Jinwei Gao - Academia.edu (original) (raw)

Papers by Jinwei Gao

Research paper thumbnail of Nanostructures for Flexible Electronics and Drug Delivery

Journal of Nanomaterials, 2017

Research paper thumbnail of Transparent Conductive Electrodes: Uniform Self-Forming Metallic Network as a High-Performance Transparent Conductive Electrode (Adv. Mater. 6/2014)

Research paper thumbnail of Reversible temperature regulation of electrical and thermal conductivity using liquid–solid phase transitions

Nature Communications, 2011

Reversible temperature tuning of electrical and thermal conductivities of materials is of interes... more Reversible temperature tuning of electrical and thermal conductivities of materials is of interest for many applications, including seasonal regulation of building temperature, thermal storage and sensors. Here we introduce a general strategy to achieve large contrasts in electrical and thermal conductivities using first-order phase transitions in percolated composite materials. Internal stress generated during a phase transition modulates the electrical and thermal contact resistances, leading to large contrasts in the electrical and thermal conductivities at the phase transition temperature. With graphite/hexadecane suspensions, the electrical conductivity changes 2 orders of magnitude and the thermal conductivity varies up to 3.2 times near 18 °C. The generality of the approach is also demonstrated in other materials such as graphite/water and carbon nanotube/hexadecane suspensions.

Research paper thumbnail of Understanding the effect of antisolvent on processing window and efficiency for large-area flexible perovskite solar cells

Materials Today Physics, 2021

One-step method assisted by antisolvent is the most useful strategy to fabricate perovskite solar... more One-step method assisted by antisolvent is the most useful strategy to fabricate perovskite solar cells (PSCs) with high power conversion efficiency (PCE). Nevertheless, the narrow processing window and strict solvent ratio limit the preparation of large-area and uniform perovskite films. Herein, by thorough in-depth study of the interaction between solvents and antisolvents in the film preparation process, we found that the typical dimethylformamide solvent plays an important role in the antisolvent washing process. We demonstrate a solvent-antisolvent interaction model to understand the originality of the narrow processing window and solvent ratio based on chlorobenzene. Here, a green antisolvent e Ethyl Methyl Carbonate is introduced to widen a processing window from 2s to 35s and extend the volume ratio of dimethylformamide: dimethyl sulfoxide varying from 7:3 to 0:10 in the precursor solution. The obtained PSCs show a remarkable efficiency of 22.08% on rigid substrates, and 19.14% on flexible substrates. In a parallel effort, we demonstrate a uniform and large-area (6 Â 6 cm 2) flexible perovskite solar cell, exhibiting the highest PCE of 18.60%.

Research paper thumbnail of Solution-processing interface layers for high performance perovskite solar cells

Asia Communications and Photonics Conference

Research paper thumbnail of Investigation on Thermal Conductivity and Ac Impedance of Graphite Suspension Investigation on Thermal Conductivity and Ac Impedance of Graphite Suspension Acknowledgements

Over the past decade, some groups have reported that nanofluids, which are liquids containing sus... more Over the past decade, some groups have reported that nanofluids, which are liquids containing suspensions of nanoparticles, have substantially higher thermal conductivity than that of the base fluids. However, the reported high thermal conductivity sometimes cannot be reproduced. Theoretically, potential mechanisms leading to this enhancement are still under scrutiny. In this thesis, we present experimental studies aiming at understanding heat conduction mechanisms in nanofluids. We use graphite flakes as additives and developed methods to prepare stable graphite suspensions. The thermal conductivity enhancement of our suspensions achieved record high thermal conductivity values in different base fluids including water, engine oil, and ethylene glycol. This thesis investigates the effect of graphite flake preparation methods such as microwave and ultrasonic on the thermal conductivity of the suspensions, and found that graphite flakes of tens of nanometer in thickness but tens of mi...

Research paper thumbnail of Highly Reproducible Fabrication of Perovskite Films with an Ultrawide Antisolvent Dripping Window for Large‐Scale Flexible Solar Cells

Research paper thumbnail of Machine learning-guided search for high-efficiency perovskite solar cells with doped electron transport layers

Journal of Materials Chemistry A

Experimental search for high-efficiency perovskite solar cells (PSCs) is an extremely challenging... more Experimental search for high-efficiency perovskite solar cells (PSCs) is an extremely challenging task due to the vast search space comprising the materials, device structures, and preparation methods. Herein, by using...

Research paper thumbnail of Grand Challenges in Nanofabrication: There Remains Plenty of Room at the Bottom

Frontiers in Nanotechnology

Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, United States... more Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, United States, Institute for Physical Science and Technology, University of Maryland, College Park, MD, United States, Institute for AdvancedMaterials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, China, Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States, Institute of Inorganic Chemistry, Graz University of Technology, Graz, Austria, Department of Physics, Boston College, Chestnut Hill, MA, United States, APPM-MCA AttoLab, imec, Leuven, Belgium, Yale Cleanroom, Department of Applied Physics, Yale University, New Haven, CT, United States, KLA Corporation, Concorezzo, Italy, Walker Department of Mechanical Engineering, Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX, United States

Research paper thumbnail of Equivalent cation substitution-triggered highly efficient Mn4+ red emission in double-perovskite type (Ba, Sr)2(Gd, La, Y, Lu)(Nb, Sb)O6:Mn4+ solid solution phosphors and photophysical studies

Chemical Engineering Journal

Research paper thumbnail of A Safe Flexible Self-Powered Wristband System by Integrating Defective MnO2–x Nanosheet-Based Zinc-Ion Batteries with Perovskite Solar Cells

ACS Nano

The booming market of portable and wearable electronics has aroused the requests for advanced fle... more The booming market of portable and wearable electronics has aroused the requests for advanced flexible self-powered energy systems featuring both excellent performance and high safety. Herein, we report a safe, flexible, self-powered wristband system by integrating high-performance zinc-ion batteries (ZIBs) with perovskite solar cells (PSCs). ZIBs were first fabricated on the basis of a defective MnO2-x nanosheet-grown carbon cloth (MnO2-x@CC), which was obtained via the simple lithium treatment of the MnO2 nanosheets to slightly expand the interlayer spacing and generate rich oxygen vacancies. When used as a ZIB cathode, the MnO2-x@CC with a ultrahigh mass loading (up to 25.5 mg cm-2) exhibits a much enhanced specific capacity (3.63 mAh cm-2 at current density of 3.93 mA cm-2), rate performance, and long cycle stability (no obvious degradation after 5000 cycles) than those of the MnO2@CC. Importantly, the MnO2-x@CC-based quasi-solid-state ZIB not only achieves excellent flexibility and an ultrahigh energy density of 5.11 mWh cm-2 (59.42 mWh cm-3) but also presents a high safety under a wide temperature range and various severe conditions. More importantly, the flexible ZIBs can be integrated with flexible PSCs to construct a safe, self-powered wristband, which is able to harvest light energy and power a commercial smart bracelet. This work sheds light on the development of high-performance ZIB cathodes and thus offers a good strategy to construct wearable self-powered energy systems for wearable electronics.

Research paper thumbnail of Lanthanide molecular model triggers sequential sensing performance

Journal of Molecular Liquids

Research paper thumbnail of High-efficient smart windows enabled by self-forming fractal networks and electrophoresis of core-shell TiO2@SiO2 particles

Research paper thumbnail of Fluorescence Determination of Ni2+ Ions Based on a Novel Nano-Platform Derived from Silicon Quantum Dots

Silicon

Quantum dots generate unique luminescent and chemical properties due to the ultra-small particle ... more Quantum dots generate unique luminescent and chemical properties due to the ultra-small particle sizes. In this contribution, a novel silicon nanoparticles (Si-NPs)-based platform has been established via (3-aminopropyl) trimethoxysilane (APS) and ascorbic acid (AA) as raw materials within only 30 min. A switched off effect has been achieved for the determination of Ni2+ ions and the strategy has been simply realized by recording the luminescence changes in the green band of Si-NPs. This developed approach possesses a variety of merits such as label free, low cost, easy post-treatment and convenient operations. The linear equation range is yielded between 0 and 20 μM with the detection limit of 1.73 μM. The nano-sensor provides a versatile route for the monitoring of mercury ions in practical environments.

Research paper thumbnail of Fluorinated interfacial layers in perovskite solar cells: efficient enhancement of the fill factor

Journal of Materials Chemistry A

A series of novel fluorinated small molecules have been designed and used as interfacial material... more A series of novel fluorinated small molecules have been designed and used as interfacial materials to improve the contact between perovskite and spiro-OMeTAD, with an enhanced PCE enabling by a significant FF, up to ∼80%.

Research paper thumbnail of Effects of Ambient Gases on the Electrical Performance of Solution-Processed C8-BTBT Thin-Film Transistors

Nanoscale Research Letters

We performed a systematic study of the influence of environmental conditions on the electrical pe... more We performed a systematic study of the influence of environmental conditions on the electrical performance characteristics of solution-processed 2,7-dioctyl [1] benzothieno[3,2-b][1]-benzothiophene (C8-BTBT) thin-film transistors (TFTs). Four environmental exposure conditions were considered: high vacuum (HV), O 2 , N 2 , and air. The devices exposed to O 2 and N 2 for 2 h performed in a manner similar to that of the device kept in HV. However, the device exposed to air for 2 h exhibited significantly better electrical properties than its counterparts. The average and highest carrier mobility of the 70 air-exposed C8-BTBT TFTs were 4.82 and 8.07 cm 2 V-1 s-1 , respectively. This can be compared to 2.76 cm 2 V-1 s-1 and 4.70 cm 2 V-1 s-1 , respectively, for the 70 devices kept in HV. Furthermore, device air stability was investigated. The electrical performance of C8-BTBT TFTs degrades after long periods of air exposure. Our work improves knowledge of charge transport behavior and mechanisms in C8-BTBT OTFTs. It also provides ideas that may help to improve device electrical performance further.

Research paper thumbnail of In vitro and in vivo studies of a chlorin-based carbon nanocarrier with photodynamic therapy features

Photochemical & Photobiological Sciences

Carbonaceous materials have long been developed to utilize “nano-spaces” and numerous guest speci... more Carbonaceous materials have long been developed to utilize “nano-spaces” and numerous guest species could be encapsulated.

Research paper thumbnail of Room-Temperature-Processed ZrO2 Interlayer toward Efficient Planar Perovskite Solar Cells

ACS Applied Energy Materials

The Sn-doped In 2 O 3 transparent conductive [indium tin oxide (ITO)] electrode in planar perovsk... more The Sn-doped In 2 O 3 transparent conductive [indium tin oxide (ITO)] electrode in planar perovskite solar cells (PSCs) is modified by a zirconia (ZrO 2) interlayer with a low-temperature process. Here, the ZrO 2 film is prepared by ultraviolet (UV) treatment at room temperature. The effects of the inserted ZrO 2 interlayer on the performance of CH 3 NH 3 PbI 3−x Cl x-based PSCs have been systemically studied. After optimizing the process, the champion efficiency of PSCs with a UV-treated ZrO 2 interlayer is 19.48%, which is larger than that of the reference PSC (15.56%). The improved performance in the modified devices is primarily ascribed to the reduced trap states and the suppressed carrier recombination at the ITO/SnO 2 interface. Our work provides a facile route to boost the photovoltaic performance of PSCs by modifying the surface of the transparent conductive electrode at room temperature.

Research paper thumbnail of Microstructure Simulation and Constitutive Modelling of Magnetorheological Fluids Based on the Hexagonal Close-packed Structure

Materials

This paper presents a new constitutive model of high particles concentrated magnetorheological fl... more This paper presents a new constitutive model of high particles concentrated magnetorheological fluids (MRFs) that is based on the hexagonal close-packed structure, which can reflect the micro-structures of the particles under the magnetic field. Firstly, the particle dynamic simulations for the forces sustained by carbonyl iron powder (CIP) particles of MRFs are performed in order to investigate the particles chain-forming process at different time nodes. Subsequently, according to the force analyses, a hexagonal close-packed structure, which differs from the existing single-chain structure and body-cantered cubic structure, is adopted to formulate a constitutive model of MRFs with high concentration of the magnetic-responsive particles. Several experiments are performed while considering crucial factors that influence on the chain-forming mechanism and, hence, change the field-dependent shear yield stress in order to validate the proposed model. These factors include the magnetic i...

Research paper thumbnail of Numerical simulation and optimization of metallic network for highly efficient transparent conductive films

Journal of Applied Physics

Metallic networks have been regarded as one of the promising indium tin oxide replacements due to... more Metallic networks have been regarded as one of the promising indium tin oxide replacements due to its optoelectronic advantages and possible low-cost manufacturing cost. The electrothermal and optical properties of transparent conductive films (TCFs) are closely related to the geometry of the metallic networks. Therefore, the in-depth understanding of the geometry effect is quite important for designing a desirable metallic network TCF. In this paper, we conducted an in-depth theoretical study on the geometry effect on the electrothermal and optical properties of the metallic network TCF by using a coupled electrothermal model. We found that the metallic wire segments in different directions have different current densities and power densities, which mainly depends on the directions of the electric field. Besides, the inner corner of the branch junctions of networks has a current density 14.5 times higher than the average. The maximum temperature difference inside the network is up to 19.6 K. Importantly, the mechanisms for network breakdown under excessive operating power are summarized as thermal assisted electronic migration and excessive temperature. Finally, we proposed several optimized network geometries with a reduced sheet resistance (48.4%) and internal temperature difference (60.1%). We believed that the outcomes and analyses of this work help us to design the transparent metallic networks with optimal performance and potentially applicable to the transparent heaters and smart windows.Metallic networks have been regarded as one of the promising indium tin oxide replacements due to its optoelectronic advantages and possible low-cost manufacturing cost. The electrothermal and optical properties of transparent conductive films (TCFs) are closely related to the geometry of the metallic networks. Therefore, the in-depth understanding of the geometry effect is quite important for designing a desirable metallic network TCF. In this paper, we conducted an in-depth theoretical study on the geometry effect on the electrothermal and optical properties of the metallic network TCF by using a coupled electrothermal model. We found that the metallic wire segments in different directions have different current densities and power densities, which mainly depends on the directions of the electric field. Besides, the inner corner of the branch junctions of networks has a current density 14.5 times higher than the average. The maximum temperature difference inside the network is up to 19.6 K. Importantly,...

Research paper thumbnail of Nanostructures for Flexible Electronics and Drug Delivery

Journal of Nanomaterials, 2017

Research paper thumbnail of Transparent Conductive Electrodes: Uniform Self-Forming Metallic Network as a High-Performance Transparent Conductive Electrode (Adv. Mater. 6/2014)

Research paper thumbnail of Reversible temperature regulation of electrical and thermal conductivity using liquid–solid phase transitions

Nature Communications, 2011

Reversible temperature tuning of electrical and thermal conductivities of materials is of interes... more Reversible temperature tuning of electrical and thermal conductivities of materials is of interest for many applications, including seasonal regulation of building temperature, thermal storage and sensors. Here we introduce a general strategy to achieve large contrasts in electrical and thermal conductivities using first-order phase transitions in percolated composite materials. Internal stress generated during a phase transition modulates the electrical and thermal contact resistances, leading to large contrasts in the electrical and thermal conductivities at the phase transition temperature. With graphite/hexadecane suspensions, the electrical conductivity changes 2 orders of magnitude and the thermal conductivity varies up to 3.2 times near 18 °C. The generality of the approach is also demonstrated in other materials such as graphite/water and carbon nanotube/hexadecane suspensions.

Research paper thumbnail of Understanding the effect of antisolvent on processing window and efficiency for large-area flexible perovskite solar cells

Materials Today Physics, 2021

One-step method assisted by antisolvent is the most useful strategy to fabricate perovskite solar... more One-step method assisted by antisolvent is the most useful strategy to fabricate perovskite solar cells (PSCs) with high power conversion efficiency (PCE). Nevertheless, the narrow processing window and strict solvent ratio limit the preparation of large-area and uniform perovskite films. Herein, by thorough in-depth study of the interaction between solvents and antisolvents in the film preparation process, we found that the typical dimethylformamide solvent plays an important role in the antisolvent washing process. We demonstrate a solvent-antisolvent interaction model to understand the originality of the narrow processing window and solvent ratio based on chlorobenzene. Here, a green antisolvent e Ethyl Methyl Carbonate is introduced to widen a processing window from 2s to 35s and extend the volume ratio of dimethylformamide: dimethyl sulfoxide varying from 7:3 to 0:10 in the precursor solution. The obtained PSCs show a remarkable efficiency of 22.08% on rigid substrates, and 19.14% on flexible substrates. In a parallel effort, we demonstrate a uniform and large-area (6 Â 6 cm 2) flexible perovskite solar cell, exhibiting the highest PCE of 18.60%.

Research paper thumbnail of Solution-processing interface layers for high performance perovskite solar cells

Asia Communications and Photonics Conference

Research paper thumbnail of Investigation on Thermal Conductivity and Ac Impedance of Graphite Suspension Investigation on Thermal Conductivity and Ac Impedance of Graphite Suspension Acknowledgements

Over the past decade, some groups have reported that nanofluids, which are liquids containing sus... more Over the past decade, some groups have reported that nanofluids, which are liquids containing suspensions of nanoparticles, have substantially higher thermal conductivity than that of the base fluids. However, the reported high thermal conductivity sometimes cannot be reproduced. Theoretically, potential mechanisms leading to this enhancement are still under scrutiny. In this thesis, we present experimental studies aiming at understanding heat conduction mechanisms in nanofluids. We use graphite flakes as additives and developed methods to prepare stable graphite suspensions. The thermal conductivity enhancement of our suspensions achieved record high thermal conductivity values in different base fluids including water, engine oil, and ethylene glycol. This thesis investigates the effect of graphite flake preparation methods such as microwave and ultrasonic on the thermal conductivity of the suspensions, and found that graphite flakes of tens of nanometer in thickness but tens of mi...

Research paper thumbnail of Highly Reproducible Fabrication of Perovskite Films with an Ultrawide Antisolvent Dripping Window for Large‐Scale Flexible Solar Cells

Research paper thumbnail of Machine learning-guided search for high-efficiency perovskite solar cells with doped electron transport layers

Journal of Materials Chemistry A

Experimental search for high-efficiency perovskite solar cells (PSCs) is an extremely challenging... more Experimental search for high-efficiency perovskite solar cells (PSCs) is an extremely challenging task due to the vast search space comprising the materials, device structures, and preparation methods. Herein, by using...

Research paper thumbnail of Grand Challenges in Nanofabrication: There Remains Plenty of Room at the Bottom

Frontiers in Nanotechnology

Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, United States... more Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, United States, Institute for Physical Science and Technology, University of Maryland, College Park, MD, United States, Institute for AdvancedMaterials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, China, Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States, Institute of Inorganic Chemistry, Graz University of Technology, Graz, Austria, Department of Physics, Boston College, Chestnut Hill, MA, United States, APPM-MCA AttoLab, imec, Leuven, Belgium, Yale Cleanroom, Department of Applied Physics, Yale University, New Haven, CT, United States, KLA Corporation, Concorezzo, Italy, Walker Department of Mechanical Engineering, Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX, United States

Research paper thumbnail of Equivalent cation substitution-triggered highly efficient Mn4+ red emission in double-perovskite type (Ba, Sr)2(Gd, La, Y, Lu)(Nb, Sb)O6:Mn4+ solid solution phosphors and photophysical studies

Chemical Engineering Journal

Research paper thumbnail of A Safe Flexible Self-Powered Wristband System by Integrating Defective MnO2–x Nanosheet-Based Zinc-Ion Batteries with Perovskite Solar Cells

ACS Nano

The booming market of portable and wearable electronics has aroused the requests for advanced fle... more The booming market of portable and wearable electronics has aroused the requests for advanced flexible self-powered energy systems featuring both excellent performance and high safety. Herein, we report a safe, flexible, self-powered wristband system by integrating high-performance zinc-ion batteries (ZIBs) with perovskite solar cells (PSCs). ZIBs were first fabricated on the basis of a defective MnO2-x nanosheet-grown carbon cloth (MnO2-x@CC), which was obtained via the simple lithium treatment of the MnO2 nanosheets to slightly expand the interlayer spacing and generate rich oxygen vacancies. When used as a ZIB cathode, the MnO2-x@CC with a ultrahigh mass loading (up to 25.5 mg cm-2) exhibits a much enhanced specific capacity (3.63 mAh cm-2 at current density of 3.93 mA cm-2), rate performance, and long cycle stability (no obvious degradation after 5000 cycles) than those of the MnO2@CC. Importantly, the MnO2-x@CC-based quasi-solid-state ZIB not only achieves excellent flexibility and an ultrahigh energy density of 5.11 mWh cm-2 (59.42 mWh cm-3) but also presents a high safety under a wide temperature range and various severe conditions. More importantly, the flexible ZIBs can be integrated with flexible PSCs to construct a safe, self-powered wristband, which is able to harvest light energy and power a commercial smart bracelet. This work sheds light on the development of high-performance ZIB cathodes and thus offers a good strategy to construct wearable self-powered energy systems for wearable electronics.

Research paper thumbnail of Lanthanide molecular model triggers sequential sensing performance

Journal of Molecular Liquids

Research paper thumbnail of High-efficient smart windows enabled by self-forming fractal networks and electrophoresis of core-shell TiO2@SiO2 particles

Research paper thumbnail of Fluorescence Determination of Ni2+ Ions Based on a Novel Nano-Platform Derived from Silicon Quantum Dots

Silicon

Quantum dots generate unique luminescent and chemical properties due to the ultra-small particle ... more Quantum dots generate unique luminescent and chemical properties due to the ultra-small particle sizes. In this contribution, a novel silicon nanoparticles (Si-NPs)-based platform has been established via (3-aminopropyl) trimethoxysilane (APS) and ascorbic acid (AA) as raw materials within only 30 min. A switched off effect has been achieved for the determination of Ni2+ ions and the strategy has been simply realized by recording the luminescence changes in the green band of Si-NPs. This developed approach possesses a variety of merits such as label free, low cost, easy post-treatment and convenient operations. The linear equation range is yielded between 0 and 20 μM with the detection limit of 1.73 μM. The nano-sensor provides a versatile route for the monitoring of mercury ions in practical environments.

Research paper thumbnail of Fluorinated interfacial layers in perovskite solar cells: efficient enhancement of the fill factor

Journal of Materials Chemistry A

A series of novel fluorinated small molecules have been designed and used as interfacial material... more A series of novel fluorinated small molecules have been designed and used as interfacial materials to improve the contact between perovskite and spiro-OMeTAD, with an enhanced PCE enabling by a significant FF, up to ∼80%.

Research paper thumbnail of Effects of Ambient Gases on the Electrical Performance of Solution-Processed C8-BTBT Thin-Film Transistors

Nanoscale Research Letters

We performed a systematic study of the influence of environmental conditions on the electrical pe... more We performed a systematic study of the influence of environmental conditions on the electrical performance characteristics of solution-processed 2,7-dioctyl [1] benzothieno[3,2-b][1]-benzothiophene (C8-BTBT) thin-film transistors (TFTs). Four environmental exposure conditions were considered: high vacuum (HV), O 2 , N 2 , and air. The devices exposed to O 2 and N 2 for 2 h performed in a manner similar to that of the device kept in HV. However, the device exposed to air for 2 h exhibited significantly better electrical properties than its counterparts. The average and highest carrier mobility of the 70 air-exposed C8-BTBT TFTs were 4.82 and 8.07 cm 2 V-1 s-1 , respectively. This can be compared to 2.76 cm 2 V-1 s-1 and 4.70 cm 2 V-1 s-1 , respectively, for the 70 devices kept in HV. Furthermore, device air stability was investigated. The electrical performance of C8-BTBT TFTs degrades after long periods of air exposure. Our work improves knowledge of charge transport behavior and mechanisms in C8-BTBT OTFTs. It also provides ideas that may help to improve device electrical performance further.

Research paper thumbnail of In vitro and in vivo studies of a chlorin-based carbon nanocarrier with photodynamic therapy features

Photochemical & Photobiological Sciences

Carbonaceous materials have long been developed to utilize “nano-spaces” and numerous guest speci... more Carbonaceous materials have long been developed to utilize “nano-spaces” and numerous guest species could be encapsulated.

Research paper thumbnail of Room-Temperature-Processed ZrO2 Interlayer toward Efficient Planar Perovskite Solar Cells

ACS Applied Energy Materials

The Sn-doped In 2 O 3 transparent conductive [indium tin oxide (ITO)] electrode in planar perovsk... more The Sn-doped In 2 O 3 transparent conductive [indium tin oxide (ITO)] electrode in planar perovskite solar cells (PSCs) is modified by a zirconia (ZrO 2) interlayer with a low-temperature process. Here, the ZrO 2 film is prepared by ultraviolet (UV) treatment at room temperature. The effects of the inserted ZrO 2 interlayer on the performance of CH 3 NH 3 PbI 3−x Cl x-based PSCs have been systemically studied. After optimizing the process, the champion efficiency of PSCs with a UV-treated ZrO 2 interlayer is 19.48%, which is larger than that of the reference PSC (15.56%). The improved performance in the modified devices is primarily ascribed to the reduced trap states and the suppressed carrier recombination at the ITO/SnO 2 interface. Our work provides a facile route to boost the photovoltaic performance of PSCs by modifying the surface of the transparent conductive electrode at room temperature.

Research paper thumbnail of Microstructure Simulation and Constitutive Modelling of Magnetorheological Fluids Based on the Hexagonal Close-packed Structure

Materials

This paper presents a new constitutive model of high particles concentrated magnetorheological fl... more This paper presents a new constitutive model of high particles concentrated magnetorheological fluids (MRFs) that is based on the hexagonal close-packed structure, which can reflect the micro-structures of the particles under the magnetic field. Firstly, the particle dynamic simulations for the forces sustained by carbonyl iron powder (CIP) particles of MRFs are performed in order to investigate the particles chain-forming process at different time nodes. Subsequently, according to the force analyses, a hexagonal close-packed structure, which differs from the existing single-chain structure and body-cantered cubic structure, is adopted to formulate a constitutive model of MRFs with high concentration of the magnetic-responsive particles. Several experiments are performed while considering crucial factors that influence on the chain-forming mechanism and, hence, change the field-dependent shear yield stress in order to validate the proposed model. These factors include the magnetic i...

Research paper thumbnail of Numerical simulation and optimization of metallic network for highly efficient transparent conductive films

Journal of Applied Physics

Metallic networks have been regarded as one of the promising indium tin oxide replacements due to... more Metallic networks have been regarded as one of the promising indium tin oxide replacements due to its optoelectronic advantages and possible low-cost manufacturing cost. The electrothermal and optical properties of transparent conductive films (TCFs) are closely related to the geometry of the metallic networks. Therefore, the in-depth understanding of the geometry effect is quite important for designing a desirable metallic network TCF. In this paper, we conducted an in-depth theoretical study on the geometry effect on the electrothermal and optical properties of the metallic network TCF by using a coupled electrothermal model. We found that the metallic wire segments in different directions have different current densities and power densities, which mainly depends on the directions of the electric field. Besides, the inner corner of the branch junctions of networks has a current density 14.5 times higher than the average. The maximum temperature difference inside the network is up to 19.6 K. Importantly, the mechanisms for network breakdown under excessive operating power are summarized as thermal assisted electronic migration and excessive temperature. Finally, we proposed several optimized network geometries with a reduced sheet resistance (48.4%) and internal temperature difference (60.1%). We believed that the outcomes and analyses of this work help us to design the transparent metallic networks with optimal performance and potentially applicable to the transparent heaters and smart windows.Metallic networks have been regarded as one of the promising indium tin oxide replacements due to its optoelectronic advantages and possible low-cost manufacturing cost. The electrothermal and optical properties of transparent conductive films (TCFs) are closely related to the geometry of the metallic networks. Therefore, the in-depth understanding of the geometry effect is quite important for designing a desirable metallic network TCF. In this paper, we conducted an in-depth theoretical study on the geometry effect on the electrothermal and optical properties of the metallic network TCF by using a coupled electrothermal model. We found that the metallic wire segments in different directions have different current densities and power densities, which mainly depends on the directions of the electric field. Besides, the inner corner of the branch junctions of networks has a current density 14.5 times higher than the average. The maximum temperature difference inside the network is up to 19.6 K. Importantly,...