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Full-Text Articles in Physics

Swir Photodetection And Visualization Realized By Incorporating An Organic Swir Sensitive Bulk Heterojunction, Ning Li, Zhaojue Lan, Ying Suet Lau, Jiajuan Xue, Dahui Zhao, Furong Zhao Jul 2020

Swir Photodetection And Visualization Realized By Incorporating An Organic Swir Sensitive Bulk Heterojunction, Ning Li, Zhaojue Lan, Ying Suet Lau, Jiajuan Xue, Dahui Zhao, Furong Zhao

HKBU Staff Publication

Short‐wavelength infrared (SWIR) photodetection and visualization has profound impacts on different applications. In this work, a large‐area organic SWIR photodetector (PD) that is sensitive to SWIR light over a wavelength range from 1000 to 1600 nm and a SWIR visualization device that is capable of upconverting SWIR to visible light are developed. The organic SWIR PD, comprising an organic SWIR sensitive blend of a near‐infrared polymer and a nonfullerene n‐type small molecule SWIR dye, demonstrates an excellent capability for real‐time heart rate monitoring, offering an attractive opportunity for portable and wearable healthcare gadgets. The SWIR ...


Secular Changes In Atmospheric Turbidity Over Iraq And A Possible Link To Military Activity, Alexandra Chudnovsky, A. Kostinski May 2020

Secular Changes In Atmospheric Turbidity Over Iraq And A Possible Link To Military Activity, Alexandra Chudnovsky, A. Kostinski

Michigan Tech Publications

We examine satellite-derived aerosol optical depth (AOD) data during the period 2000-2018 over the Middle East to evaluate the contribution of anthropogenic pollution. We focus on Iraq, where US troops were present for nearly nine years. We begin with a plausibility argument linking anthropogenic influence and AOD signature. We then calculate the percent change in AOD every two years. To pinpoint the causes for changes in AOD on a spatial basis, we distinguish between synoptically "calm" periods and those with vigorous synoptic activity. This was done on high-resolution 10 km AOD retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor ...


Richardsite, Zn2cugas4, A New Gallium-Essential Member Of The Stannite Group From The Gem Mines Near Merelani, Tanzania, Luca Bindi, John A. Jaszczak May 2020

Richardsite, Zn2cugas4, A New Gallium-Essential Member Of The Stannite Group From The Gem Mines Near Merelani, Tanzania, Luca Bindi, John A. Jaszczak

Michigan Tech Publications

The new mineral richardsite occurs as overgrowths of small (50–400 μm) dark gray, disphenoidal crystals with no evident twinning, but epitaxically oriented on wurtzite–sphalerite crystals from the gem mines near Merelani, Lelatema Mountains, Simanjiro District, Manyara Region, Tanzania. Associated minerals also include graphite, diopside, and Ge,Ga-rich wurtzite. It is brittle, dark gray in color, and has a metallic luster. It appears dark bluish gray in reflected plane-polarized light, and is moderately bireflectant. It is distinctly anisotropic with violet to light-blue rotation tints with crossed polarizers. Reflectance percentages for Rmin and Rmax in air at the respective wavelengths ...


Radiative Absorption Enhancements By Black Carbon Controlled By Particle-To-Particle Heterogeneity In Composition, Laura Fierce, Timothy B. Onasch, Christopher D. Cappa, Claudio Mazzoleni, Swarup China, Janarjan Bhandari, Et Al. Jan 2020

Radiative Absorption Enhancements By Black Carbon Controlled By Particle-To-Particle Heterogeneity In Composition, Laura Fierce, Timothy B. Onasch, Christopher D. Cappa, Claudio Mazzoleni, Swarup China, Janarjan Bhandari, Et Al.

Michigan Tech Publications

Black carbon (BC) absorbs solar radiation, leading to a strong but uncertain warming effect on climate. A key challenge in modeling and quantifying BC’s radiative effect on climate is predicting enhancements in light absorption that result from internal mixing between BC and other aerosol components. Modeling and laboratory studies show that BC, when mixed with other aerosol components, absorbs more strongly than pure, uncoated BC; however, some ambient observations suggest more variable and weaker absorption enhancement. We show that the lower-than-expected enhancements in ambient measurements result from a combination of two factors. First, the often used spherical, concentric core-shell ...


Phase Diagrams Of Polymer-Containing Liquid Mixtures With A Theory-Embedded Neural Network, Issei Nakamura Jan 2020

Phase Diagrams Of Polymer-Containing Liquid Mixtures With A Theory-Embedded Neural Network, Issei Nakamura

Michigan Tech Publications

We develop a deep neural network (DNN) that accounts for the phase behaviors of polymer-containing liquid mixtures. The key component in the DNN consists of a theory-embedded layer that captures the characteristic features of the phase behavior via coarse-grained mean-field theory and scaling laws and substantially enhances the accuracy of the DNN. Moreover, this layer enables us to reduce the size of the DNN for the phase diagrams of the mixtures. This study also presents the predictive power of the DNN for the phase behaviors of polymer solutions and salt-free and salt-doped diblock copolymer melts.


Near-Infrared And Visible Light Dual-Mode Organic Photodetectors, Zhaojue Lan, Yan Lian Lei, Wing Kin Edward Chan, Chen Shuming, Dan Luo, Furong Zhu Jan 2020

Near-Infrared And Visible Light Dual-Mode Organic Photodetectors, Zhaojue Lan, Yan Lian Lei, Wing Kin Edward Chan, Chen Shuming, Dan Luo, Furong Zhu

HKBU Staff Publication

We report a dual-mode organic photodetector (OPD) that has a trilayer visible light absorber/optical spacer/near-infrared (NIR) light absorber configuration. In the presence of NIR light, photocurrent is produced in the NIR light–absorbing layer due to the trap-assisted charge injection at the organic/cathode interface at a reverse bias. In the presence of visible light, photocurrent is produced in the visible light–absorbing layer, enabled by the trap-assisted charge injection at the anode/organic interface at a forward bias. A high responsivity of >10 A/W is obtained in both short and long wavelengths. The dual-mode OPD exhibits ...


Is Contact Nucleation Caused By Pressure Perturbation?, Fan Yang, Will Cantrell, Alexander Kostinski, Raymond Shaw, Andrew M. Vogelmann Dec 2019

Is Contact Nucleation Caused By Pressure Perturbation?, Fan Yang, Will Cantrell, Alexander Kostinski, Raymond Shaw, Andrew M. Vogelmann

Michigan Tech Publications

The reason why ice nucleation is more efficient by contact nucleation than by immersion nucleation has been elusive for over half a century. Six proposed mechanisms are summarized in this study. Among them, the pressure perturbation hypothesis, which arose from recent experiments, can qualitatively explain nearly all existing results relevant to contact nucleation. To explore the plausibility of this hypothesis in a more quantitative fashion and to guide future investigations, this study assessed the magnitude of pressure perturbation needed to cause contact nucleation and the associated spatial scales. The pressure perturbations needed were estimated using measured contact nucleation efficiencies for ...


Laboratory Study Of The Heterogeneous Ice Nucleation On Black-Carbon-Containing Aerosol, Leonid Nichman, Martin Wolf, Paul Davidovits, Timothy Onasch, Yue Zhang, Doug Worsnop, Janarjan Bhandari, Claudio Mazzoleni, Daniel Cziczo Oct 2019

Laboratory Study Of The Heterogeneous Ice Nucleation On Black-Carbon-Containing Aerosol, Leonid Nichman, Martin Wolf, Paul Davidovits, Timothy Onasch, Yue Zhang, Doug Worsnop, Janarjan Bhandari, Claudio Mazzoleni, Daniel Cziczo

Michigan Tech Publications

Soot and black carbon (BC) particles are generated in the incomplete combustion of fossil fuels, biomass, and biofuels. These airborne particles affect air quality, human health, aerosol–cloud interactions, precipitation formation, and climate. At present, the climate effects of BC particles are not well understood. Their role in cloud formation is obscured by their chemical and physical variability and by the internal mixing states of these particles with other compounds. Ice nucleation in field studies is often difficult to interpret. Nonetheless, most field studies seem to suggest that BC particles are not efficient ice-nucleating particles (INPs). On the other hand ...


Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations, Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra K Dubey, Allison C Aiken, Rajan K Chakrabarty, Hans Moosmüller, Timothy B Onasch, Rahul A Zaveri, Barbara V Scarnato, Paulo Fialho, Claudio Mazzoleni Aug 2019

Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations, Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra K Dubey, Allison C Aiken, Rajan K Chakrabarty, Hans Moosmüller, Timothy B Onasch, Rahul A Zaveri, Barbara V Scarnato, Paulo Fialho, Claudio Mazzoleni

Michigan Tech Publications

Soot particles form during combustion of carbonaceous materials and impact climate and air quality. When freshly emitted, they are typically fractal-like aggregates. After atmospheric aging, they can act as cloud condensation nuclei, and water condensation or evaporation restructure them to more compact aggregates, affecting their optical, aerodynamic, and surface properties. Here we survey the morphology of ambient soot particles from various locations and different environmental and aging conditions. We used electron microscopy and show extensive soot compaction after cloud processing. We further performed laboratory experiments to simulate atmospheric cloud processing under controlled conditions. We find that soot particles sampled after ...


Astro2020 Apc White Paper: Elevating The Role Of Software As A Product Of The Research Enterprise, Arfon Smith, Dara Norman, Kelle Cruz, Vandana Desai, Eric Bellm, Robert J. Nemiroff, Et. Al. Jul 2019

Astro2020 Apc White Paper: Elevating The Role Of Software As A Product Of The Research Enterprise, Arfon Smith, Dara Norman, Kelle Cruz, Vandana Desai, Eric Bellm, Robert J. Nemiroff, Et. Al.

Michigan Tech Publications

Software is a critical part of modern research, and yet there are insufficient mechanisms in the scholarly ecosystem to acknowledge, cite, and measure the impact of research software. The majority of academic fields rely on a one-dimensional credit model whereby academic articles (and their associated citations) are the dominant factor in the success of a researcher's career. In the petabyte era of astronomical science, citing software and measuring its impact enables academia to retain and reward researchers that make significant software contributions. These highly skilled researchers must be retained to maximize the scientific return from petabyte-scale datasets. Evolving beyond ...


Searching For Dark Matter Sub-Structure With Hawc, A. U. Abeysekara, A. Albert, R. Alfaro, C. Alvarez, R. Arceo, J. C. Arteaga-Valazquez, Chad Brisbois, H. Fleischhack, Binita Hona, P. Huntemeyer, Et Al. Jul 2019

Searching For Dark Matter Sub-Structure With Hawc, A. U. Abeysekara, A. Albert, R. Alfaro, C. Alvarez, R. Arceo, J. C. Arteaga-Valazquez, Chad Brisbois, H. Fleischhack, Binita Hona, P. Huntemeyer, Et Al.

Michigan Tech Publications

Numerical simulations show that the dark matter halos surrounding galaxies are expected to contain many over-densities or sub-halos. The most massive of these sub-halos can be optically observed in the form of dwarf galaxies. However, most lower mass sub-halos are predicted to exist as dark dwarf galaxies: sub-halos like dwarf galaxies with no luminous counterpart. It may be possible to detect these unseen sub-halos from gamma-ray signals originating from dark matter annihilation. The High Altitude Water Cherenkov Observatory (HAWC) is a very high energy (500 GeV to >100 TeV) gamma ray detector with a wide field-of-view and near continuous duty ...


Scaling Of An Atmospheric Model To Simulate Turbulence And Cloud Microphysics In The Pi Chamber, Subin Thomas, Mikhail Ovichinnikov, Fan Yang, Dennis Van Der Voort, Will Cantrell, Steven K. Krueger, Raymond Shaw Jul 2019

Scaling Of An Atmospheric Model To Simulate Turbulence And Cloud Microphysics In The Pi Chamber, Subin Thomas, Mikhail Ovichinnikov, Fan Yang, Dennis Van Der Voort, Will Cantrell, Steven K. Krueger, Raymond Shaw

Michigan Tech Publications

The Pi Cloud Chamber offers a unique opportunity to study aerosol-cloud microphysics interactions in a steady-state, turbulent environment. In this work, an atmospheric large-eddy simulation (LES) model with spectral bin microphysics is scaled down to simulate these interactions, allowing comparison with experimental results. A simple scalar flux budget model is developed and used to explore the effect of sidewalls on the bulk mixing temperature, water vapor mixing ratio, and supersaturation. The scaled simulation and the simple scalar flux budget model produce comparable bulk mixing scalar values. The LES dynamics results are compared with particle image velocimetry measurements of turbulent kinetic ...


Turbulence-Induced Cloud Voids: Observation And Interpretation, Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz Apr 2019

Turbulence-Induced Cloud Voids: Observation And Interpretation, Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz

Michigan Tech Publications

The phenomenon of “cloud voids”, i.e., elongated volumes inside a cloud that are devoid of droplets, was observed with laser sheet photography in clouds at a mountain-top station. Two experimental cases, similar in turbulence conditions yet with diverse droplet size distributions and cloud void prevalence, are reported. A theoretical explanation is proposed based on the study of heavy inertial sedimenting particles inside a Burgers vortex. A general conclusion regarding void appearance is drawn from theoretical analysis. Numerical simulations of polydisperse droplet motion with realistic vortex parameters and Mie scattering visual effects accounted for can explain the presence of voids ...


Broadband Phototransistors Realised By Incorporating A Bi-Layer Perovskite/Nir Light Absorbing Polymer Channel, Ning Li, Yanlian Li, Wing Kin Edward Chan, Furong Zhu Apr 2019

Broadband Phototransistors Realised By Incorporating A Bi-Layer Perovskite/Nir Light Absorbing Polymer Channel, Ning Li, Yanlian Li, Wing Kin Edward Chan, Furong Zhu

HKBU Staff Publication

The high performing ultra violet (UV) to near infrared (NIR) light broadband phototransistors (PTs) are enabled by incorporating a bi-layer methylammonium lead triiodide (MAPbI3) perovskite/NIR light absorbing diketopyrrolopyrrole-dithienylthieno[3,2-b]thiophene (DPP-DTT) polymer channel. The bi-layer MAPbI3/DPP-DTT channel takes the advantages of (1) complementary absorption and (2) high charge transport efficiency of the two materials. The on- and off-state transfer characteristics of the bi-layer MAPbI3/DPP-DTT channel PTs, in the presence of different sources of UV, visible and NIR light, were analyzed. The bi-layer MAPbI3/DPP-DTT channel PTs possess simultaneously a specific detectivity (D*) of >109 Jones over ...


Hybrid Loss‐Compensated Plasmonic Device, Fatemeh Hosseini Alast, Mohsen Nikkhah, Xiao Li, Jack Ng, Amirhossein B. Ghasemi, Hamid Latifi, Kok Wai Cheah Mar 2019

Hybrid Loss‐Compensated Plasmonic Device, Fatemeh Hosseini Alast, Mohsen Nikkhah, Xiao Li, Jack Ng, Amirhossein B. Ghasemi, Hamid Latifi, Kok Wai Cheah

HKBU Staff Publication

Here it is studied how the active medium affects the Rabi‐analog splitting when an active plasmonic microcavity mode is coupled to a surface plasmon polariton mode. The incorporation of Rubrene‐like molecules in the plasmonic microcavity results in stronger modal coupling. Anticrossing is observed with a large Rabi‐analog splitting energy of 280 meV in the strong coupling regime. The active medium contributes to the split enhancement through channeling more energy toward the coupling. The variation of photoluminescence emission and exciton‐cavity mode coupling from the hybrid plasmonic microcavity are also measured. This work shows that by introducing an ...


Electron Spectrum Of The Dragonfly Pulsar Wind Nebula From X-Ray To Tev, Chad Brisbois, V. Joshi Jan 2019

Electron Spectrum Of The Dragonfly Pulsar Wind Nebula From X-Ray To Tev, Chad Brisbois, V. Joshi

Michigan Tech Publications

The Dragonfly nebula is a Vela-like Pulsar Wind Nebula (PWN) in the Cygnus region powered by the spin down of PSR J2021+3651. In X-rays, the inner nebula is a few arcseconds across, whereas at TeV energies VERITAS and HAWC has observed extended emission much larger than the extension in X-rays. The TeV gamma-ray source HAWC J2019+368 was originally discovered in 2007 by the Milagro Observatory and has been associated with this pulsar. Recent work has shown hints of energy dependent morphology for the source at TeV energies, supporting the interpretation of the gamma-ray emission being due to Inverse ...


Testing The Limits Of Particle Acceleration In Cygnus Ob2 With Hawc, Binita Hona, H. Fleischhack, Petra Huentemeyer Jan 2019

Testing The Limits Of Particle Acceleration In Cygnus Ob2 With Hawc, Binita Hona, H. Fleischhack, Petra Huentemeyer

Michigan Tech Publications

Star forming regions (SFRs) have been postulated as possible sources of cosmic rays (CRs) in our galaxy. One example of a gamma-ray source associated with an SFR is the Fermi-LAT cocoon, an extended region of gamma-ray emission in the Cygnus X region and attributed to a possible superbubble with freshly accelerated CRs. Because the emission region is surrounded by ionization fronts, it has been named the Cygnus cocoon. CRs in the cocoon could have originated in the OB2 association and been accelerated at the interaction sites of stellar winds of massive O type stars. So far, there is no clear ...


Physical Foundations Of Biological Mentality, Kenneth Augustyn Jan 2019

Physical Foundations Of Biological Mentality, Kenneth Augustyn

Michigan Tech Publications

Dualism struggles to connect two layers: the conscious mind and the physical workings of matter. It ignores a vast middle layer between the two, a layer that is beneath consciousness yet above known physical law. This middle layer is trans-robotic mentality, a means discovered by Nature to transcend robotic mentality. This middle layer evolved over billions of years before consciousness emerged from it, assuming more and more functions critical to survival as species evolved. Consciousness eventually emerged from trans-robotic mentality (not from robotic mentality), first intermittently then later more-or-less continuously. But there is no direct link between consciousness and matter ...


Introduction To The Second Special Issue On Biological Mentality, Kenneth Augustyn Jan 2019

Introduction To The Second Special Issue On Biological Mentality, Kenneth Augustyn

Michigan Tech Publications

No abstract provided.


First Galactic Survey Of Energy-Dependent Diffusion By Hawc, Chad Brisbois, Hao Zhou Jan 2019

First Galactic Survey Of Energy-Dependent Diffusion By Hawc, Chad Brisbois, Hao Zhou

Michigan Tech Publications

HAWC’s wide field-of-view enables unbiased observations of much of the galaxy, allowing for analysis of many candidate sources in the HAWC dataset. Recent work has allowed HAWC to start investigating electron diffusion around pulsars at TeV energies. Surveying electron diffusion at TeV energies along the galactic plane is a unique capability of HAWC that allows us to examine the sources of electrons in our galaxy and constrain the energy dependence of the diffusion mech-anism. HAWC has already applied this model to the Geminga and Monogem pulsars. This work will expand the study to include multiple sources associated with pulsars ...


Effect Of Zno Electron Extraction Layer On Charge Recombination And Collection Properties In Organic Solar Cells, Weixia Lan, Yang Liu, Department Of Physics, Research Centre Of Excellence For Organic Electronics, And Institute Of Advanced Materials, Hong Kong Baptist University, Hong Kong, Bin Xu, Huayan Pu, Bin Wei, Wenjing Tian, Furong Zhu Jan 2019

Effect Of Zno Electron Extraction Layer On Charge Recombination And Collection Properties In Organic Solar Cells, Weixia Lan, Yang Liu, Department Of Physics, Research Centre Of Excellence For Organic Electronics, And Institute Of Advanced Materials, Hong Kong Baptist University, Hong Kong, Bin Xu, Huayan Pu, Bin Wei, Wenjing Tian, Furong Zhu

HKBU Staff Publication

The effect of zinc oxide (ZnO) electron extraction layer (EEL) on charge recombination and collection properties in bulk-heterojunction (BHJ) organic solar cells (OSCs), based on poly[[4,8-bis[(2-ethylhexyl)oxy] benzo [1,2-b:4,5-b'] dithiophene-2,6- diyl] [3-fluoro-2-[(2- ethylhexyl)carbonyl] thieno [3,4-b] thiophenediyl]] (PTB7):3'H-Cyclopropa[8,25] [5,6]fullerene-C70-D5h(6)-3'- butanoicacid, 3'-phenyl-, methyl ester (PC70BM) blend system, has been analyzed using the transient photo-current (TPC) and photo-induced charge extraction by linearly increasing voltage (photo-CELIV) measurements. The TPC and photo-CELIV results indicate that the trap-limited bimolecular recombination can be strongly suppressed by interposing a ...


Panchromatic Ternary Organic Solar Cells With Porphyrin Dimers And Absorption-Complementary Benzodithiophene-Based Small Molecules, Venkatesh Piradi, Xiaopeng Xu, Zaiyu Wang, Jazib Ali, Qiang Peng, Feng Liu, Xunjin Zhu Jan 2019

Panchromatic Ternary Organic Solar Cells With Porphyrin Dimers And Absorption-Complementary Benzodithiophene-Based Small Molecules, Venkatesh Piradi, Xiaopeng Xu, Zaiyu Wang, Jazib Ali, Qiang Peng, Feng Liu, Xunjin Zhu

HKBU Staff Publication

Diketopyrrolopyrrole–ethynylene-bridged porphyrin dimers are capped with electron-deficient 3-ethylrhodanine (A2) via a π-bridge of phenylene ethynylene, affording two new acceptor–donor–acceptor structural porphyrin dimers (DPP-2TTP and DPP-2TP) with strong absorption in ranges of 400–550 nm (Soret bands) and 700–900 nm (Q bands). Their intrinsic absorption deficiency between the Soret and Q bands could be perfectly compensated by a wide-bandgap small molecule DR3TBDTTF (D*) with absorption at 500–700 nm. Impressively, the optimal ternary device based on the blend films of DPP-2TPP, DR3TBDTTF (20 wt %), and PC71BM shows a PCE of 11.15%, whereas the ...


Towards All-Solution-Processed Top-Illuminated Flexible Organic Solar Cells Using Ultrathin Ag-Modified Graphite-Coated Poly(Ethylene Terephthalate) Substrates, Shuanglong Wang, Yi Zhao, Hong Lian, Cuiyun Peng, Xuyong Yang, Yulai Gao, Yan Peng, Weixia Lan, Omar Ibrahim Elmi, Didier Stiévenard, Bin Wei, Furong Zhu, Tao Xu Jan 2019

Towards All-Solution-Processed Top-Illuminated Flexible Organic Solar Cells Using Ultrathin Ag-Modified Graphite-Coated Poly(Ethylene Terephthalate) Substrates, Shuanglong Wang, Yi Zhao, Hong Lian, Cuiyun Peng, Xuyong Yang, Yulai Gao, Yan Peng, Weixia Lan, Omar Ibrahim Elmi, Didier Stiévenard, Bin Wei, Furong Zhu, Tao Xu

HKBU Staff Publication

All-solution-processed flexible organic solar cells (FOSCs) with high power conversion efficiency (PCE) are the prerequisite for application in low-cost, large-area, flexible, photovoltaic devices. In this work, high-performance, top-illuminated FOSCs using ultrathin Ag-modified graphite-coated poly(ethylene terephthalate) (PET) substrates are demonstrated. The ultrathin Agmodified graphite/PET substrates have excellent electric conductivity, mechanical flexibility, and easy processability for FOSCs. A PCE of 5.31% for FOSCs, based on the blend system poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl) benzo [1,2-b:4,5-b′]dith-iophene-co-3-fluorothieno[3,4- b]thiophene-2-carboxylate]: [6,6]-phenyl-C7l-but-yric acid methyl ester, having a bilayer of MoOx/Ag upper transparent anode ...


Sodium Citrate Modified-Pedot:Pss Hole Transporting Layer For Performance Enhancement Of Inverted Planar Perovskite Solar Cells, Ali Asgher Syed, Chung Yan Poon, Hung Wing Li, Furong Zhu Jan 2019

Sodium Citrate Modified-Pedot:Pss Hole Transporting Layer For Performance Enhancement Of Inverted Planar Perovskite Solar Cells, Ali Asgher Syed, Chung Yan Poon, Hung Wing Li, Furong Zhu

HKBU Staff Publication

The properties of the hole transporting layer (HTL) play an important role in determining the performance of the inverted planar perovskite solar cells (PSCs). High performing methylammonium lead iodide PSCs were demonstrated through controlled growth of the perovskite layer and suppression of charge recombination at the perovskite/electrode interfaces. In this work, the effect of sodium citrate modified poly (3,4-ethylenedioxythiophene): poly (4- styrenesulfonate) (PEDOT:PSS) HTL on the growth of the perovskite active layer, charge extraction properties and hence the performance of the PSCs was investigated. Power conversion efficiency (PCE) of >11.50% was achieved for low-processing temperature solution-processable ...


Advances In Solution-Processable Near-Infrared Phototransistors, Ning Li, Zhaojue Lan, Linfeng Cai, Furong Zhu Jan 2019

Advances In Solution-Processable Near-Infrared Phototransistors, Ning Li, Zhaojue Lan, Linfeng Cai, Furong Zhu

HKBU Staff Publication

Solution processable near infrared (NIR) photodetectors provide a promising alternative due to their low cost, flexible design, adaptability to various fabrications, and large area manufacturability, removed the limitations of traditional wafer-based inorganic semiconductor techniques. There are two typical solution-processable NIR photodetectors: photodiodes (PDs) and phototransistors (PTs). PDs have a stack of functional layers sandwiched between an anode and a cathode. The external quantum efficiency (EQE) of the NIR PDs cannot be higher than 100%. In comparison, NIR PTs are three-terminal devices with an ultra-low noise current, providing high-sensitivity and tunable gain with an EQE in excess of 100%, achieved by ...


Studies Of The Time Structure Of Extended Air Showers For Direction Reconstruction With The Hawc Outrigger Array, Dezhi Huang Jan 2019

Studies Of The Time Structure Of Extended Air Showers For Direction Reconstruction With The Hawc Outrigger Array, Dezhi Huang

Michigan Tech Publications

The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a ground-based air shower array designed to detect Cherenkov light produced in water by secondary particles from atmospheric air showers. In order to improve the sensitivity at the highest energies, especially for the shower cores falling outside the main array, 345 smaller Water Cherenkov Detectors (WCDs) were installed around the main array, the outrigger array. This extension increased the instrumented area of HAWC by a factor of four. With the increased size of the array, and the ability to detect shower particles further away from the core, understanding of the time ...


Revisiting The Paleomagnetism Of The Neoarchean Uauá Mafic Dyke Swarm, Brazil: Implications For Archean Supercratons, J. Salminen, E. P. Oliveira, Elisa J. Piispa, Aleksey Smirnov, R. I. F. Trindade Dec 2018

Revisiting The Paleomagnetism Of The Neoarchean Uauá Mafic Dyke Swarm, Brazil: Implications For Archean Supercratons, J. Salminen, E. P. Oliveira, Elisa J. Piispa, Aleksey Smirnov, R. I. F. Trindade

Michigan Tech Publications

The original connections of Archean cratons are becoming traceable due to an increasing amount of paleomagnetic data and refined magmatic barcodes. The Uauá block of the northern São Francisco craton may represent a fragment of a major Archean craton. Here, we report new paleomagnetic data from the 2.62 Ga Uauá tholeiitic mafic dyke swarm of the Uauá block in the northern São Francisco craton, Eastern Brazil. Our paleomagnetic results confirm the earlier results for these units, but our interpretation differs. We suggest that the obtained characteristic remanent magnetization for the 2.62 Ga swarm is of primary origin, supported ...


Nir To Visible Light Upconversion Devices Comprising An Nir Charge Generation Layer And A Perovskite Emitter, Ning Li, Ying Suet Lau, Xiao Zuo, Liming Ding, Furong Zhu Dec 2018

Nir To Visible Light Upconversion Devices Comprising An Nir Charge Generation Layer And A Perovskite Emitter, Ning Li, Ying Suet Lau, Xiao Zuo, Liming Ding, Furong Zhu

HKBU Staff Publication

Near‐infrared (NIR) to visible light upconversion is of significant importance in many applications, including thermal imaging, bioimaging, night vision, and wellness monitoring. Here, the effort to develop a high‐performing NIR to saturated green light upconversion device comprising a front solution‐processable organic bulk heterojunction NIR charge generation layer (CGL) and an upper CsPbBr3 perovskite light‐emitting diode (LED) unit is reported. The NIR CGL, based on a blend of the NIR‐sensitive donor polymer and a nonfullerene acceptor, enables an efficient hole injection in the CsPbBr3 LED in the presence of the NIR light and also serves as ...


How Does The Flexibility Of Molecules Affect The Performance Of Molecular Rotors?, Rundong Zhao, Fei Qi, Rui-Qin Zhang, Michel A. Van Hove Nov 2018

How Does The Flexibility Of Molecules Affect The Performance Of Molecular Rotors?, Rundong Zhao, Fei Qi, Rui-Qin Zhang, Michel A. Van Hove

HKBU Staff Publication

In research on molecular machines, the flexibility of the molecules has been shown to significantly affect the performance of such “soft” machines and thus lead to unexpected phenomena that differ from rigid machines in the macroscopic world. Taking several typical rotational molecules as examples, we examine how the deformation of the molecule (commonly caused by curving parts of a molecule due to its interaction with other molecules) affects the effectiveness of a molecular machine system, such as a chain of molecular gears. From the viewpoint of quantum chemistry and classical mechanics, we introduce a torque analysis strategy to quantitatively analyze ...


Scale Dependence Of Cloud Microphysical Response To Turbulent Entrainment And Mixing, Bipin Kumar, Paul Gotzfried, Neethl Suresh, Jörg Schumacher, Raymond Shaw Oct 2018

Scale Dependence Of Cloud Microphysical Response To Turbulent Entrainment And Mixing, Bipin Kumar, Paul Gotzfried, Neethl Suresh, Jörg Schumacher, Raymond Shaw

Michigan Tech Publications

The dynamics and lifetime of atmospheric clouds are tightly coupled to entrainment and turbulent mixing. This paper presents direct numerical simulations of turbulent mixing followed by droplet evaporation at the cloud‐clear air interface in a meter‐sized volume, with an ensemble of up to almost half a billion individual cloud water droplets. The dependence of the mixing process on domain size reveals that inhomogeneous mixing becomes increasingly important as the domain size is increased. The shape of the droplet size distribution varies strongly with spatial scale, with the appearance of a pronounced negative exponential tail. The increase of relative ...