In this work,uniform reduced graphene oxide（RGO） films were formed on poly-（ethylene terephthalate）（PET） substrates using a simple drop-casting method.We investigated four types of substrates：unmodified PET,pol...In this work,uniform reduced graphene oxide（RGO） films were formed on poly-（ethylene terephthalate）（PET） substrates using a simple drop-casting method.We investigated four types of substrates：unmodified PET,polydopamine-coated PET.carboxyl-group-modified PET,and alkyl-group-modified PET.Upon water evaporation,the surface of the polydopamine-modified PET substrates can interact with the reduced graphene oxide sheets to form flattened and continuous RGO films,which exhibit a sheet resistance of 21.75 kΩ/sq at 82% transmittance.The result indicates that the properties of the surface groups determined whether uniform and flattened RGO films could be formed on the substrates.Hence,we proposed a simple and effective way to produce transparent and conductive films in which the catechol unit exhibits a great effect on the deposition of uniform RGO films on PET substrates.展开更多
Due to the exciting photoelectric properties,better stability,and environmental-friendly nature,all-inorganic halide perovskites(AIHPs),especially the lead-free perovskites,have attracted worldwide attention.However,t...Due to the exciting photoelectric properties,better stability,and environmental-friendly nature,all-inorganic halide perovskites(AIHPs),especially the lead-free perovskites,have attracted worldwide attention.However,the film quality of AIHPs fabricated by typical spin-coating and subsequent high-temperature annealing is still not satisfactory,restricting their further development.Herein,we demonstrate a simple low-temperature solution-processed drop-casting method to achieve highly-crystalline cubic CsPbBr_(3)and lead-free layer-structured Cs_(3)Sb_(2)I_(9)microcrystals(MCs).This drop-casting technique not only consumes the less amount of precursor solution but also eliminates the high-temperature annealing as compared with those of spin coating.When these MCs are configured into photodetectors,they exhibit superior device performance,which is in distinct contrast to the one of spin-coated counterparts.Specifically,the responsivity of CsPbBr_(3)MCs is found to be as large as 8,990 mA/W,being 13 times larger than the spin-coated films and even better than many state-of-the-art solution-processed AIHPs devices.This device performance enhancement is attributed to the better film quality and phase purity obtained by the drop-casting method.All these results can evidently fill the“technology gap”for further enhancing the material quality of solution-processed AIHPs and breaking down the barriers that hinder the development of AIHPs based optoelectronic devices.展开更多
Tin oxide (SnO<sub>2</sub>) thin films were deposited on glass substrate by Chemical Bath Deposition (CBD), Drop-Cast and Dip-Coating method. The thin films were post-annealed at 500°C for 2 hours....Tin oxide (SnO<sub>2</sub>) thin films were deposited on glass substrate by Chemical Bath Deposition (CBD), Drop-Cast and Dip-Coating method. The thin films were post-annealed at 500°C for 2 hours. The structural, optical, and electrical properties of the SnO<sub>2</sub> thin films were investigated by using XRD, FTIR, SEM, EDX, UV-Vis spectroscopy, and Electrometer experiment. The XRD patterns of SnO<sub>2</sub> thin films deposited on glass substrate by CBD method, Drop-Cast method and Dip-Coating method showed cubic, tetragonal and amorphous structures respectively. The FTIR spectrum exhibited the strong presence of SnO<sub>2</sub> with the characteristic vibrational mode of Sn-O-Sn. The SEM analysis was observed that the surface morphology of the thin films toughly depends on the deposition methods of the SnO<sub>2</sub> thin films. EDX measurement confirmed that the thin films are the composition of Tin (Sn) and Oxygen (O<sub>2</sub>). The optical band gap of SnO<sub>2 </sub>thin films deposited by CBD method, Drop-Cast method and Dip-Coating method is found to be 3.12 eV, 3.14 eV and 3.16 eV respectively. Thin films deposited by Dip-Coating method showed the highest band gap. The electrical results confirmed that the SnO<sub>2</sub> thin films are good conductors and pursued Ohm’s Law. These properties of the SnO<sub>2</sub> thin films brand are appropriate for application in solar cell assembly, gas sensor devices and transparent electrodes of panel displays.展开更多
Conductive polymer composites(CPCs)strain sensors exhibit promising applications in flexible electronics,people’s health monitoring,etc.It remains a big challenge to develop a simple and cost-effective method to prep...Conductive polymer composites(CPCs)strain sensors exhibit promising applications in flexible electronics,people’s health monitoring,etc.It remains a big challenge to develop a simple and cost-effective method to prepare CPCs with high conductivity,corrosion resistance,strong interfacial adhesion and high sensitivity.Here,we propose a facile“drop-casting and fluorination”strategy to fabricate superhydrophobic and highly electrically conductive coating by Ag precursor adsorption onto a commercially available elastic tape,subsequent chemical reduction and final fluorination.The Ag nanoparticles could not only construct the electrically conductive network but also greatly enhance the surface roughness.The contact angle and electrical conductivity of the coating can reach as high as 156°and 126 S/cm,respectively.When used for strain sensing,the superhydrophobic and conductive coating shows a high gauger factor(up to 7631 with the strain from 44%to 50%)and outstanding recyclability.The strain sensor could monitor different body joint motions with the stable and reliable sensing signals even after long time treatment in a corrosive solution.展开更多
Herein we report CO_(2) electrochemical reduction reaction(CO_(2) ERR)on the cobalt tetraphenylporphyrin(Co TPP)modified TiO_(2) nanotube(TNT)electrode.It was found the axial coordination of drop-casting solvent to Co...Herein we report CO_(2) electrochemical reduction reaction(CO_(2) ERR)on the cobalt tetraphenylporphyrin(Co TPP)modified TiO_(2) nanotube(TNT)electrode.It was found the axial coordination of drop-casting solvent to Co TPP and the porphyrin structure are the major factors that have significant effects on the catalytic performance of the electrode.As confirmed by spectrophotometric titration,pyridine has a stronger coordination bond to Co TPP than DMF and THF thus leading to the highest efficiency among the dropcasting solvents tested in the study.Based on the spectrophotometric analysis,possible coordination mechanism between drop-casting solvents and Co TPP is put forward.On the other hand,introduction of-COOMe substituents in phenyl rings of Co TPP weakens the coordination bond between pyridine and Co TPP as clearly evidenced by deuterium NMR spectra,resulting in a detrimental effect on CO_(2) ERR.Therefore,the manipulation of the coordination environment around the metal center of immobilized catalyst is crucial in designing an efficient electrocatalytic system.展开更多
Here in this paper, we demonstrate a facile technique for creating the mixed formamidinium（HN = CHNH_3~＋, FA~＋）and methylammonium（CH_3NH_3~＋, MA~＋） cations in the lead iodide perovskite. This technique entails...Here in this paper, we demonstrate a facile technique for creating the mixed formamidinium（HN = CHNH_3~＋, FA~＋）and methylammonium（CH_3NH_3~＋, MA~＋） cations in the lead iodide perovskite. This technique entails a facile drop-casting of formamidinium iodide（FAI） solutions on as-prepared MAPbI_3 perovskite thin films under the controlled conditions,which leads to controllable displacement of the MA~＋ cations by FA~＋ cations in the perovskite structure at room temperature. Uniform and controllable mixed organic cation perovskite thin films without a ＂bi-layered＂ or graded structure are achieved. By applying this approach to photovoltaic devices, we are able to improve the performances of devices through extending their optical-absorption onset further into the infrared region to enhance solar-light harvesting. Additionally,this work provides a simple and efficient technique to tune the structural, electrical, and optoelectronic properties of the light-harvesting materials for high-performance perovskite solar cells.展开更多
Co9Se8 nanosheets are synthesized via a solvothermal reaction.Thin films of Co9Se8 nanosheets are respectively fabricated through drop-cast and in situ growth for use as the electrocatalyst in dye-sensitized solar cel...Co9Se8 nanosheets are synthesized via a solvothermal reaction.Thin films of Co9Se8 nanosheets are respectively fabricated through drop-cast and in situ growth for use as the electrocatalyst in dye-sensitized solar cells （DSSCs）.Comparative studies reveal that the in situ growth Co9Se8 nanosheets film exhibits higher electrocatalytic activity for the electrocatalytic reduction of triiodide to iodide and better electrochemical stability than the drop-casted film.When applied as the counter electrode in DSSCs,the in situ growth film yields higher power conversion efficiency （8.65%） than the drop-casted film （5.87%） and even outperforms the reference Pt electrode （8.16%） under comparable conditions.展开更多
Vertically aligned p-silicon nanowire （SiNW） arrays have been extensively investigated in recent years as promising photocathodes for solar-driven hydrogen evolution. However, the fabrication of SiNW photocathodes w...Vertically aligned p-silicon nanowire （SiNW） arrays have been extensively investigated in recent years as promising photocathodes for solar-driven hydrogen evolution. However, the fabrication of SiNW photocathodes with both high photoelectrocatalytic activity and long-term operational stability using a simple and affordable approach is a challenging task. Herein, we report conformal and continuous deposition of a di-cobalt phosphide （C02P） layer on lithography- patterned highly ordered SiNW arrays via a cost-effective drop-casting method followed by a low-temperature phosphorization treatment. The as-deposited C02P layer consists of crystalline nanoparticles and has an intimate contact with SiNWs, forming a well-defined SiNW@Co2P core/shell nanostructure. The conformal and continuous Co2P layer functions as a highly efficient catalyst capable of substantially improving the photoelectrocatalytic activity for the hydrogen evolution reaction （HER） and effectively passivates the SiNWs to protect them from photo-oxidation, thus prolonging the lifetime of the electrode. As a consequence, the SiNW@Co2P photocathode with an optimized C02P layer thickness exhibits a high photocurrent density of -21.9 mA·cm^-2 at 0 V versus reversible hydrogen electrode and excellent operational stability up to 20 h for solar-driven hydrogen evolution, outperforming many nanostructured silicon photocathodes reported in the literature. The combination of passivation and catalytic functions in a single continuous layer represents a promising strategy for designing high-performance semiconductor photoelectrodes for use in solar-driven water splitting, which may simplify fabrication procedures and potentially reduce production costs.展开更多
In this study,a novel photovoltaic cell based on the Ti_(3)C_(2)T_(x) MXene/n-type silicon(n-Si)Schottky junction is developed by a simple solution-processed method of drop-casting the Ti_(3)C_(2)T_(x) MXene ethanol s...In this study,a novel photovoltaic cell based on the Ti_(3)C_(2)T_(x) MXene/n-type silicon(n-Si)Schottky junction is developed by a simple solution-processed method of drop-casting the Ti_(3)C_(2)T_(x) MXene ethanol suspension onto the surface of n-Si wafers and the subsequent natural drying in air.The demonstration device with a simple configuration of Ag(top electrode)/Ti_(3)C_(2)T_(x)/n-Si/In:Ga(back electrode)delivers a power conversion efficiency(PCE)of 5.70%with a short-circuit current density(Jsc)of 20.68 mA cm^(−2),open-circuit voltage(V_(oc))of 0.530 V and fill factor(FF)of 52.0%under AM 1.5G illumination.After treating the MXene layer with the SnCl_(2) aqueous solution,an improved PCE to 6.95%(J_(sc):23.04 mA cm^(−2);V_(oc):0.536 V;FF:56.2%)can be achieved because of the reduced light reflection,improved quality of junction and electrical contact,as well as the increased carrier lifetime/suppressed carrier recombination.Given the simple device configuration,facile preparation and huge potential for performance improvement,this work is believed to provide valuable exploration of developing novel solar cells.展开更多
基金supported by the National Basic Research Program of China(973 Program)with no.2011CB706900the National Nature Science Foundation of China(nos.50872149 and 50502003)+1 种基金the Scientific Research Foundation for Returned Scholars within the Ministry of Education of Chinathe Presidential Foundation of the Graduate University of the Chinese Academy of Sciences
文摘In this work,uniform reduced graphene oxide（RGO） films were formed on poly-（ethylene terephthalate）（PET） substrates using a simple drop-casting method.We investigated four types of substrates：unmodified PET,polydopamine-coated PET.carboxyl-group-modified PET,and alkyl-group-modified PET.Upon water evaporation,the surface of the polydopamine-modified PET substrates can interact with the reduced graphene oxide sheets to form flattened and continuous RGO films,which exhibit a sheet resistance of 21.75 kΩ/sq at 82% transmittance.The result indicates that the properties of the surface groups determined whether uniform and flattened RGO films could be formed on the substrates.Hence,we proposed a simple and effective way to produce transparent and conductive films in which the catechol unit exhibits a great effect on the deposition of uniform RGO films on PET substrates.
基金We acknowledge the General Research Fund(No.CityU 11306520)the Theme based Research(No.T42-103/16-N)of the Research Grants Council of Hong Kong,Chinathe Foshan Innovative and Entrepreneurial Research Team Program(No.2018IT100031).
文摘Due to the exciting photoelectric properties,better stability,and environmental-friendly nature,all-inorganic halide perovskites(AIHPs),especially the lead-free perovskites,have attracted worldwide attention.However,the film quality of AIHPs fabricated by typical spin-coating and subsequent high-temperature annealing is still not satisfactory,restricting their further development.Herein,we demonstrate a simple low-temperature solution-processed drop-casting method to achieve highly-crystalline cubic CsPbBr_(3)and lead-free layer-structured Cs_(3)Sb_(2)I_(9)microcrystals(MCs).This drop-casting technique not only consumes the less amount of precursor solution but also eliminates the high-temperature annealing as compared with those of spin coating.When these MCs are configured into photodetectors,they exhibit superior device performance,which is in distinct contrast to the one of spin-coated counterparts.Specifically,the responsivity of CsPbBr_(3)MCs is found to be as large as 8,990 mA/W,being 13 times larger than the spin-coated films and even better than many state-of-the-art solution-processed AIHPs devices.This device performance enhancement is attributed to the better film quality and phase purity obtained by the drop-casting method.All these results can evidently fill the“technology gap”for further enhancing the material quality of solution-processed AIHPs and breaking down the barriers that hinder the development of AIHPs based optoelectronic devices.
文摘Tin oxide (SnO<sub>2</sub>) thin films were deposited on glass substrate by Chemical Bath Deposition (CBD), Drop-Cast and Dip-Coating method. The thin films were post-annealed at 500°C for 2 hours. The structural, optical, and electrical properties of the SnO<sub>2</sub> thin films were investigated by using XRD, FTIR, SEM, EDX, UV-Vis spectroscopy, and Electrometer experiment. The XRD patterns of SnO<sub>2</sub> thin films deposited on glass substrate by CBD method, Drop-Cast method and Dip-Coating method showed cubic, tetragonal and amorphous structures respectively. The FTIR spectrum exhibited the strong presence of SnO<sub>2</sub> with the characteristic vibrational mode of Sn-O-Sn. The SEM analysis was observed that the surface morphology of the thin films toughly depends on the deposition methods of the SnO<sub>2</sub> thin films. EDX measurement confirmed that the thin films are the composition of Tin (Sn) and Oxygen (O<sub>2</sub>). The optical band gap of SnO<sub>2 </sub>thin films deposited by CBD method, Drop-Cast method and Dip-Coating method is found to be 3.12 eV, 3.14 eV and 3.16 eV respectively. Thin films deposited by Dip-Coating method showed the highest band gap. The electrical results confirmed that the SnO<sub>2</sub> thin films are good conductors and pursued Ohm’s Law. These properties of the SnO<sub>2</sub> thin films brand are appropriate for application in solar cell assembly, gas sensor devices and transparent electrodes of panel displays.
基金Natural Science Foundation of China(No.51873178)the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(No.sklpme2020-4-03)+1 种基金Qing Lan Project of Yangzhou University and Jiangsu Province,High-end Talent Project of Yangzhou University,the Priority Academic Program Development of Jiangsu Higher Education Institutions,Postgraduate Research&Practice Innovation Program of Jiangsu province(No.KYCX18_2364,No.KYCX20_2977)Outstanding Doctoral Dissertation Fund of Yangzhou University.
文摘Conductive polymer composites(CPCs)strain sensors exhibit promising applications in flexible electronics,people’s health monitoring,etc.It remains a big challenge to develop a simple and cost-effective method to prepare CPCs with high conductivity,corrosion resistance,strong interfacial adhesion and high sensitivity.Here,we propose a facile“drop-casting and fluorination”strategy to fabricate superhydrophobic and highly electrically conductive coating by Ag precursor adsorption onto a commercially available elastic tape,subsequent chemical reduction and final fluorination.The Ag nanoparticles could not only construct the electrically conductive network but also greatly enhance the surface roughness.The contact angle and electrical conductivity of the coating can reach as high as 156°and 126 S/cm,respectively.When used for strain sensing,the superhydrophobic and conductive coating shows a high gauger factor(up to 7631 with the strain from 44%to 50%)and outstanding recyclability.The strain sensor could monitor different body joint motions with the stable and reliable sensing signals even after long time treatment in a corrosive solution.
基金Financial support from the ARC Discovery Project(DP1901013720)。
文摘Herein we report CO_(2) electrochemical reduction reaction(CO_(2) ERR)on the cobalt tetraphenylporphyrin(Co TPP)modified TiO_(2) nanotube(TNT)electrode.It was found the axial coordination of drop-casting solvent to Co TPP and the porphyrin structure are the major factors that have significant effects on the catalytic performance of the electrode.As confirmed by spectrophotometric titration,pyridine has a stronger coordination bond to Co TPP than DMF and THF thus leading to the highest efficiency among the dropcasting solvents tested in the study.Based on the spectrophotometric analysis,possible coordination mechanism between drop-casting solvents and Co TPP is put forward.On the other hand,introduction of-COOMe substituents in phenyl rings of Co TPP weakens the coordination bond between pyridine and Co TPP as clearly evidenced by deuterium NMR spectra,resulting in a detrimental effect on CO_(2) ERR.Therefore,the manipulation of the coordination environment around the metal center of immobilized catalyst is crucial in designing an efficient electrocatalytic system.
基金Project supported by the Fundamental Research Funds for the Central Universities,China(Grant No.2015QNA09)
文摘Here in this paper, we demonstrate a facile technique for creating the mixed formamidinium（HN = CHNH_3~＋, FA~＋）and methylammonium（CH_3NH_3~＋, MA~＋） cations in the lead iodide perovskite. This technique entails a facile drop-casting of formamidinium iodide（FAI） solutions on as-prepared MAPbI_3 perovskite thin films under the controlled conditions,which leads to controllable displacement of the MA~＋ cations by FA~＋ cations in the perovskite structure at room temperature. Uniform and controllable mixed organic cation perovskite thin films without a ＂bi-layered＂ or graded structure are achieved. By applying this approach to photovoltaic devices, we are able to improve the performances of devices through extending their optical-absorption onset further into the infrared region to enhance solar-light harvesting. Additionally,this work provides a simple and efficient technique to tune the structural, electrical, and optoelectronic properties of the light-harvesting materials for high-performance perovskite solar cells.
文摘Co9Se8 nanosheets are synthesized via a solvothermal reaction.Thin films of Co9Se8 nanosheets are respectively fabricated through drop-cast and in situ growth for use as the electrocatalyst in dye-sensitized solar cells （DSSCs）.Comparative studies reveal that the in situ growth Co9Se8 nanosheets film exhibits higher electrocatalytic activity for the electrocatalytic reduction of triiodide to iodide and better electrochemical stability than the drop-casted film.When applied as the counter electrode in DSSCs,the in situ growth film yields higher power conversion efficiency （8.65%） than the drop-casted film （5.87%） and even outperforms the reference Pt electrode （8.16%） under comparable conditions.
文摘Vertically aligned p-silicon nanowire （SiNW） arrays have been extensively investigated in recent years as promising photocathodes for solar-driven hydrogen evolution. However, the fabrication of SiNW photocathodes with both high photoelectrocatalytic activity and long-term operational stability using a simple and affordable approach is a challenging task. Herein, we report conformal and continuous deposition of a di-cobalt phosphide （C02P） layer on lithography- patterned highly ordered SiNW arrays via a cost-effective drop-casting method followed by a low-temperature phosphorization treatment. The as-deposited C02P layer consists of crystalline nanoparticles and has an intimate contact with SiNWs, forming a well-defined SiNW@Co2P core/shell nanostructure. The conformal and continuous Co2P layer functions as a highly efficient catalyst capable of substantially improving the photoelectrocatalytic activity for the hydrogen evolution reaction （HER） and effectively passivates the SiNWs to protect them from photo-oxidation, thus prolonging the lifetime of the electrode. As a consequence, the SiNW@Co2P photocathode with an optimized C02P layer thickness exhibits a high photocurrent density of -21.9 mA·cm^-2 at 0 V versus reversible hydrogen electrode and excellent operational stability up to 20 h for solar-driven hydrogen evolution, outperforming many nanostructured silicon photocathodes reported in the literature. The combination of passivation and catalytic functions in a single continuous layer represents a promising strategy for designing high-performance semiconductor photoelectrodes for use in solar-driven water splitting, which may simplify fabrication procedures and potentially reduce production costs.
基金financially supported by the Natural Science Foundation of Gansu(20JR10RA611)。
文摘In this study,a novel photovoltaic cell based on the Ti_(3)C_(2)T_(x) MXene/n-type silicon(n-Si)Schottky junction is developed by a simple solution-processed method of drop-casting the Ti_(3)C_(2)T_(x) MXene ethanol suspension onto the surface of n-Si wafers and the subsequent natural drying in air.The demonstration device with a simple configuration of Ag(top electrode)/Ti_(3)C_(2)T_(x)/n-Si/In:Ga(back electrode)delivers a power conversion efficiency(PCE)of 5.70%with a short-circuit current density(Jsc)of 20.68 mA cm^(−2),open-circuit voltage(V_(oc))of 0.530 V and fill factor(FF)of 52.0%under AM 1.5G illumination.After treating the MXene layer with the SnCl_(2) aqueous solution,an improved PCE to 6.95%(J_(sc):23.04 mA cm^(−2);V_(oc):0.536 V;FF:56.2%)can be achieved because of the reduced light reflection,improved quality of junction and electrical contact,as well as the increased carrier lifetime/suppressed carrier recombination.Given the simple device configuration,facile preparation and huge potential for performance improvement,this work is believed to provide valuable exploration of developing novel solar cells.
