Quasi-2D perovskites have attracted tremendous interest for application as lightemission layers in light-emitting diodes(LEDs).However,the heterogeneous n phase and non-uniform distribution still severely limit the fu...Quasi-2D perovskites have attracted tremendous interest for application as lightemission layers in light-emitting diodes(LEDs).However,the heterogeneous n phase and non-uniform distribution still severely limit the further development of quasi-2D perovskite LEDs(Pero-LEDs).Meanwhile,the increased defect density caused by the reduced dimension and grain size induces non-radiative recombination and further deteriorates the device performance.Here,we found that a series of molecules containing phosphoryl chloride functional groups have noticeable enhancement effects on the device performance of quasi-2D Pero-LEDs.Then,we studied the modification mechanism by focusing on the bis(2-oxo-3-oxazolidinyl)phosphinic chloride(BOPCl).It is concluded that the BOPCl can not only regulate the phase distribution by decreasing the crystallization rate but also remain in the grain boundaries and passivate the defects.As a result,the corresponding quasi-2D Pero-LEDs obtained a maximum external quantum efficiency(EQE_(max))of 20.82%and an average EQE(EQE_(ave))of around 20%on the optimal 50 devices,proving excellent reproducibility.Our work provides a new selection of molecular types for regulating the crystallization and passivating the defects of quasi-2D perovskite films.展开更多
Lead-free inorganic copper-silver-bismuth-halide materials have attracted more and more attention due to their environmental friendliness,high element abundance,and low cost.Here,we developed a strategy of one-step ga...Lead-free inorganic copper-silver-bismuth-halide materials have attracted more and more attention due to their environmental friendliness,high element abundance,and low cost.Here,we developed a strategy of one-step gas-solid-phase diffusioninduced reaction to fabricate a series of bandgap-tunable Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI bilayer films due to the atomic diffusion effect for the first time.By designing and regulating the sputtered Cu/Ag/Bi metal film thickness,the bandgap of Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI could be reduced from 2.06 to 1.78 eV.Solar cells with the structure of FTO/TiO_(2)/Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI/carbon were constructed,yielding a champion power conversion efficiency of 2.76%,which is the highest reported for this class of materials owing to the bandgap reduction and the peculiar bilayer structure.The current work provides a practical path for developing the next generation of efficient,stable,and environmentally friendly photovoltaic materials.展开更多
Due to isothermal heat treatment or welding,duplex stainless undergoes a variety of decomposition processes at a temperature ranging from 300 - 1 100℃,which could form inter-metallic phases likeσ-phase and xphase,as...Due to isothermal heat treatment or welding,duplex stainless undergoes a variety of decomposition processes at a temperature ranging from 300 - 1 100℃,which could form inter-metallic phases likeσ-phase and xphase,as well as Cr_2N and M_(23)C_6,etc.These processes are not only influenced by temperature and cooling speed, but also are affected by alloy element content.The purpose of the research was to work out the qualitative and quantitative analysis of precipitate phases in 2 205 duplex stainless steel with different isothermal heat treatment situation.After choosing the electrolyte and electrolytic systems,we use electrochemical method to extract precipitate phases from the matrix.Scanning electron microscope(SEM) and X-ray diffraction(XRD) were used to examine their modality and structure.Particle size distribution was performed by dynamic laser scattering sizer (DLS-Sizer).Furthermore,oxygen-nitrogen analyzer and carbon-sulfur analyzer were applied to measure the content of nitrogen and carbon in precipitate phases.Separation and quantitative analysis of precipitate phases were carried out by wet chemical analysis and inductively coupled plasma spectrometry(ICP).In a word,combining chemical and physical methods,our research reveals the transformation of precipitate phases'species,content, elemental composition and particle size distribution during different isothermal heat treatment situation.展开更多
Characteristics of the precipitate α″-Fe16N2 phase have been investigated by X-ray diffraction and TEM analysis. VSM measurements give the saturation magnetization of the α″ phase.
The solid–liquid equilibria(SLE)for binary and ternary systems consisting of N-Vinylpyrrolidone(NVP),2-Pyrrolidone(2-P)and water are measured.The phase diagrams of NVP(1)+2-P(2),NVP(1)+water(2),NVP(1)+2-P(2)+1 wt%wat...The solid–liquid equilibria(SLE)for binary and ternary systems consisting of N-Vinylpyrrolidone(NVP),2-Pyrrolidone(2-P)and water are measured.The phase diagrams of NVP(1)+2-P(2),NVP(1)+water(2),NVP(1)+2-P(2)+1 wt%water(3)and NVP(1)+2-P(2)+2 wt%water(3)are identified as simple eutectic type with the eutectic points at 263.75 K(x_(1E)=0.5427),251.65 K(x_(1E)=0.3722),260.25 K(x_(1E)=0.5031)and256.55 K(x_(1E)=0.4684),respectively.The phase diagram of 2-P(1)+water(2)has two eutectic points(x_(1E)=0.1236,T_E=259.15 K and x_(1E)=0.7831,T_E=286.15 K)and one congruent melting point(x_(1C)=0.4997,T_C=303.55 K)because of the generation of a congruently melting addition compound:2-P·H_2O.The ideal solubility and the UNIFAC models were applied to predict the SLE,while the Wilson and NRTL models were employed in correlating the experimental data.The best correlation of the SLE data has been obtained by the Wilson model for the binary system of NVP+2-P.The UNIFAC model gives more satisfactory predictions than the ideal solubility model.展开更多
基金supported by the National Natural Science Foundation of China(U21A2078)Natural Science Foundation of Fujian Province(2020J06021,2019J01057,and 2020J01064)Scientific Research Funds of Huaqiao University.
文摘Quasi-2D perovskites have attracted tremendous interest for application as lightemission layers in light-emitting diodes(LEDs).However,the heterogeneous n phase and non-uniform distribution still severely limit the further development of quasi-2D perovskite LEDs(Pero-LEDs).Meanwhile,the increased defect density caused by the reduced dimension and grain size induces non-radiative recombination and further deteriorates the device performance.Here,we found that a series of molecules containing phosphoryl chloride functional groups have noticeable enhancement effects on the device performance of quasi-2D Pero-LEDs.Then,we studied the modification mechanism by focusing on the bis(2-oxo-3-oxazolidinyl)phosphinic chloride(BOPCl).It is concluded that the BOPCl can not only regulate the phase distribution by decreasing the crystallization rate but also remain in the grain boundaries and passivate the defects.As a result,the corresponding quasi-2D Pero-LEDs obtained a maximum external quantum efficiency(EQE_(max))of 20.82%and an average EQE(EQE_(ave))of around 20%on the optimal 50 devices,proving excellent reproducibility.Our work provides a new selection of molecular types for regulating the crystallization and passivating the defects of quasi-2D perovskite films.
基金supported by National Natural Science Foundation of China(Grant No.52072327,62074052,61874159)Zhongyuan Thousand Talents(Zhongyuan Scholars)Program of Henan Province(202101510004)+6 种基金Higher Education and Teaching Reformation Project(2014SJGLX064)Academic Degrees&Graduate Education Reform Project of Henan Province(2021SJGLX060Y)Key research and development projects of Universities in Henan Province(20A140026)the Scientific Research Innovation Team of Xuchang University(2022CXTD008)Science and Technology Project of Henan Province(222102230009).L.Ding thanks the National Key Research and Development Program of China(2022YFB3803300)the open research fund of Songshan Lake Materials Laboratory(2021SLABFK02)the National Natural Science Foundation of China(21961160720).
文摘Lead-free inorganic copper-silver-bismuth-halide materials have attracted more and more attention due to their environmental friendliness,high element abundance,and low cost.Here,we developed a strategy of one-step gas-solid-phase diffusioninduced reaction to fabricate a series of bandgap-tunable Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI bilayer films due to the atomic diffusion effect for the first time.By designing and regulating the sputtered Cu/Ag/Bi metal film thickness,the bandgap of Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI could be reduced from 2.06 to 1.78 eV.Solar cells with the structure of FTO/TiO_(2)/Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI/carbon were constructed,yielding a champion power conversion efficiency of 2.76%,which is the highest reported for this class of materials owing to the bandgap reduction and the peculiar bilayer structure.The current work provides a practical path for developing the next generation of efficient,stable,and environmentally friendly photovoltaic materials.
文摘Due to isothermal heat treatment or welding,duplex stainless undergoes a variety of decomposition processes at a temperature ranging from 300 - 1 100℃,which could form inter-metallic phases likeσ-phase and xphase,as well as Cr_2N and M_(23)C_6,etc.These processes are not only influenced by temperature and cooling speed, but also are affected by alloy element content.The purpose of the research was to work out the qualitative and quantitative analysis of precipitate phases in 2 205 duplex stainless steel with different isothermal heat treatment situation.After choosing the electrolyte and electrolytic systems,we use electrochemical method to extract precipitate phases from the matrix.Scanning electron microscope(SEM) and X-ray diffraction(XRD) were used to examine their modality and structure.Particle size distribution was performed by dynamic laser scattering sizer (DLS-Sizer).Furthermore,oxygen-nitrogen analyzer and carbon-sulfur analyzer were applied to measure the content of nitrogen and carbon in precipitate phases.Separation and quantitative analysis of precipitate phases were carried out by wet chemical analysis and inductively coupled plasma spectrometry(ICP).In a word,combining chemical and physical methods,our research reveals the transformation of precipitate phases'species,content, elemental composition and particle size distribution during different isothermal heat treatment situation.
文摘Characteristics of the precipitate α″-Fe16N2 phase have been investigated by X-ray diffraction and TEM analysis. VSM measurements give the saturation magnetization of the α″ phase.
文摘The solid–liquid equilibria(SLE)for binary and ternary systems consisting of N-Vinylpyrrolidone(NVP),2-Pyrrolidone(2-P)and water are measured.The phase diagrams of NVP(1)+2-P(2),NVP(1)+water(2),NVP(1)+2-P(2)+1 wt%water(3)and NVP(1)+2-P(2)+2 wt%water(3)are identified as simple eutectic type with the eutectic points at 263.75 K(x_(1E)=0.5427),251.65 K(x_(1E)=0.3722),260.25 K(x_(1E)=0.5031)and256.55 K(x_(1E)=0.4684),respectively.The phase diagram of 2-P(1)+water(2)has two eutectic points(x_(1E)=0.1236,T_E=259.15 K and x_(1E)=0.7831,T_E=286.15 K)and one congruent melting point(x_(1C)=0.4997,T_C=303.55 K)because of the generation of a congruently melting addition compound:2-P·H_2O.The ideal solubility and the UNIFAC models were applied to predict the SLE,while the Wilson and NRTL models were employed in correlating the experimental data.The best correlation of the SLE data has been obtained by the Wilson model for the binary system of NVP+2-P.The UNIFAC model gives more satisfactory predictions than the ideal solubility model.
