Middle-sized chambers (40cmx40cmx20 cm) and an infrared gas analyzer (IRGA) were used for the measurement of net photosynthesis of the grass layer and soil CO2 evolution, in Quercus liaotungensis Koidz. forest, which ...Middle-sized chambers (40cmx40cmx20 cm) and an infrared gas analyzer (IRGA) were used for the measurement of net photosynthesis of the grass layer and soil CO2 evolution, in Quercus liaotungensis Koidz. forest, which is a typical temperate forest ecosystem in the mountainous areas of Beijing. Changes of CO2 concentrations in both the atmosphere (2m above canopy) and the forest canopy (2m below the top of the canopy) together with those of net photosynthesis and soil CO2 evolution were also examined, in order to find the characteristics of CO2 exchange between the different components of the temperate forest ecosystem and the atmosphere. Atmospheric CO2 averaged (323+10) and (330+1) mol mol-1 respectively in summer and autumn. During the 24-hour measurements, large differences as much as -46 and -61 mol mol-1 respectively in the atmosphere and forest were found. Net photosynthesis of the grass layer in summer was (2. 59 9+ 1.05) mol CO2 m-2 S-1, two times of that in autumn, (1.31+0.39) mol CO2 s-1 In summer, there was much more CO2 evolved from soil than in autumn, averaging (5.18+0.75) mol CO2 m-2 s-1 and (1.96 + 0.57) (mol CO2 m-2 s-1, respectively. A significant correlation was found between soil CO2 evolution and ground temperature, with F =-0.864 2+0.310 1X,r=0.7164, P<0.001 (n=117). Both the minimal atmospheric CO2 level and the maximum net photosynthesis occurred around 14:00; and an increase in atmospheric CO2 and of soil CO2 evolution during night times were also found to be remarkable.展开更多
The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, ...The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, etc. were identified. The analysis revealed that the diurnal rhythm of release of volatile compounds from maple differed in July and in August. In July, the releasing of most volatile compounds reached the peak at 14 o'clock, when in August, the emission of volatile compounds reached the peak at 10 o'clock. Besides diurnal rhythm, there also existed other differences in the releasing of volatiles and their relative contents in July and in August. A possible explanation for this phenomenon is the maturation of leaves, since the sampling conditions were the same both in July and August. At the same time, the response of Anoplophora glabrpennis Motschulsky to volatiles was examined with field bioassay with traps. cis-3-hexen-1-ol was found to be more effective to attract A. glabrpennis than other volatiles released by ash-leaf maple tree in field trapping test. A mixture of 1-butanol, 1-pentanol and 2-pentanol was tested to be the most attractive to A. glabripennis among all tested volatiles. More field trapping tests should be conducted.展开更多
The photodissociation dynamics of m-brornofluorobenzene has been experimentally investi- gated at around 240 nrn using the DC-slice velocity map imaging technique. The kinetic energy release spectra and the recoiling ...The photodissociation dynamics of m-brornofluorobenzene has been experimentally investi- gated at around 240 nrn using the DC-slice velocity map imaging technique. The kinetic energy release spectra and the recoiling angular distributions of fragmented Br（2P3/2） and Br（2P1/2） atoms from photodissociation of m-bromofluorobenzene have been measured at diff）rent photolysis wavelengths around 240 nm. The experimental results indicate that two dissociation pathways via （pre-）dissociation of the two low-lying 1ππ excited states dominate the production process of the ground state Br（2P3/2） atoms. Because of the weak spin-orbit coupling eff）ct among the low-lying triplet and singlet states, the spin-orbit excited Br（2P1/2） atoms are mainly produced via singlet-triplet state coupling in the dissociation step. The similarity between the present results and that recently reported for o-bromofluorobenzene indicates that the substitution position of the fluorine atom does not significantly affect the UV photodissociation dynamics of bromofluorobenzenes.展开更多
Stable sub 500 nm bovine serum albumin (BSA) microsphere suspensions were produced by controlled addition of acetone and ethanol to an aqueous solution of BSA, followed by stabilization process of the formed microsphe...Stable sub 500 nm bovine serum albumin (BSA) microsphere suspensions were produced by controlled addition of acetone and ethanol to an aqueous solution of BSA, followed by stabilization process of the formed microspheres at an elevated temperature. Microspheres produced by this acetone ethanol heat denaturation method were stabilized at relatively low temperatures (70～75℃) over a short period of time (20 min). The acetone ethanol heat denaturation method, in comparison with the traditional oil/ water technique for preparation of albumin microspheres, which requires high temperature (over 100℃) and longer heating time (more than 30 min) for stabilization, offers a number of advantages. This report describes the influence of process conditions, such as ratios of acetone to ethanol to BSA aqueous solution, heating time and heating temperature, on microsphere formation and their stability. A loading efficiency of 40% rose bengal was achieved. Rose bengal release rates from these microspheres in phosphate buffered saline medium at 37 ℃ were dependent on microsphere stabilities and 25% to 60% of initial loading drug were released in 15 days.展开更多
Chemical doping is an effective method to intrinsically modify the chemical and electronic property of graphene. We propose a novel approach to synthesize the nitrogen-doped graphene via thermal annealing graphene wit...Chemical doping is an effective method to intrinsically modify the chemical and electronic property of graphene. We propose a novel approach to synthesize the nitrogen-doped graphene via thermal annealing graphene with urea, in which the nitrogen source can be controllably released from the urea by varying the annealed temperature and time. The doped N content and the configuration N as well as the thermal stabilities are also evaluated with X-ray photoelectron spectroscopy and Raman spectra. Electrical measurements indi- cate that the conductivity of doped graphene can be well regulated with the N content. The method is expected to produce large scale and controllable N-doped graphene sheets for a variety of potential applications.展开更多
It is investigated to synthesis of Ag nanoparticles by presence the synthetic polymer poly-N-vinylpyrrolidone. It was determined with X-ray analyses that the size ofnanoparticles changed between 18-42 nm. Then, the au...It is investigated to synthesis of Ag nanoparticles by presence the synthetic polymer poly-N-vinylpyrrolidone. It was determined with X-ray analyses that the size ofnanoparticles changed between 18-42 nm. Then, the authors studied sorption process of doxorubicine by silver nanocomposites and investigated chemical interaction between antibiotic and poly-N-vinyplyrrolidone with UV-VIS （ultraviolet visible） and FT-IR （Fourier transform infrared） spectroscopy. It is shown that formation of the nanoparticles doxorubicin complex mainly occurs in the 190-208 nm wavelengths on polymers 〉C=O functional groups. Also, the four main absorbing peaks of doxorubicin--234, 253, 288 and 495 nm undergo chemists shift （A2 = 12-15 nm）. When increases to pH = 7-8, the size of Ag-doxorubicin particles decreases. It is determined that the 410 nm absorption peak of Ag nanoparticles undergo 409-418 nm interval and the 3,500, 1,600, 1,645 and 1,190 sm^-1 absorption lines of PVPr （polymer poly-N-vinylpyrrolidone） slightly altered.展开更多
The photodissociation dynamics of acetaldehyde in the radical channel CH3＋HCO has been reinvestigated using time-sliced velocity map imaging technique in the photolysis wavelength range of 275-321 nm. The CH3 fragmen...The photodissociation dynamics of acetaldehyde in the radical channel CH3＋HCO has been reinvestigated using time-sliced velocity map imaging technique in the photolysis wavelength range of 275-321 nm. The CH3 fragments have been probed via （2＋1） resonance-enhanced multiphoton ionization. Images are measured for CH3 formed in the ground and excited states （v2=0 and 1） of the umbrella vibrational mode. For acetaldehyde dissociation on T1 state after intersystem crossing from S1 state, the products are formed with high translational energy release and low internal excitation. The rotational and vibrational energy of both fragments increases with increasing photodissociation energy. The triplet barrier height is estimated at 3.8814-0.006 eV above the ground state of acetaldehyde.展开更多
Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate...Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate the skin dose calculation accuracy of the XIO 4.04 treatment planning system. Methods: More investigations for the influences of IMRT on skin doses would increase its applications for many treatment sites. Measuring skin doses in real treatment situations would reduce the uncertainty of skin dose prediction. In this work a pediatric human phantom was covered by a layer of 1 mm bolus at three treatment sites and thermoluminescent dosimeter (TLD) chips were inserted into the bolus at each treatment site before CT scan. Two different treatment plans [three-dimensional conformal radiation therapy (3DCRT) and IMRT] for each treatment sites were performed on XIO 4.04 treatment planning system using superposition algorism. Results: The results showed that the surface doses for 3DCRT were higher than the surface doses in IMRT by 1.6%, 2.5% and 3.2% for brain, abdomen and pelvis sites respectively. There was good agreement between measured and calculated surface doses, where the calculated surface dose was 15.5% for brain tumor calculated with 3DCRT whereas the measured surface dose was 12.1%. For abdomen site the calculated surface dose for IMRT treatment plan was 16.5% whereas the measured surface dose was 12.6%. Conclusion: The skin dose in IMRT for deep seated tumors is lower than that in 3DCRT which is another advantage for the IMRT. The TLD readings showed that the difference between the calculated and measured point dose is negligible. The superposition calculation algorism of the XIO 4.04 treatment planning system modeled the superficial dose well.展开更多
Serious fouling and slagging problems are associated with the combustion of Chinese Zhun-Dong coal due to its high content of sodium （Na）. Understanding the release characteristic of Na during the combustion is esse...Serious fouling and slagging problems are associated with the combustion of Chinese Zhun-Dong coal due to its high content of sodium （Na）. Understanding the release characteristic of Na during the combustion is essential to viable utilization of this coal. In this work, coal samples were treated with a sequence of solvents： water （H2O）, ammonium acetate （NH4Ac）, hydrochloric acid （HC1）, and the release characteristics of various classes of Na during coal combustion were investigated using the technique of laser-induced breakdown spectroscopy. The relative contribution of various Na classes to the Na release during each combustion stage was found to be similar, in the order of H2O-soluble Na 〉 NHaAcsoluble Na 〉 HCl-soluble Na 〉 insoluble Na. Sodium released during the devolatilization stage can be attributed to each of the sodium classes. After the devolatilization stage, H2O-soluble Na and NHaAc-soluble Na dominated the Na release during both char and ash stages. Over 64 % of the total Na released during combustion comes from the H2O-soluble Na, which suggests that the Na release during the combustion of Zhun-Dong coal can be reduced effectively after treatment by H2O washing.展开更多
Thermosensitive drug delivery systems （DDSs） face major challenges, such as remote and repeatable control of in vivo temperature, although these can increase the therapeutic efficacy of drugs. To address this issue,...Thermosensitive drug delivery systems （DDSs） face major challenges, such as remote and repeatable control of in vivo temperature, although these can increase the therapeutic efficacy of drugs. To address this issue, we coated near- infrared （NIR） photothermal Cu175S nanocrystals with pH/thermos-sensitive polymer by in situ polymerization. The doxorubicine （DOX） loading content was up to 40 wt.%, with less than 8.2 wt.% of DOX being leaked under normal physiological conditions （pH = 7.4, 37 ~C） for almost 48 h in the absence of NIR light. These nanocapsules demonstrate excellent photothermal stability by continuous long- term NIR irradiation. Based on the stable and high photothermal efficiency （55.8%）, pre-loaded drugs were released as desired using 808-nm light as a trigger. Both in vitro and in vivo antitumor therapy results demonstrated that this smart nanoplatform is an effective agent for synergistic hyperthermia-based chemotherapy of cancer, demonstratin~ remote and noninvasive control.展开更多
Hydrothermal deposition of antimony selenosulfide(Sb_(2)(S,Se_(3)))has enabled solar cell applications to surpass the 10%efficiency threshold.This deposition process involves the reaction of three precursor materials:...Hydrothermal deposition of antimony selenosulfide(Sb_(2)(S,Se_(3)))has enabled solar cell applications to surpass the 10%efficiency threshold.This deposition process involves the reaction of three precursor materials:Sb,S,and Se.However,this process generates an unfavourable gradient of Se and S anions in the Sb_(2)(S,Se)_(3)film,which limits further efficiency improvements.Herein,we demonstrate how NH_(4)F can be used as an additive to regulate the band gradient of the Sb_(2)(S,Se)_(3)and modify the surface of the CdS electron-transporting layer.On the one hand,NH_(4)F inhibits the decomposition of Na_(2)S_(2)O_(3)and selenourea,which optimizes the deposition process and allows for adjustment of the Se/S ratio and their distribution in the Sb_(2)(S,Se)_(3)film.On the other hand,hydrolysis of NH_(4)F induces dissolution and redeposition of CdS,thereby effectively improving the morphology and crystallinity of the CdS substrate.Finally,the dual effect of NH_(4)F enables improved surface morphology and energy alignment of the Sb_(2)(S,Se)_(3)film,thus yielding a maximum efficiency of 10.28%,a 12%improvement over the control device.This study demonstrates an effective strategy for simultaneously modifying a sulfide-based substrate and regulating the element distribution during the deposition of a metal chalcogenide film for optoelectronic device applications.展开更多
基金This is a key project of National Natural Science Foundation of China.
文摘Middle-sized chambers (40cmx40cmx20 cm) and an infrared gas analyzer (IRGA) were used for the measurement of net photosynthesis of the grass layer and soil CO2 evolution, in Quercus liaotungensis Koidz. forest, which is a typical temperate forest ecosystem in the mountainous areas of Beijing. Changes of CO2 concentrations in both the atmosphere (2m above canopy) and the forest canopy (2m below the top of the canopy) together with those of net photosynthesis and soil CO2 evolution were also examined, in order to find the characteristics of CO2 exchange between the different components of the temperate forest ecosystem and the atmosphere. Atmospheric CO2 averaged (323+10) and (330+1) mol mol-1 respectively in summer and autumn. During the 24-hour measurements, large differences as much as -46 and -61 mol mol-1 respectively in the atmosphere and forest were found. Net photosynthesis of the grass layer in summer was (2. 59 9+ 1.05) mol CO2 m-2 S-1, two times of that in autumn, (1.31+0.39) mol CO2 s-1 In summer, there was much more CO2 evolved from soil than in autumn, averaging (5.18+0.75) mol CO2 m-2 s-1 and (1.96 + 0.57) (mol CO2 m-2 s-1, respectively. A significant correlation was found between soil CO2 evolution and ground temperature, with F =-0.864 2+0.310 1X,r=0.7164, P<0.001 (n=117). Both the minimal atmospheric CO2 level and the maximum net photosynthesis occurred around 14:00; and an increase in atmospheric CO2 and of soil CO2 evolution during night times were also found to be remarkable.
文摘The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, etc. were identified. The analysis revealed that the diurnal rhythm of release of volatile compounds from maple differed in July and in August. In July, the releasing of most volatile compounds reached the peak at 14 o'clock, when in August, the emission of volatile compounds reached the peak at 10 o'clock. Besides diurnal rhythm, there also existed other differences in the releasing of volatiles and their relative contents in July and in August. A possible explanation for this phenomenon is the maturation of leaves, since the sampling conditions were the same both in July and August. At the same time, the response of Anoplophora glabrpennis Motschulsky to volatiles was examined with field bioassay with traps. cis-3-hexen-1-ol was found to be more effective to attract A. glabrpennis than other volatiles released by ash-leaf maple tree in field trapping test. A mixture of 1-butanol, 1-pentanol and 2-pentanol was tested to be the most attractive to A. glabripennis among all tested volatiles. More field trapping tests should be conducted.
基金financially supported by the National Key R&D Program of China(2017YFA0303502)the National Natural Science Foundation of China(No.21773221 and No.21727804)the Fundamental Research Funds for the Central Universities of China
文摘The photodissociation dynamics of m-brornofluorobenzene has been experimentally investi- gated at around 240 nrn using the DC-slice velocity map imaging technique. The kinetic energy release spectra and the recoiling angular distributions of fragmented Br（2P3/2） and Br（2P1/2） atoms from photodissociation of m-bromofluorobenzene have been measured at diff）rent photolysis wavelengths around 240 nm. The experimental results indicate that two dissociation pathways via （pre-）dissociation of the two low-lying 1ππ excited states dominate the production process of the ground state Br（2P3/2） atoms. Because of the weak spin-orbit coupling eff）ct among the low-lying triplet and singlet states, the spin-orbit excited Br（2P1/2） atoms are mainly produced via singlet-triplet state coupling in the dissociation step. The similarity between the present results and that recently reported for o-bromofluorobenzene indicates that the substitution position of the fluorine atom does not significantly affect the UV photodissociation dynamics of bromofluorobenzenes.
文摘Stable sub 500 nm bovine serum albumin (BSA) microsphere suspensions were produced by controlled addition of acetone and ethanol to an aqueous solution of BSA, followed by stabilization process of the formed microspheres at an elevated temperature. Microspheres produced by this acetone ethanol heat denaturation method were stabilized at relatively low temperatures (70～75℃) over a short period of time (20 min). The acetone ethanol heat denaturation method, in comparison with the traditional oil/ water technique for preparation of albumin microspheres, which requires high temperature (over 100℃) and longer heating time (more than 30 min) for stabilization, offers a number of advantages. This report describes the influence of process conditions, such as ratios of acetone to ethanol to BSA aqueous solution, heating time and heating temperature, on microsphere formation and their stability. A loading efficiency of 40% rose bengal was achieved. Rose bengal release rates from these microspheres in phosphate buffered saline medium at 37 ℃ were dependent on microsphere stabilities and 25% to 60% of initial loading drug were released in 15 days.
文摘Chemical doping is an effective method to intrinsically modify the chemical and electronic property of graphene. We propose a novel approach to synthesize the nitrogen-doped graphene via thermal annealing graphene with urea, in which the nitrogen source can be controllably released from the urea by varying the annealed temperature and time. The doped N content and the configuration N as well as the thermal stabilities are also evaluated with X-ray photoelectron spectroscopy and Raman spectra. Electrical measurements indi- cate that the conductivity of doped graphene can be well regulated with the N content. The method is expected to produce large scale and controllable N-doped graphene sheets for a variety of potential applications.
文摘It is investigated to synthesis of Ag nanoparticles by presence the synthetic polymer poly-N-vinylpyrrolidone. It was determined with X-ray analyses that the size ofnanoparticles changed between 18-42 nm. Then, the authors studied sorption process of doxorubicine by silver nanocomposites and investigated chemical interaction between antibiotic and poly-N-vinyplyrrolidone with UV-VIS （ultraviolet visible） and FT-IR （Fourier transform infrared） spectroscopy. It is shown that formation of the nanoparticles doxorubicin complex mainly occurs in the 190-208 nm wavelengths on polymers 〉C=O functional groups. Also, the four main absorbing peaks of doxorubicin--234, 253, 288 and 495 nm undergo chemists shift （A2 = 12-15 nm）. When increases to pH = 7-8, the size of Ag-doxorubicin particles decreases. It is determined that the 410 nm absorption peak of Ag nanoparticles undergo 409-418 nm interval and the 3,500, 1,600, 1,645 and 1,190 sm^-1 absorption lines of PVPr （polymer poly-N-vinylpyrrolidone） slightly altered.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.21203186 and No.21073187）, the National Key Basic Research Program of China （No.2010CB923302）, 100 Talents Program of Chinese Academy of Sciences, and Knowledge Innovation Program of Chinese Academy of Sciences.
文摘The photodissociation dynamics of acetaldehyde in the radical channel CH3＋HCO has been reinvestigated using time-sliced velocity map imaging technique in the photolysis wavelength range of 275-321 nm. The CH3 fragments have been probed via （2＋1） resonance-enhanced multiphoton ionization. Images are measured for CH3 formed in the ground and excited states （v2=0 and 1） of the umbrella vibrational mode. For acetaldehyde dissociation on T1 state after intersystem crossing from S1 state, the products are formed with high translational energy release and low internal excitation. The rotational and vibrational energy of both fragments increases with increasing photodissociation energy. The triplet barrier height is estimated at 3.8814-0.006 eV above the ground state of acetaldehyde.
文摘Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate the skin dose calculation accuracy of the XIO 4.04 treatment planning system. Methods: More investigations for the influences of IMRT on skin doses would increase its applications for many treatment sites. Measuring skin doses in real treatment situations would reduce the uncertainty of skin dose prediction. In this work a pediatric human phantom was covered by a layer of 1 mm bolus at three treatment sites and thermoluminescent dosimeter (TLD) chips were inserted into the bolus at each treatment site before CT scan. Two different treatment plans [three-dimensional conformal radiation therapy (3DCRT) and IMRT] for each treatment sites were performed on XIO 4.04 treatment planning system using superposition algorism. Results: The results showed that the surface doses for 3DCRT were higher than the surface doses in IMRT by 1.6%, 2.5% and 3.2% for brain, abdomen and pelvis sites respectively. There was good agreement between measured and calculated surface doses, where the calculated surface dose was 15.5% for brain tumor calculated with 3DCRT whereas the measured surface dose was 12.1%. For abdomen site the calculated surface dose for IMRT treatment plan was 16.5% whereas the measured surface dose was 12.6%. Conclusion: The skin dose in IMRT for deep seated tumors is lower than that in 3DCRT which is another advantage for the IMRT. The TLD readings showed that the difference between the calculated and measured point dose is negligible. The superposition calculation algorism of the XIO 4.04 treatment planning system modeled the superficial dose well.
基金supported by the National Natural Science Foundation of China(51406178)China Postdoctoral Science Foundation(2014M551732)+1 种基金National Basic Research Program of China(2012CB214906)Specialized Research Fund for the Doctoral Program of Higher Education of China(20130101110095)
文摘Serious fouling and slagging problems are associated with the combustion of Chinese Zhun-Dong coal due to its high content of sodium （Na）. Understanding the release characteristic of Na during the combustion is essential to viable utilization of this coal. In this work, coal samples were treated with a sequence of solvents： water （H2O）, ammonium acetate （NH4Ac）, hydrochloric acid （HC1）, and the release characteristics of various classes of Na during coal combustion were investigated using the technique of laser-induced breakdown spectroscopy. The relative contribution of various Na classes to the Na release during each combustion stage was found to be similar, in the order of H2O-soluble Na 〉 NHaAcsoluble Na 〉 HCl-soluble Na 〉 insoluble Na. Sodium released during the devolatilization stage can be attributed to each of the sodium classes. After the devolatilization stage, H2O-soluble Na and NHaAc-soluble Na dominated the Na release during both char and ash stages. Over 64 % of the total Na released during combustion comes from the H2O-soluble Na, which suggests that the Na release during the combustion of Zhun-Dong coal can be reduced effectively after treatment by H2O washing.
文摘Thermosensitive drug delivery systems （DDSs） face major challenges, such as remote and repeatable control of in vivo temperature, although these can increase the therapeutic efficacy of drugs. To address this issue, we coated near- infrared （NIR） photothermal Cu175S nanocrystals with pH/thermos-sensitive polymer by in situ polymerization. The doxorubicine （DOX） loading content was up to 40 wt.%, with less than 8.2 wt.% of DOX being leaked under normal physiological conditions （pH = 7.4, 37 ~C） for almost 48 h in the absence of NIR light. These nanocapsules demonstrate excellent photothermal stability by continuous long- term NIR irradiation. Based on the stable and high photothermal efficiency （55.8%）, pre-loaded drugs were released as desired using 808-nm light as a trigger. Both in vitro and in vivo antitumor therapy results demonstrated that this smart nanoplatform is an effective agent for synergistic hyperthermia-based chemotherapy of cancer, demonstratin~ remote and noninvasive control.
基金the National Natural Science Foundation of China(22005293 and U19A2092)the National Key Research and Development Program of China(2019YFA0405600).
文摘Hydrothermal deposition of antimony selenosulfide(Sb_(2)(S,Se_(3)))has enabled solar cell applications to surpass the 10%efficiency threshold.This deposition process involves the reaction of three precursor materials:Sb,S,and Se.However,this process generates an unfavourable gradient of Se and S anions in the Sb_(2)(S,Se)_(3)film,which limits further efficiency improvements.Herein,we demonstrate how NH_(4)F can be used as an additive to regulate the band gradient of the Sb_(2)(S,Se)_(3)and modify the surface of the CdS electron-transporting layer.On the one hand,NH_(4)F inhibits the decomposition of Na_(2)S_(2)O_(3)and selenourea,which optimizes the deposition process and allows for adjustment of the Se/S ratio and their distribution in the Sb_(2)(S,Se)_(3)film.On the other hand,hydrolysis of NH_(4)F induces dissolution and redeposition of CdS,thereby effectively improving the morphology and crystallinity of the CdS substrate.Finally,the dual effect of NH_(4)F enables improved surface morphology and energy alignment of the Sb_(2)(S,Se)_(3)film,thus yielding a maximum efficiency of 10.28%,a 12%improvement over the control device.This study demonstrates an effective strategy for simultaneously modifying a sulfide-based substrate and regulating the element distribution during the deposition of a metal chalcogenide film for optoelectronic device applications.
