superpixel-based complex modulation method. In our experiment, up to 71.5% relative enhancement is realized. The use of the DMDbased superpixel method for the control of the complex field of incident light opens an avenue to improve the enhancement of focusing light through scattering media.
文摘Organic Light Emitting Devices (OLED) have attracted much attention recently, for their applications in futureFlat Panel Displays and lighting products. However, their fast degradation remained a major obstacle to theircommercialization. Here we present a brief summary of our studies on both extrinsic and intrinsic causes for the fastdegradation of OLEDs. In particular, we focus on the origin of the dark spots by 'rebuilding' cathodes, which confirms thatthe growth of dark spots occurs primarily due to cathode delamination. In the meantime, we recapture the findings from thesearch for suitable OLED packaging materials, in particular polymer composites, which provide both heat dissipation andmoisture resistance, in addition to electrical insulation.
基金supported by the National Natural Science Foundation of China(Grant Nos.61307036 and 61307037)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),Chinathe University Science Research Project of Jiangsu Province,China(Grant No.12KJB510028)
文摘A controllable etching process for indium zinc oxide （IZO） films was developed by using a weak etchant of oxalic acid with a slow etching ratio. With controllable etching time and temperature, a patterned IZO electrode with smoothed surface morphology and slope edge was achieved. For the practical application in organic light emitting devices （OLEDs）, a sup- pression of the leak current in the current-voltage characteristics of OLEDs was observed. It resulted in a 1.6 times longer half lifetime in the IZO-based OLEDs compared to that using an indium tin oxide （ITO） anode etched by a conventional strong etchant of aqua regia.
基金Project(2010CL04) supported by the Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, ChinaProject(K-081025) supported by State Key Laboratory Breeding Base of Photocatalysis,Fuzhou University,China
文摘Using carbon felt, polytetrafluoroethylene latex and powder catalyst to assembly a light energy conversion device, the photocatalytic activity of catalyst 2.0%WO3-TiO2 （2%WO3 compounding TiO2） with oxygen vacancies was studied through the water splitting for O2 evolution, using a high pressure mercury lamp as the light source and Fe^3＋ as the electron acceptor in two different devices： an ordinary photolysis device with catalyst powder suspending through a magnetic stirrer and a self-assembly light energy conversion device. The results show that after 12 h irradiation, the photocatalytic activity of 2.0%WO3-TiO2 with oxygen vacancies in the self-assembly light energy conversion device is higher than that of the ordinary photolysis device, and the amount of oxygen evolution is about 12 and 9 mmol/L respectively in these two devices. After 12 h, the rates of 02 evolution are slow in each device and the photocatalyst almost loses the photoactivity in the ordinary photolysis device. So, compared with the ordinary photocatalytic device, the rate of oxygen evolution and the life time of the catalyst are improved in the self-assembly light energy conversion device.
文摘Some manufactures made UVC LED Strip as disinfection tool against SARS-CoV2. Therefore, three types of commercially UVC lights were used to evaluate their efficiency to warp bacteria and viruses. We tested three commercially available UV lights devices. They were put at 4 to 5 cm to spiked sterile Petri dishes (samples) for 10, 20, 30, and 60 seconds and compared it to control (without UV light exposure). Also, the same three UV LED devices were used on Positive SARS-CoV2 swab samples (used for the Petri dishes). Serial dilutions of the cultured microbes were used for the experiment as follows: 1/10 (high concertation), 1/100, 1/1000, 1/10,000, 1/100,000 (low concertation). All three UV LED devices (DA, DB, DC) were found to have no effects on the pathogens (Bacteria or SARS-CoV2), even to the lowest Bacteria Concentration (1/100,000), when pathogens were exposed to UV radiation for 10, 20, 30, and 60 sec at distance a 4 to 5 cm. One of the manufacturers of these UVC lights (DB) claims that the device is very effective in killing Bacteria and Virus immediately at a 99.93% killing rate (in 20 sec.). This observation was not noticed. False claims may lead to severe spread of SARS-CoV2 as customers may think that the DB was disinfecting, after short exposure, while truly having no effect.
基金Project supported by the National Natural Science Foundation of China(U21A2068,11974142,11874181,12204248)the Fundamental Research Funds for the Central UniversitiesJiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB399)。
文摘The toxicity of lead ions has become the severe challenge for the all-inorganic lead halide p erovskite materials,although some works have rep orted the lead-free perovskite nanocrystals(NCs),the photoluminescence quantum yield(PLQY)of these materials is still unsatisfactory.Meanwhile,because the halogen ions can be easily exchanged,the controllable multicolor emission in perovskite NCs is difficult to realize in current reports.In this work,we introduced lanthanide ions into lead-free Cs_(3)Sb_(2)Cl_(9) perovskite NCs.Benefitting from the energy transfer between Cs_(3)Sb_(2)Cl_(9) perovskite NC host and lanthanide ions,the multicolor emission was realized.Based on controlling the doping concentration of Tb^(3+)and Eu^(3+)ions,the white light emission under UV excitation would be turned easily in the Tb^(3+)/Eu^(3+)codoped NCs.In addition,efficient energy transfer from perovskite NCs to Tb^(3+)or Eu^(3+)ions is beneficial to improving the optical properties of lead-free perovskite NCs,resulting in maximum PLQYs of red,green and white light emission of 22.6%,19.7%and 28.5%,respectively.Finally,a white light emitting device(WLED)was fabricated with a power efficiency of 18.5 lm/W,which presents the Commission Internationale de l'Eclairage(CIE)of(0.33,0.35).
基金Received 14 February 2025accepted 20 February 2025。
文摘Organic light-emitting devices have attracted significant research interest due to their several advantages including flexibility,lightweight design,and low manufacturing cost.Upon the electric current applied,their emitted light is typically unpolarized,whose electromagnetic fields oscillate randomly in all directions[1].In contrast,polarized light,resulting from electromagnetic field oscillating in a specific direction,is crucial for various applications such as optical communication.
基金supported by the Natural Science Foundation of the Fujian Province,China(2024J010016)the National Key R&D Program of China(2021YFB3600400)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Project(2020ZZ113,2021ZZ130)。
文摘Alternating current(AC)driven quantum dots(QDs)light-emitting diodes have attracted widespread attention due to their unique optoelectronic performance.An ACdriven device with an interdigital electrode structure is proposed.The devices exhibit AC electroluminescence(EL)with driving frequency and different frequency responses due to the introduction of P(VDF-TrFE-CFE).The optical and electrical characteristics of the device under various applied voltages and driving frequencies are studied.Unlike the conventional driving mode where carriers are continuously injected into the device,the carriers undergo periodic motion under an AC field.Therefore,there exists an optimal driving frequency that maximizes the EL intensity of the device.Based on the experimental results,the operational mechanism of the device is analyzed,and a carrier transport model is proposed to elucidate the underlying factors contributing to the presence of an optimal driving frequency.Moreover,a model for the device is proposed and its accuracy is verified.From a circuit perspective,the EL behavior of devices at various driving frequencies is analyzed,thereby further confirming the accuracy of the proposed device working mechanism.We believe the work can provide guidance for obtaining advanced QD-based lightemitting technology.
基金Partial support to this work by the Natural Sciences & Engineering Research Council of Canada (NSERC) is gratefully acknowledged
文摘ZnO nanoparticles are widely used for the electron transport layers(ETLs)of quantum dots light emitting devices(QLEDs).In this work we show that incorporating fluorine(F)into the ZnO ETL results in significant enhancement in device electroluminescence stability,leading to LT50 at 100 cd m^(−2) of 2,370,000 h in red QLED,47X longer than the control devices.X-ray photo-electron spectroscopy,time-of-flight secondary ion mass spectroscopy,photoluminescence and electrical measurements show that the F passivates oxygen vacancies and reduces electron traps in ZnO.Transient photoluminescence versus bias measurements and capacitance-voltage-luminance measurements reveal that the CF4 plasma-treated ETLs lead to increased electron concentration in the QD and the QD/hole transport layer interface,subsequently decreasing hole accumulation,and hence the higher stability.The findings provide new insights into the critical roles that optimizing charge distribution across the layers play in influencing stability and present a novel and simple approach for extending QLED lifetimes.
基金supported by the National Natural Science Foundation of China(Grand Nos.60907021,60977035,and 60877029)the Natural Science Foundation of Tianjin,China(Grant No.11JCYBJC00300)
文摘A series of Zn-Cu-In-S nanocrystals （ZCIS NCs） are prepared and the optical properties of the ZCIS NCs are tuned by adjusting the reaction time. It is interesting to observe that the temperature-dependent photoluminescence （PL） spectra of the ZCIS NCs show a redshift with decreasing intensity at low temperature （50-280 K） and a blueshift at high temperature （318--403 K）. The blueshift can be explained by the thermally active phonon-assisted tunneling from the excited states of the low-energy emission band to the excited states of the high-energy emission band.
文摘The Ce （x nm）/Au （15 nm） stacked layers were used as semitransparent cathodes in the top-emission organic light emitting devices （TOLEDs） fabricated on a p-type silicon anodes and substrate,where x varies from 4 to 16.The consequence of the Ce layer thickness on transmittance and the device performance were studied when the organic layers NPB （60 nm）/ALQ （60 nm） were kept unchanged,where NPB was N,N＇-bis-（1-naphthl）-diphenyl-1,1＇-biphenyl-4,4＇-diamine,and AlQ is tris-（8-hydroxyquinoline） aluminum.The cathode of Ce （11 nm）/Au （15 nm） has a transparency of 46%,and the TOLED with it achieves the highest luminescence efficiencies：a current efficiency of 0.91 cd/A at 13.7 V and a peak power efficiency of 0.28 lm/W at 9 V.The turn-on voltage is 3.0 V.The Ce/Au cathode is both chemically and electrically stable.
文摘ith the aid of a fibre optical device, the profile of plasma parameters, such as plasma length and noise power spectrum, in a normally enclosed TM 010 cavity was probed. Experimental results show that the physical length of a plasma is linearly related to the microwave power applied and that the profile of noise power spectra varies significantly along the length of a plasma.
文摘Objectives: Peripheral neuropathy (PN) is a significant contributor to disability in the elderly. It is also one of the most prevalent complications of type 2 diabetes, prediabetes and metabolic syndrome. PN is commonly associated with pain, numbness, tingling, burning, and cramping in the feet and legs. Current treatment options are limited to controlling pain, seizures and use of antidepressant medications. These treatments have undesirable side effects and don’t stop PN progression. Here we utilized a combination of individual-specific modalities to improve local circulation and relieve PN symptoms. Methods: We conducted an open-label, multicenter pilot trial with 34 subjects (19 males and 15 females ranging from 40 - 85 years of age). All of the participants were diagnosed with peripheral neuropathy and had bilateral symptoms in their feet, and many reported the same symptoms (pain, numbness, tingling, burning, and cramping) in their lower legs. The duration of symptoms ranged from four months to over six years. On Day 0, subjects were given a 90-day supply of the oral supplement with dosing instructions and a LED light therapy device. They also received three platelet-rich plasma (PRP) injections in their lower extremities. Subjects also received an extracorporeal shockwave therapy (ESWT) treatment for each foot and subsequently twice per week for the first six weeks, then once weekly for the duration of the study. Subjects filled out the Brief Pain Index (BPI) at weekly intervals. On Day 90, subjects completed the Patient Global Impression of Change (PGIC) survey. Results: There were significant responses to pain, as evidenced by BPI scores at weeks 8, 9, 10 and 11 (p = 0.02, 0.01, 0.02, and 0.003, respectively). Analysis of the final day PGIC survey showed a favorable outcome for 73% of participants (p = 0.003), with the majority reporting Very Much Improved. Conclusions: By utilizing a multi-modality treatment protocol that includes PRP, LED light therapy, ESWT and an oral dietary supplement, we observed significant reductions in BPI scores. Quality of life and their overall impression of change (PGIC) were significantly improved, and there were no significant side effects.
基金supported by the National Natural Science Foundation of China(22176058)the Science and Technology Commission of Shanghai Municipality(24DX1400200,22ZR1416800,23ZR1416100)+1 种基金the Program of Introducing Talents of Discipline to Universities(B16017)the Fundamental Research Funds for the Central Universities(222201717003)。
文摘Ordinary metal salts have become a promising afterglow material because of the characteristics of wide sources,low cost,and easy availability.However,their extremely weak afterglow efficiency makes them rarely used in practical applications.In this study,we proposed a ligand engineering strategy to greatly enhance the afterglow efficiency of metal salts.Al_(2)(SO_(4))_(3),as a typical metal salt,has only a photoluminescence quantum yield(PL QY)as low as 0.1%and an unmeasurable phosphorescent QY.After doping with dual organic ligands,the PL QY of Al_(2)(SO_(4))_(3)has increased by nearly 200 times,reaching 19.90%.Meanwhile,the afterglow intensity of Al_(2)(SO_(4))_(3)has increased by approximately 20 times,accompanied by a great increase in phosphorescent lifetime from 416.15 to 2870.08 ms(a about 7-time increase).The enhancement mechanism of afterglow efficiency is ascribed to the fact that the excited electrons from the dual ligands can be directly captured by oxygen defects(trap),then transferred to the emitters(Al^(3+)ions),and ultimately achieving efficient afterglow luminescence.This study utilizes ligand engineering strategy to improve the afterglow luminescence efficiency of metal salts,achieving their applications in deep ultraviolet(UV)-excited light emitting devices and visual ethylene glycol recognition.
文摘A systematic study has been conducted on microcavity organic light emitting diodes(OLEDs)based on green,red and blue phosphorescent emitters to elucidate the microcavity effects for different color emitters.We found that the luminance output is determined by the reflectivity of the semitransparent electrode and the photopic response of the green,red and blue emitters.While the luminance enhancements of blue and red phosphorescent microcavity devices are small,a current efficiency as high as 224 cd A21 is obtained in the green phosphorescent microcavity OLEDs.
文摘The debate over how one of the most popular osteoarthritis treatments should be federally regulated could change,thanks to a Cornell University study and a new device that provides a better understanding of the science behind hyaluronic acid(HA)injections.
基金European Union under the REFRESH-Research Excellence For REgion Sustainability and High-tech Industries project number CZ.10.03.01/00/22003/0000048 via the Operational Programme Just TransitionMinistry of Education,Youth,and Sports of the Czech Republic con-ducted by the VSB-Technical University of Ostrava,under grant no.SP2024/081+1 种基金projects CI-CECO(LA/P/0006/2020,UIDB/50011/2020&UIDP/50011/2020)and Di-giAqua(PTDC/EEI-EEE/0415/2021)financed by national funds through the(Portuguese Science and Technology Foundation/MCTES(FCT I.P.)).
文摘A mixture of polydimethylsiloxane (PDMS) doped with phosphor particles can be found across diverse industries having different applications. This mixture plays a particularly important role in the field of lighting, white light-emitting diodes (LED's), flexible display devices, anti-counterfeiting (AC) solutions, luminescence thermometers and many types of sensors. The field of mechanoluminescence and biomedical are booming and there is also potential for visible light communication (VLC). In this comprehensive review, the basic characteristics of PDMS and a list of selected phosphors suitable for creating a mixture of PDMS and phosphor are presented. The summary and a detailed overview of the implemented applications of this perspective mixture over the last decade is presented as well.
