With the universal test machine and temperature test chamber, the effect of pressure and temperature on the behavior of 1-3 and 1-3-2 piezocomposites prepared with PZT/epoxy in our lab has been investigated through el...With the universal test machine and temperature test chamber, the effect of pressure and temperature on the behavior of 1-3 and 1-3-2 piezocomposites prepared with PZT/epoxy in our lab has been investigated through electrical impedance and dielectric analysis. The permittivity, resonant frequency and dielectric loss of the composites have been measured under vertical stress and temperature, and the variety of the material properties under pressure and temperature could also be obtained. The pressure and temperature stability of the composites have been assessed through experiments. The data of these two types of composites indicated that the stability of 1-342 composite with pressure was better than that of 1-3 composite, and two composites have almost the same dielectric stability with temperature. However, 1-3-2 composite showed slower frequency variation than 1-3 composite.展开更多
Largescale vaporsolid synthesis of ultralong silicon nitride （Si3N4） nanowires was achieved by using simple thermal evaporation of mixture powders of active carbon and monoxide silicon. The products were charac teri...Largescale vaporsolid synthesis of ultralong silicon nitride （Si3N4） nanowires was achieved by using simple thermal evaporation of mixture powders of active carbon and monoxide silicon. The products were charac terized by Xray diffraction, scanning electron microscopy, energydispersive Xray spectroscopy, and transmission electron microscopy. The results suggest that the silicon nitride nanowires have a smooth surface, with lengths of up to several hundreds of microns and diameters of 100300 nm. A detailed study of both the chemical and structural composition was performed. Such ultralong sil icon nitride nanowires demonstrate potential applications as materials for constructing nanoscale devices and as reinforcement in advanced composites.展开更多
Straight carbon nanotubes (CNTs) were achieved by simple thermal chemical vapor deposition(STCVD) catalyzed by Mo-Fe alloy catalyst on silica supporting substrate at 700℃. High-resolution transmission electron micros...Straight carbon nanotubes (CNTs) were achieved by simple thermal chemical vapor deposition(STCVD) catalyzed by Mo-Fe alloy catalyst on silica supporting substrate at 700℃. High-resolution transmission electron microscopy images show that the straight CNTs are well graphitized with no attached amorphous carbon. Mo-Fe alloy catalyst particles play a very crucial role in the growth of straight CNTs. The straight carbon nanotubes contain much less defects than the curved nanotubes and might have potential applications for nanoelectrical devices in the future. The simple synthesis of straight CNTs may have benefit for large-scale productions.展开更多
The characterization of electrical property of multi-walled carbon nanotubes (MWCNTs) on a nanometer scale is essential for their potential application in nano-electronic devices. The MWCNTs were synthesized on Fe2O3/...The characterization of electrical property of multi-walled carbon nanotubes (MWCNTs) on a nanometer scale is essential for their potential application in nano-electronic devices. The MWCNTs were synthesized on Fe2O3/SiO2/Si substrate and Pt plate substrate by simple thermal chemical vapor deposition (STCVD) technique and the electrical measurements of individual MWCNT grown on silicon substrate and Pt plate substrate were performed by home-made 'nano-manipulator', respectively. According to current-voltage curves obtained in the experiments the current density that the MWCNTs can carry is calculated to be about 107 A/cm2, which is much larger than that of normal metals.展开更多
Y-shaped structure was synthesized by ethanol catalytic combustion(ECC) technique on the copper plate substrate, without directly seeding catalyst into the flame. The as-grown Y-junction carbon nanofibres were investi...Y-shaped structure was synthesized by ethanol catalytic combustion(ECC) technique on the copper plate substrate, without directly seeding catalyst into the flame. The as-grown Y-junction carbon nanofibres were investigated by transmission electron microscopy (TEM). The very common laboratory ethanol burner was used for synthesizing carbon nanofibres. Two kinds of the catalyst precursor, which are iron nitrate (Fe(NO3)3) and nickel nitrate (Ni(NO3)2), were respectively employed to assist the formation of Y-junction carbon nanofibres. TEM analysis confirm the formation of Y-junction in the coiled and noncoiled carbon nanofibres. The type of the catalyst is found to be crucial to grow different Y-junction carbon nanofibres. Different Y-shaped structure may possess different mechanical and electronic properties. These three-terminal nanofibres provide the nanoelectronics community with a novel material for the development of molecular-scale electronic devices.展开更多
Bamboo-like carbon nanotubes were synthesized by ethanol catalytic combustion (ECC) technique with combustion method. Copper plate was employed as substrate, ethanol as carbon source, and iron chloride as catalyst pre...Bamboo-like carbon nanotubes were synthesized by ethanol catalytic combustion (ECC) technique with combustion method. Copper plate was employed as substrate, ethanol as carbon source, and iron chloride as catalyst precursor. The as-grown black powder was characterized by means of scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the thinner bamboo-like carbon nanotubes have a relatively good structure that the compartment layers are more regular, while the thicker carbon nanotubes have a relatively irregular bamboo-like structure; the proposed method is simple to synthesize bamboo-like carbon nanotubes and has some advantages, such as flexible synthesis conditions, simple setup, and environment-friendly.展开更多
A simple growth technique of carbon nanotubes (CNTs) by combustion of ethanol was developed. In the experiment, copper plate was employed as substrate, nickel nitrate (Ni(NO3)2) and nickel chloride (NiCl2) as catalyst...A simple growth technique of carbon nanotubes (CNTs) by combustion of ethanol was developed. In the experiment, copper plate was employed as substrate, nickel nitrate (Ni(NO3)2) and nickel chloride (NiCl2) as catalyst precursor, and ethanol as carbon source. The cleaned copper substrate was dipped into catalyst precursor solution for mounting catalyst precursor particles. The dip-coated substrate was then placed into ethanol flame for about 10 min after drying. The black wool-like production grown on copper plate was obtained. This route is called an ethanol catalytic combustion(ECC) process. The black powders were characterized by means of scanning electron microscopy(SEM), transmission electron microscopy(TEM), energy dispersive X-ray spectrometer(EDS) and Raman spectroscopy. The results show that the techique is much simpler and more economical to meet the future broader applications.展开更多
Iron nitrate, nickel nitrate and cobalt nitrate were used as catalyst precursors to study their effects on carbon nanowires synthesized by ethanol catalytic combustion (ECC) process. The as-grown carbon nanowires were...Iron nitrate, nickel nitrate and cobalt nitrate were used as catalyst precursors to study their effects on carbon nanowires synthesized by ethanol catalytic combustion (ECC) process. The as-grown carbon nanowires were characterized by means of scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that relatively uniform nanowires will be formed when the catalyst precursor is iron nitrate; while helical structure or disordered structure will be formed when the catalyst precursor is nickel nitrate or cobalt nitrate.展开更多
This paper presents a development process of software with Graphic User Interface (GUI) for monitoring temperature in a Zigbee Wireless Network. The software framework design was introduced and analyzed in detail. In ...This paper presents a development process of software with Graphic User Interface (GUI) for monitoring temperature in a Zigbee Wireless Network. The software framework design was introduced and analyzed in detail. In this paper, we wrote the software with C++ codes in Microsoft Foundation Class (MFC) programming of Visual C++ 6.0, which applied in wireless communication algorithms. Software test results show that temperature of Zibee network was real-time displayed by both text and curve, which achieved wireless temperature monitoring to Zigbee network.展开更多
This paper introduces a mobile phone short message control method in smart home based on GSM (Global System for Mobile communications). AT commands and the system structure is illustrated in detail. The hardware syste...This paper introduces a mobile phone short message control method in smart home based on GSM (Global System for Mobile communications). AT commands and the system structure is illustrated in detail. The hardware system including STC89C51 and TC35i is presented. The software framework is also analyzed clearly in this paper. In addition, some other potential application areas and its direction of development in future are given at last.展开更多
This paper presents a solution to wireless light control system based on Zigbee. Overall design framework of the system was introduced and analyzed in detail, which contained realization of hardware design. The Zigbee...This paper presents a solution to wireless light control system based on Zigbee. Overall design framework of the system was introduced and analyzed in detail, which contained realization of hardware design. The Zigbee wireless light control system was established based on CC2430-chip of Texas Instruments (TI). In this paper, we achieved designing Printed Circuit Board (PCB) for sensor nodes as end device and coordinator in Protel DXP 2004 and also wrote C codes in IAR embedded workbench development tool to form wireless network. Test results of system show that lights on end device or router in Zigbee wireless sensor networks (WSN) can be controlled by another switch on coordinator, which achieved remotely wireless intelligence light control.展开更多
The carbon nanotube (CNT) growth of iron oxide-deposited trench-patterns and the locally-ordered CNT arrays on silicon substrate were achieved by simple thermal chemical vapor deposition(STCVD) of ethanol vapor. The C...The carbon nanotube (CNT) growth of iron oxide-deposited trench-patterns and the locally-ordered CNT arrays on silicon substrate were achieved by simple thermal chemical vapor deposition(STCVD) of ethanol vapor. The CNTs were uniformly synthesized with good selectivity on trench-patterned silicon substrates. This fabrication process is compatible with currently used semiconductor-processing technologies, and the carbon-nanotube fabrication process can be widely applied for the development of electronic devices using carbon-nanotube field emitters as cold cathodes and can revolutionize the area of field-emitting electronic devices. The site-selective growth of CNT from an iron oxide nanoparticle catalyst patterned were also achieved by drying-mediated self-assembly technique. The present method offers a simple and cost-effective method to grow carbon nanotubes with self-assembled patterns.展开更多
We present a simple method to synthesize Pb（OH）2 nanorods by solution-phase reaction. Rod-like lead hydroxide precipitates are obtained by mixing lead nitrate with a concentration of about 0.01 M and potassium hydro...We present a simple method to synthesize Pb（OH）2 nanorods by solution-phase reaction. Rod-like lead hydroxide precipitates are obtained by mixing lead nitrate with a concentration of about 0.01 M and potassium hydroxide with concentration of about O.03 M in an aqueous solution. Sodium chloride as an additive is premixed with the lead nitrate aqueous solution. The presence of chloride ions in the precursor solution results in the rod-like morphology of lead hydroxide precipitates. The growth mechanism of the lead hydroxide nanorods is discussed.展开更多
Perovskite Solar Cells(PSCs)have attracted considerable attention because of their unique features and high efficiency.However,the stability of perovskite solar cells remains to be improved.In this study,we modified t...Perovskite Solar Cells(PSCs)have attracted considerable attention because of their unique features and high efficiency.However,the stability of perovskite solar cells remains to be improved.In this study,we modified the TiO_(2)Electron Transport Layer(ETL)interface with PbCl_(2).The efficiency of the perovskite solar cells with carbon electrodes increased from 11.28%to 13.34%,and their stability obviously improved.The addition of PbCl_(2)had no effect on the morphology,crystal structure,and absorption property of the perovskite absorber layer.However,it affected the band energy level alignment of the solar cells and accelerated the electron extraction and transfer at the interface between the perovskite layer and the ETL,thus enhancing the overall photovoltaic performance.The interfacial modification of ETL with PbCl_(2)is a promising way for the potential commercialization of low-cost carbon electrode-based perovskite solar cells.展开更多
In recent years,Perovskite Light-Emitting Diodes(PeLEDs)have received considerable attention in academia.However,with the development of PeLEDs,commercial applications of full-color PeLED technology are largely limite...In recent years,Perovskite Light-Emitting Diodes(PeLEDs)have received considerable attention in academia.However,with the development of PeLEDs,commercial applications of full-color PeLED technology are largely limited by the progress of blue-emitting devices,due to the uncontrollably accurate composition,unstable properties,and low luminance.In this article,we add Cesium chloride(CsCl)to the quasi-two-dimensional(quasi-2D)perovskite precursor solution and achieve the relatively blue shifts of PeLED emission peak by introducing chloride ions for photoluminescence(PL)and electroluminescence(EL).We also found that the introduction of chlorine ions can make quasi-2D perovskite films thinner with smoother surface of 0.408 nm.It is interesting that the EL peaks and intensities of PeLED are adjustable under different driving voltages in high concentration chlorine-added perovskite devices,and different processes of photo-excited,photo-quenched,and photo-excited occur sequentially with the increasing driving voltage.Our work provides a path for demonstrating full-color screens in the future.展开更多
Novel straight silicon oxide [SiO x (1<x<2)] nanorod Y junctions have been synthesized on Si plate by thermal evaporation of mixed powders of silica and carbon nanofibers at 1300°C and condensation on a Si ...Novel straight silicon oxide [SiO x (1<x<2)] nanorod Y junctions have been synthesized on Si plate by thermal evaporation of mixed powders of silica and carbon nanofibers at 1300°C and condensation on a Si substrate without assistance of any catalyst. The synthesized samples were characterized by means of scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy. The results suggested that the straight nanorod Y junctions are amorphous and consist only of elements Si and O, and these rods with diameters about 50–200 nm have a neat smooth surface. The growth of such silicon oxide nanorods may be a result of the second nucleation on the surface of rods causing a change in the growth direction of silicon oxide nanorods developed.展开更多
Green Perovskite Light-Emitting Diodes(PeLEDs)have attracted wide attention for full spectrum displays.However,the inferior film morphology and luminescence property of quasi-two-dimensional(quasi-2D)perovskite layers...Green Perovskite Light-Emitting Diodes(PeLEDs)have attracted wide attention for full spectrum displays.However,the inferior film morphology and luminescence property of quasi-two-dimensional(quasi-2D)perovskite layers limit the photoelectric property of the PeLEDs.In this paper,the effect of strontium(Sr)doped in quasi-2D perovskite layers is investigated to obtain a high-quality active layer.The morphologies and optical properties of Sr-doped quasi-2D perovskite films with different concentrations are studied.With the addition of strontium,more low-dimensional-layer perovskite phases(n D 2 and n D 3)appear in quasi-2D perovskite films,providing efficient intraband carrier funneling pathway and facilitating radiative recombination.The photoluminescence(PL)peak intensity of optimized Sr-doped quasi-2D perovskite layers increases 50%compared with the non-strontium counterpart.Moreover,green PeLEDs based on a Sr-doped quasi-2D perovskite layer reach a maximum luminance(Lmax)of 2943.77 cd/m^(2),which is three times of the control device.The electroluminescence(EL)peaks of Maximum External Quantum Efficiency(MEQE)and Lmax of Sr-doped PeLEDs exhibite a slight shift,indicating the excellent stability and performance of Sr-doped devices.The optimized device can continuously operate for 360 s at MEQE driving voltage,resulting in a half-lifetime of60 s,which is 3-fold greater than that of the control PeLEDs.展开更多
基金supported by the National Natural Science Foundation of China (No.60871038)the Beijing Natural Science Foundation (No.4092014)Foundation of PHR(IHLB)
文摘With the universal test machine and temperature test chamber, the effect of pressure and temperature on the behavior of 1-3 and 1-3-2 piezocomposites prepared with PZT/epoxy in our lab has been investigated through electrical impedance and dielectric analysis. The permittivity, resonant frequency and dielectric loss of the composites have been measured under vertical stress and temperature, and the variety of the material properties under pressure and temperature could also be obtained. The pressure and temperature stability of the composites have been assessed through experiments. The data of these two types of composites indicated that the stability of 1-342 composite with pressure was better than that of 1-3 composite, and two composites have almost the same dielectric stability with temperature. However, 1-3-2 composite showed slower frequency variation than 1-3 composite.
基金supported by the Key Program of the National Natural Science Foundation of China(No.19934003)the Grand Program of Natural Science Research of Anhui Education Department(No.ZD2007003-1)+1 种基金the Natural Science Research Program of Universities and Colleges of Anhui Province(No.KJ2008A19ZC)the Opening Program of Cultivating Baseof Anhui Key Laboratory of Spintronics and Nano-materials(No.2012YKF10)
文摘Largescale vaporsolid synthesis of ultralong silicon nitride （Si3N4） nanowires was achieved by using simple thermal evaporation of mixture powders of active carbon and monoxide silicon. The products were charac terized by Xray diffraction, scanning electron microscopy, energydispersive Xray spectroscopy, and transmission electron microscopy. The results suggest that the silicon nitride nanowires have a smooth surface, with lengths of up to several hundreds of microns and diameters of 100300 nm. A detailed study of both the chemical and structural composition was performed. Such ultralong sil icon nitride nanowires demonstrate potential applications as materials for constructing nanoscale devices and as reinforcement in advanced composites.
基金Project(KM200510772013) supported by the Science and Technology Development Program of Education Committee of Beijing City Project (2005-2007) supported by the Academic Innovative Team Program(Novel Sensor and Materials: Nanodevice and Nanomaterials) of Education Committee of Beijing City
文摘Straight carbon nanotubes (CNTs) were achieved by simple thermal chemical vapor deposition(STCVD) catalyzed by Mo-Fe alloy catalyst on silica supporting substrate at 700℃. High-resolution transmission electron microscopy images show that the straight CNTs are well graphitized with no attached amorphous carbon. Mo-Fe alloy catalyst particles play a very crucial role in the growth of straight CNTs. The straight carbon nanotubes contain much less defects than the curved nanotubes and might have potential applications for nanoelectrical devices in the future. The simple synthesis of straight CNTs may have benefit for large-scale productions.
基金Project(KM200510772013) supported by the Science and Technology Development Program of Education Committee of Beijing City Project (2005 - 2007) supported by the Academic Innovative Team Program (Novel Sensor and Materials: Nanodevice and Nanomaterials) of Education Committee of Beijing City
文摘The characterization of electrical property of multi-walled carbon nanotubes (MWCNTs) on a nanometer scale is essential for their potential application in nano-electronic devices. The MWCNTs were synthesized on Fe2O3/SiO2/Si substrate and Pt plate substrate by simple thermal chemical vapor deposition (STCVD) technique and the electrical measurements of individual MWCNT grown on silicon substrate and Pt plate substrate were performed by home-made 'nano-manipulator', respectively. According to current-voltage curves obtained in the experiments the current density that the MWCNTs can carry is calculated to be about 107 A/cm2, which is much larger than that of normal metals.
基金Project(KM200510772013) supported by Beijing City Education Committee Science and Technology Development Program Project(2005-2007) supported by Beijing City Education Committee Academic Innovative Team Program
文摘Y-shaped structure was synthesized by ethanol catalytic combustion(ECC) technique on the copper plate substrate, without directly seeding catalyst into the flame. The as-grown Y-junction carbon nanofibres were investigated by transmission electron microscopy (TEM). The very common laboratory ethanol burner was used for synthesizing carbon nanofibres. Two kinds of the catalyst precursor, which are iron nitrate (Fe(NO3)3) and nickel nitrate (Ni(NO3)2), were respectively employed to assist the formation of Y-junction carbon nanofibres. TEM analysis confirm the formation of Y-junction in the coiled and noncoiled carbon nanofibres. The type of the catalyst is found to be crucial to grow different Y-junction carbon nanofibres. Different Y-shaped structure may possess different mechanical and electronic properties. These three-terminal nanofibres provide the nanoelectronics community with a novel material for the development of molecular-scale electronic devices.
基金Project(KM200510772013) supported by the Science and Technology Development Program of Education Committee of Beijing City Project(2005-2007) supported by the Academic Innovative Team Porgram (Novel Sensor and Materials: Nanodevice and Nanomaterials) of Education Committee of Beijing City
文摘Bamboo-like carbon nanotubes were synthesized by ethanol catalytic combustion (ECC) technique with combustion method. Copper plate was employed as substrate, ethanol as carbon source, and iron chloride as catalyst precursor. The as-grown black powder was characterized by means of scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the thinner bamboo-like carbon nanotubes have a relatively good structure that the compartment layers are more regular, while the thicker carbon nanotubes have a relatively irregular bamboo-like structure; the proposed method is simple to synthesize bamboo-like carbon nanotubes and has some advantages, such as flexible synthesis conditions, simple setup, and environment-friendly.
基金Project (KM200510772013) supported by the Science and Technology Development Program of Education Committee of Beijing City Project (2005-2007) supported by Academic Innovative Team Program (Novel Sensor and Materials: Nanodevice and Nanomaterials) of Education Committee of Beijing City
文摘A simple growth technique of carbon nanotubes (CNTs) by combustion of ethanol was developed. In the experiment, copper plate was employed as substrate, nickel nitrate (Ni(NO3)2) and nickel chloride (NiCl2) as catalyst precursor, and ethanol as carbon source. The cleaned copper substrate was dipped into catalyst precursor solution for mounting catalyst precursor particles. The dip-coated substrate was then placed into ethanol flame for about 10 min after drying. The black wool-like production grown on copper plate was obtained. This route is called an ethanol catalytic combustion(ECC) process. The black powders were characterized by means of scanning electron microscopy(SEM), transmission electron microscopy(TEM), energy dispersive X-ray spectrometer(EDS) and Raman spectroscopy. The results show that the techique is much simpler and more economical to meet the future broader applications.
基金Project (KM200510772013) supported by the Science and Technology Development Program of Education Committee of Beijing City Project(2005-2007) supported by Academic Innovative Team Program (Novel Sensor and Materials: Nanodevice and Nanomaterials) of Education Committee of Beijing City
文摘Iron nitrate, nickel nitrate and cobalt nitrate were used as catalyst precursors to study their effects on carbon nanowires synthesized by ethanol catalytic combustion (ECC) process. The as-grown carbon nanowires were characterized by means of scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that relatively uniform nanowires will be formed when the catalyst precursor is iron nitrate; while helical structure or disordered structure will be formed when the catalyst precursor is nickel nitrate or cobalt nitrate.
文摘This paper presents a development process of software with Graphic User Interface (GUI) for monitoring temperature in a Zigbee Wireless Network. The software framework design was introduced and analyzed in detail. In this paper, we wrote the software with C++ codes in Microsoft Foundation Class (MFC) programming of Visual C++ 6.0, which applied in wireless communication algorithms. Software test results show that temperature of Zibee network was real-time displayed by both text and curve, which achieved wireless temperature monitoring to Zigbee network.
文摘This paper introduces a mobile phone short message control method in smart home based on GSM (Global System for Mobile communications). AT commands and the system structure is illustrated in detail. The hardware system including STC89C51 and TC35i is presented. The software framework is also analyzed clearly in this paper. In addition, some other potential application areas and its direction of development in future are given at last.
文摘This paper presents a solution to wireless light control system based on Zigbee. Overall design framework of the system was introduced and analyzed in detail, which contained realization of hardware design. The Zigbee wireless light control system was established based on CC2430-chip of Texas Instruments (TI). In this paper, we achieved designing Printed Circuit Board (PCB) for sensor nodes as end device and coordinator in Protel DXP 2004 and also wrote C codes in IAR embedded workbench development tool to form wireless network. Test results of system show that lights on end device or router in Zigbee wireless sensor networks (WSN) can be controlled by another switch on coordinator, which achieved remotely wireless intelligence light control.
基金Project(KM200510772013) supported by the Beijing City Education Committee Science and Technology Development ProgramProject( 2005?2007) supported by the Academic Innovative Team Program(Novel Sensor & Materials: Nanodevice & Nanomaterials) of Education Committee of Beijing City
文摘The carbon nanotube (CNT) growth of iron oxide-deposited trench-patterns and the locally-ordered CNT arrays on silicon substrate were achieved by simple thermal chemical vapor deposition(STCVD) of ethanol vapor. The CNTs were uniformly synthesized with good selectivity on trench-patterned silicon substrates. This fabrication process is compatible with currently used semiconductor-processing technologies, and the carbon-nanotube fabrication process can be widely applied for the development of electronic devices using carbon-nanotube field emitters as cold cathodes and can revolutionize the area of field-emitting electronic devices. The site-selective growth of CNT from an iron oxide nanoparticle catalyst patterned were also achieved by drying-mediated self-assembly technique. The present method offers a simple and cost-effective method to grow carbon nanotubes with self-assembled patterns.
文摘We present a simple method to synthesize Pb（OH）2 nanorods by solution-phase reaction. Rod-like lead hydroxide precipitates are obtained by mixing lead nitrate with a concentration of about 0.01 M and potassium hydroxide with concentration of about O.03 M in an aqueous solution. Sodium chloride as an additive is premixed with the lead nitrate aqueous solution. The presence of chloride ions in the precursor solution results in the rod-like morphology of lead hydroxide precipitates. The growth mechanism of the lead hydroxide nanorods is discussed.
基金supported by the National Natural Science Foundation of China(Nos.61875186,61975196,and 61674140)Chinese Academy of Sciences(CAS)The World Academy of Sciences(TWAS)(CASTWAS)scholarship。
文摘Perovskite Solar Cells(PSCs)have attracted considerable attention because of their unique features and high efficiency.However,the stability of perovskite solar cells remains to be improved.In this study,we modified the TiO_(2)Electron Transport Layer(ETL)interface with PbCl_(2).The efficiency of the perovskite solar cells with carbon electrodes increased from 11.28%to 13.34%,and their stability obviously improved.The addition of PbCl_(2)had no effect on the morphology,crystal structure,and absorption property of the perovskite absorber layer.However,it affected the band energy level alignment of the solar cells and accelerated the electron extraction and transfer at the interface between the perovskite layer and the ETL,thus enhancing the overall photovoltaic performance.The interfacial modification of ETL with PbCl_(2)is a promising way for the potential commercialization of low-cost carbon electrode-based perovskite solar cells.
基金supported by the National Key Research and Development Program of China(No.2018YFB2200103)the National Natural Science Foundation of China(Nos.61875186 and 61975196)+2 种基金the Project of the Natural Science Foundation of Beijing(No.Z160002)the Key Research Projects of Beijing Information Science and Technology University(BISTU)(Nos.2019-22,2019-23,2019-27)the Beijing Key Laboratory for Sensors of BISTU(No.2019CGKF007)。
文摘In recent years,Perovskite Light-Emitting Diodes(PeLEDs)have received considerable attention in academia.However,with the development of PeLEDs,commercial applications of full-color PeLED technology are largely limited by the progress of blue-emitting devices,due to the uncontrollably accurate composition,unstable properties,and low luminance.In this article,we add Cesium chloride(CsCl)to the quasi-two-dimensional(quasi-2D)perovskite precursor solution and achieve the relatively blue shifts of PeLED emission peak by introducing chloride ions for photoluminescence(PL)and electroluminescence(EL).We also found that the introduction of chlorine ions can make quasi-2D perovskite films thinner with smoother surface of 0.408 nm.It is interesting that the EL peaks and intensities of PeLED are adjustable under different driving voltages in high concentration chlorine-added perovskite devices,and different processes of photo-excited,photo-quenched,and photo-excited occur sequentially with the increasing driving voltage.Our work provides a path for demonstrating full-color screens in the future.
基金Supported by the Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijingthe Program of Science & Technol-ogy Activity for Chinese Homecoming Fellow AbroadResearch Program of Beijing Key Laboratory for Sensor (Grant No. KM200810772009)
文摘Novel straight silicon oxide [SiO x (1<x<2)] nanorod Y junctions have been synthesized on Si plate by thermal evaporation of mixed powders of silica and carbon nanofibers at 1300°C and condensation on a Si substrate without assistance of any catalyst. The synthesized samples were characterized by means of scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy. The results suggested that the straight nanorod Y junctions are amorphous and consist only of elements Si and O, and these rods with diameters about 50–200 nm have a neat smooth surface. The growth of such silicon oxide nanorods may be a result of the second nucleation on the surface of rods causing a change in the growth direction of silicon oxide nanorods developed.
基金supported by the National Natural Science Foundation of China (Nos.61875186,61975196,and 61674140)。
文摘Green Perovskite Light-Emitting Diodes(PeLEDs)have attracted wide attention for full spectrum displays.However,the inferior film morphology and luminescence property of quasi-two-dimensional(quasi-2D)perovskite layers limit the photoelectric property of the PeLEDs.In this paper,the effect of strontium(Sr)doped in quasi-2D perovskite layers is investigated to obtain a high-quality active layer.The morphologies and optical properties of Sr-doped quasi-2D perovskite films with different concentrations are studied.With the addition of strontium,more low-dimensional-layer perovskite phases(n D 2 and n D 3)appear in quasi-2D perovskite films,providing efficient intraband carrier funneling pathway and facilitating radiative recombination.The photoluminescence(PL)peak intensity of optimized Sr-doped quasi-2D perovskite layers increases 50%compared with the non-strontium counterpart.Moreover,green PeLEDs based on a Sr-doped quasi-2D perovskite layer reach a maximum luminance(Lmax)of 2943.77 cd/m^(2),which is three times of the control device.The electroluminescence(EL)peaks of Maximum External Quantum Efficiency(MEQE)and Lmax of Sr-doped PeLEDs exhibite a slight shift,indicating the excellent stability and performance of Sr-doped devices.The optimized device can continuously operate for 360 s at MEQE driving voltage,resulting in a half-lifetime of60 s,which is 3-fold greater than that of the control PeLEDs.
