A new functionalized heteroleptic iridium complex coordinated with 1-phenylisoquinoline (1-piq) and a functionalized fl-diketone (G1), Ir(1-piq)2G1, was synthesized and characterized by 1H-NMR, mass spectrometry...A new functionalized heteroleptic iridium complex coordinated with 1-phenylisoquinoline (1-piq) and a functionalized fl-diketone (G1), Ir(1-piq)2G1, was synthesized and characterized by 1H-NMR, mass spectrometry and elemental analysis. The larger conjugation of the replacement of acetylacetone (acac) by a functionalizedβ-diketonate ligand led to a significant decrease in the HOMO level toward vacuum level, while Ir(1-piq)2G1 and Ir(1-piq)2(acac) showed red phosphorescent emissions of about 620 nm in dichloromethane solution. The phosphorescent polymer light-emitting devices were achieved, with the complexes incorporated with polyfluorene (PFO) as a host polymer doped with 30% of 5-(4-biphenylyl)-2-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) as electron transport material. The energy transfer mechanism of the devices was also discussed. The lower EL performance of Ir(1-piq)2G1 is ascribed to the inter-ligand energy transfer, indicating that it is important to control the energy level of the cyclometalated and ancillary ligands.展开更多
The aim of this paper is to present a new topology of a DC-DC power converter for conditioning the current and voltages behaviors of embarked energy sources used in electrical vehicles. The fuel cells in conjunction w...The aim of this paper is to present a new topology of a DC-DC power converter for conditioning the current and voltages behaviors of embarked energy sources used in electrical vehicles. The fuel cells in conjunction with ultra-capacitors have been chosen as the power supply. The originality of the proposed converter is to use a variable voltage of the DC bus of the vehicle. The goal is to allow a better energy management of the embedded sources onboard the vehicle by improving its energy efficiency. After presenting and explaining the topology of the converter, some simulation and experiments results are shown to highlight its different operation modes.展开更多
As a new member of thin-film solar cells, the perovskite solar ceils have inspired a new research hot in new photoelectric materials and devices, and have given a new energy to the photovoltaic science. Currently, var...As a new member of thin-film solar cells, the perovskite solar ceils have inspired a new research hot in new photoelectric materials and devices, and have given a new energy to the photovoltaic science. Currently, various device structures, including mesoporous and planar, with and without hole transport material have been developed. In this review, much focus has been addressed to the deposition of high-quality perovskite films, structural optimization, and interface engineering as well as the understanding of the charge generation, transport, and recombination mechanisms of the devices. Furthermore, cost, stability, and environment issues of the cell are also discussed for commercial application.展开更多
There has been an increasing demand for high-performance and cost-effective organic electron-transport materials for organic light-emitting diodes (OLEDs). In this contribution, we present a simple compound 3-(3-(...There has been an increasing demand for high-performance and cost-effective organic electron-transport materials for organic light-emitting diodes (OLEDs). In this contribution, we present a simple compound 3-(3-(4,6-diphenyl-l,3,5-triazin-2-yl)phenyl)-1,10-phenanthroline through the facile Pd-catalyzed coupling of a triphenyltriazine boronic ester with 3-hromo-1,10-phenanthroline. It shows a high Tg of 112℃. The ultraviolet photoelectron spectroscopy measurements reveal a deep HOMO level of -6.5 eV. The LUMO level is derived as -3.0 eV, based on the optical bandgap. The low-temperature solid-state phosphorescent spectrum gives a triplet energy of -2.36eV. n-Doping with 8-hydroxyquinolatolithium (Liq, 1:1) leads to considerably improved electron mobility of 5.2 × 10 -6 -5.8 × 10 -5 cm2 v-1 S-1 at E=(2-5) × 10 5Vcm -1, in contrast with the triarylphosphine oxide- phenantroline molecular conjugate we reported previously. It has been shown that through optimizing the device structure and hence suppressing polaron-exciton annihilation, introducing this single Liq-doped electron-transport layer could offer high-efficiency and stable phosphorescent OLEDs.展开更多
It is necessary to evaluate the interactions between the different functional layers in optoelectronic devices to optimize device performance.Recently,the I-rich allinorganic perovskite CsPbI2 Br has attracted tremend...It is necessary to evaluate the interactions between the different functional layers in optoelectronic devices to optimize device performance.Recently,the I-rich allinorganic perovskite CsPbI2 Br has attracted tremendous attention for use in solar cell applications because of its suitable band gap and favorable photo and thermal stabilities.It has been reported that the undesirable phase degradation of the photoactiveαphase CsPbI2 Br to the non-perovskiteδphase could be triggered by high humidity.To obtain stable devices,it is thus important to protect CsPbI2 Br from moisture.In this paper,CuI,a non-hygroscopic p-type hole-transporting material,is found to induce the phase degradation ofα-CsPbI2 Br to theδ-CsPbI2 Br.The rate and extent of phase degradation of CsPbI2 Br are closely associated with the heating temperature and coverage of a Cu I granular capping layer.This discovery is different from the widely reported water-induced phase degradation of CsPbI2 Br.Our work highlights the importance of careful selection of hole-transporting materials during the processing of I-rich all-inorganic CsPbX3(X=Br,I)perovskites to realize high-performance optoelectronic devices.展开更多
Rationally designed heterostructures provide attractive prospects for energy storage electrodes by combining different active materials with distinct electrochemical properties.Herein,through a phase separation strate...Rationally designed heterostructures provide attractive prospects for energy storage electrodes by combining different active materials with distinct electrochemical properties.Herein,through a phase separation strategy,a heterostructure of SnO_(2) encapsulated by amorphous Nb_(2)O_(5) is spontaneously synthesized.Insertion-type anode Nb_(2)O_(5) outer shell,playing as reaction containers and fast ionic pathways,physically inhibits the Sn atoms’migration and enhances the reaction kinetics.Moreover,strong chemical interactions are found at the SnO_(2)/Nb_(2)O_(5) interfaces,which ensure the solid encapsulation of the SnO_(2) cores even after 500 cycles.When used for lithium-ion batteries,this heterostructured anode exhibits high cycling stability with a capacity of 626 mAhg^(-1) after 1000 cycles at 2Ag^(-1)(85% capacity retention)and good rate performance with the capacity of 340 mAhg^(-1) at 8Ag^(-1).展开更多
In this work,efficient green electroluminescent(EL)devices with simplified device structure were prepared by doping trivalent terbium complex Tb(PMIP)3into hole block material Tm Py PB.The high triplet energy of T...In this work,efficient green electroluminescent(EL)devices with simplified device structure were prepared by doping trivalent terbium complex Tb(PMIP)3into hole block material Tm Py PB.The high triplet energy of Tm Py PB helps to confine excitons within light-emitting layer,while the electron transport characteristic of Tm Py PB facilitates the balance of carriers on Tb(PMIP)a3molecules.By optimizing the doping concentration of Tb(PMIP)a3and the thickness of each functional layer,highly efficient green EL device with the structure of ITO/Mo Oa3(3 nm)/TAPC(50 nm)/Tb(PMIP)a3(30 wt%):Tm Py PB(25 nm)/Tm Py PB(60 nm)/Li F(1 nm)/Al(100 nm)displayed pure Tb^3+ characteristic emission with maximum current efficiency,power efficiency and brightness up to 47.24 cd/A(external quantum efficiency(EQE)of 14.4%),43.63 lm/W and 1694 cd/m^2,respectively.At certain brightness of 100 cd/m^2,the device still maintained a current efficiency of 19.96 cd/A(EQE=6.1%).Such a device design strategy helps to improve the EL performances of Tb(PMIP)a3and to simplify device fabrication processes,thus reduce the fabrication cost.展开更多
基金Project(50803008) supported by the National Natural Science Foundation of ChinaProject(2002CB613403) supported by the Ministry of Science and Technology (MOST) of China+1 种基金Project(09JJ6085) supported by the Natural Science Foundation of Hunan Province,ChinaProject(08hjyh02) supported by the Open Project Program of Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education,China
文摘A new functionalized heteroleptic iridium complex coordinated with 1-phenylisoquinoline (1-piq) and a functionalized fl-diketone (G1), Ir(1-piq)2G1, was synthesized and characterized by 1H-NMR, mass spectrometry and elemental analysis. The larger conjugation of the replacement of acetylacetone (acac) by a functionalizedβ-diketonate ligand led to a significant decrease in the HOMO level toward vacuum level, while Ir(1-piq)2G1 and Ir(1-piq)2(acac) showed red phosphorescent emissions of about 620 nm in dichloromethane solution. The phosphorescent polymer light-emitting devices were achieved, with the complexes incorporated with polyfluorene (PFO) as a host polymer doped with 30% of 5-(4-biphenylyl)-2-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) as electron transport material. The energy transfer mechanism of the devices was also discussed. The lower EL performance of Ir(1-piq)2G1 is ascribed to the inter-ligand energy transfer, indicating that it is important to control the energy level of the cyclometalated and ancillary ligands.
文摘The aim of this paper is to present a new topology of a DC-DC power converter for conditioning the current and voltages behaviors of embarked energy sources used in electrical vehicles. The fuel cells in conjunction with ultra-capacitors have been chosen as the power supply. The originality of the proposed converter is to use a variable voltage of the DC bus of the vehicle. The goal is to allow a better energy management of the embedded sources onboard the vehicle by improving its energy efficiency. After presenting and explaining the topology of the converter, some simulation and experiments results are shown to highlight its different operation modes.
基金supported by Beijing Science and Technology Committee(Z131100006013003)the National Basic Research Program of China(2012CB932903)the National Natural Science Foundation of China(21173260,91233202)
文摘As a new member of thin-film solar cells, the perovskite solar ceils have inspired a new research hot in new photoelectric materials and devices, and have given a new energy to the photovoltaic science. Currently, various device structures, including mesoporous and planar, with and without hole transport material have been developed. In this review, much focus has been addressed to the deposition of high-quality perovskite films, structural optimization, and interface engineering as well as the understanding of the charge generation, transport, and recombination mechanisms of the devices. Furthermore, cost, stability, and environment issues of the cell are also discussed for commercial application.
基金supported by the National Key R&D Program of China(2016YFB0400701)NSFC-Guangdong Joint Program(U1301243)+1 种基金the National Basic Research Program of China(2015CB655000)support of Dongguan Major Special Project(2017215117010)
文摘There has been an increasing demand for high-performance and cost-effective organic electron-transport materials for organic light-emitting diodes (OLEDs). In this contribution, we present a simple compound 3-(3-(4,6-diphenyl-l,3,5-triazin-2-yl)phenyl)-1,10-phenanthroline through the facile Pd-catalyzed coupling of a triphenyltriazine boronic ester with 3-hromo-1,10-phenanthroline. It shows a high Tg of 112℃. The ultraviolet photoelectron spectroscopy measurements reveal a deep HOMO level of -6.5 eV. The LUMO level is derived as -3.0 eV, based on the optical bandgap. The low-temperature solid-state phosphorescent spectrum gives a triplet energy of -2.36eV. n-Doping with 8-hydroxyquinolatolithium (Liq, 1:1) leads to considerably improved electron mobility of 5.2 × 10 -6 -5.8 × 10 -5 cm2 v-1 S-1 at E=(2-5) × 10 5Vcm -1, in contrast with the triarylphosphine oxide- phenantroline molecular conjugate we reported previously. It has been shown that through optimizing the device structure and hence suppressing polaron-exciton annihilation, introducing this single Liq-doped electron-transport layer could offer high-efficiency and stable phosphorescent OLEDs.
基金supported primarily by the National Key Research and Development Program of China(2018YFA0209303)the National Natural Science Foundation of China(U1663228,51902153,51972165 and 61377051)the Fundamental Research Funds for the Central Universities of China。
文摘It is necessary to evaluate the interactions between the different functional layers in optoelectronic devices to optimize device performance.Recently,the I-rich allinorganic perovskite CsPbI2 Br has attracted tremendous attention for use in solar cell applications because of its suitable band gap and favorable photo and thermal stabilities.It has been reported that the undesirable phase degradation of the photoactiveαphase CsPbI2 Br to the non-perovskiteδphase could be triggered by high humidity.To obtain stable devices,it is thus important to protect CsPbI2 Br from moisture.In this paper,CuI,a non-hygroscopic p-type hole-transporting material,is found to induce the phase degradation ofα-CsPbI2 Br to theδ-CsPbI2 Br.The rate and extent of phase degradation of CsPbI2 Br are closely associated with the heating temperature and coverage of a Cu I granular capping layer.This discovery is different from the widely reported water-induced phase degradation of CsPbI2 Br.Our work highlights the importance of careful selection of hole-transporting materials during the processing of I-rich all-inorganic CsPbX3(X=Br,I)perovskites to realize high-performance optoelectronic devices.
基金supported by China Postdoctoral Science Foundation(2020M671242 and 2021T140688)the Special Research Assistant program of CASthe Super Postdoctoral Fellow Program of Shanghai。
文摘Rationally designed heterostructures provide attractive prospects for energy storage electrodes by combining different active materials with distinct electrochemical properties.Herein,through a phase separation strategy,a heterostructure of SnO_(2) encapsulated by amorphous Nb_(2)O_(5) is spontaneously synthesized.Insertion-type anode Nb_(2)O_(5) outer shell,playing as reaction containers and fast ionic pathways,physically inhibits the Sn atoms’migration and enhances the reaction kinetics.Moreover,strong chemical interactions are found at the SnO_(2)/Nb_(2)O_(5) interfaces,which ensure the solid encapsulation of the SnO_(2) cores even after 500 cycles.When used for lithium-ion batteries,this heterostructured anode exhibits high cycling stability with a capacity of 626 mAhg^(-1) after 1000 cycles at 2Ag^(-1)(85% capacity retention)and good rate performance with the capacity of 340 mAhg^(-1) at 8Ag^(-1).
基金supported by the Research Equipment Development Project of Chinese Academy of Sciences(Grant No.YZ201562)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.Y72014)+3 种基金the Program of Science and Technology Development Plan of Jilin Province of China(Grant No.20170519006JH)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB20000000)the National Natural Science Foundation of China(Grant Nos.21771172,21521092,21590794,21210001)the National Key Basic Research Program of China(Grant No.2014CB643802)
文摘In this work,efficient green electroluminescent(EL)devices with simplified device structure were prepared by doping trivalent terbium complex Tb(PMIP)3into hole block material Tm Py PB.The high triplet energy of Tm Py PB helps to confine excitons within light-emitting layer,while the electron transport characteristic of Tm Py PB facilitates the balance of carriers on Tb(PMIP)a3molecules.By optimizing the doping concentration of Tb(PMIP)a3and the thickness of each functional layer,highly efficient green EL device with the structure of ITO/Mo Oa3(3 nm)/TAPC(50 nm)/Tb(PMIP)a3(30 wt%):Tm Py PB(25 nm)/Tm Py PB(60 nm)/Li F(1 nm)/Al(100 nm)displayed pure Tb^3+ characteristic emission with maximum current efficiency,power efficiency and brightness up to 47.24 cd/A(external quantum efficiency(EQE)of 14.4%),43.63 lm/W and 1694 cd/m^2,respectively.At certain brightness of 100 cd/m^2,the device still maintained a current efficiency of 19.96 cd/A(EQE=6.1%).Such a device design strategy helps to improve the EL performances of Tb(PMIP)a3and to simplify device fabrication processes,thus reduce the fabrication cost.