28 research outputs found
Graphene Oxide-Based Carbon Interconnecting Layer for Polymer Tandem Solar Cells
Tandem
polymer solar cells (PSCs), consisting of more than one
(normally two) subcells connected by a charge recombination layer
(i.e., interconnecting layer), hold great promise for enhancing the
performance of PSCs. For an ideal tandem solar cell, the open circuit
voltage (<i>V</i><sub>oc</sub>) equals to the sum of those
of the subcells while keeping the short circuit current the same as
the lower one, leading to an increased overall power conversion efficiency.
The interconnecting layer plays an important role in regulating the
tandem device performance. Here, we report that graphene oxide (GO)/GO-Cs
(cesium neutralized GO) bilayer modified with ultrathin Al and MoO<sub>3</sub> can act as an efficient interconnecting layer in tandem PSCs
to achieve a significantly increased <i>V</i><sub>oc</sub>, reaching almost 100% of the sum of the subcell <i>V</i><sub>oc</sub>s under standard AM 1.5 conditions
Auger Electron Spectroscopy Analysis of the Thermally Induced Degradation of MAPbI<sub>3</sub> Perovskite Films
Organometal halide
perovskites are highly promising materials for
photovoltaic applications due to the rapid growth of power conversion
efficiency in recent years. However, thermal stability is still a
major hurdle for perovskite solar cells toward commercialization.
Herein, we first explore the slow thermal response of the CH3NH3PbI3 perovskite crystal investigated via
Auger electron spectroscopy (AES). AES image mapping directly observes
the evolution of morphology and elemental distribution over time.
The AES small spot analysis demonstrates the precise initial degradation
position of perovskite with both information regarding physical changes
in crystals and chemical changes in elemental bonding at the nanometer
scale. X-ray photoelectron spectroscopy (XPS) was used to confirm
the surface chemical bonding and composition of the perovskite crystals.
This work provides the first insights into the physical and chemical
changes of perovskites investigated by AES upon long-term exposure
to heat under ambient conditions
Photolysis of Chlorine Dioxide under UVA Irradiation: Radical Formation, Application in Treating Micropollutants, Formation of Disinfection Byproducts, and Toxicity under Scenarios Relevant to Potable Reuse and Drinking Water
Conversion
of potable reuse water utilities and drinking water
utilities from a low-pressure UV/H2O2 (LPUV/H2O2) advanced oxidation process (AOP) to alternative
AOPs in which oxidants can effectively absorb photons and rapidly
generate radicals has attracted great interest. Herein, we propose
a novel UVA/ClO2 AOP for different water treatment scenarios
because of reduced photon absorption by the background matrix and
high molar absorptivity for ClO2 at UVA wavelengths. While
the photolysis of ClO2 produces •Cl +
O2 or •ClO + OÂ(3P) via distinct
product channels, we determined the parameters needed to accurately
model the loss of oxidants and the formation of byproducts and combined
a kinetic model with experimental data to determine quantum yields
(Φ). Modeling incorporating the optimized Φ simultaneously
predicted oxidant loss and the formation of major products −HOCl,
Cl–, and ClO3–. We
also systematically investigated the removal of three contaminants
exhibiting different radical reactivities, the formation of 35 regulated
and unregulated halogenated disinfection byproducts (DBPs), DBP-associated
toxicity, and N-acetylcysteine thiol reactivity in
synthetic or authentic RO permeates/surface waters treated by different
AOPs. The kinetic model developed in this study was used to optimize
operating conditions to control undesired products and improve contaminant
removal efficiency. The results indicate that UVA/ClO2 can
outperform LPUV/H2O2 in terms of electrical
energy per order of contaminant degradation, disinfection byproduct
formation, and toxicity indices
Imaging the Long Transport Lengths of Photo-generated Carriers in Oriented Perovskite Films
Organometal
halide perovskite has emerged as a promising material for solar cells
and optoelectronics. Although the long diffusion length of photogenerated
carriers is believed to be a critical factor responsible for the material’s
high efficiency in solar cells, a direct study of carrier transport
over long distances in organometal halide perovskites is still lacking.
We fabricated highly oriented crystalline CH3NH3PbI3 (MAPbI3) thin-film lateral transport devices
with long channel length (∼120 μm). By performing spatially
scanned photocurrent imaging measurements with local illumination,
we directly show that the perovskite films prepared here have very long transport lengths for photogenerated
carriers, with a minority carrier (electron) diffusion length on the
order of 10 μm. Our approach of applying scanning photocurrent
microscopy to organometal halide perovskites may be further used to
elucidate the carrier transport processes and the vastly different
carrier diffusion lengths (∼100 nm to 100 μm) in different
types of organometal halide perovskites
Table4_The association between mortality and use of Chinese herbal medicine among incident stage IV esophageal cancer patients: A retrospective cohort study with core herbs exploration.XLSX
Esophageal cancer (EC) remains a leading cause of death worldwide and in Taiwan. The prognosis of advanced-stage EC is notably poor, and the treatment options are limited. Chinese herbal medicine (CHM) has been widely used as a complementary treatment for cancer, yet the long-term effect of CHM in stage IV EC remains unclear.The multi-institutional cohort obtained from the Chang Gung research database (CGRD) was used to study the long-term outcome of CHM use among incident stage IV EC patients from 1 January 2002, to 31 December 2018. All patients were followed up to 5Â years or the occurrence of death. The overall survival (OS) and disease-specific survival rates were conducted using Kaplan-Meier estimation. Overlap weighing and landmark analysis were used to eliminate confounding and immortal time biases. Furthermore, we demonstrated the core CHMs for stage IV EC by using the Chinese herbal medicine network (CMN) analysis on prescriptions.Nine hundred eighty-five stage IV EC patients were analyzed, including 74 CHM users and 911 non-CHM users. We found the use of CHM was associated with a higher 5-year overall survival rate than CHM nonusers (the cumulative probability: 19.52% versus 6.04%, log-rank test: p The use of CHM seems safe and possibly beneficial among stage IV EC patients with a higher 5-year OS. Further clinical trials on CHM were guaranteed to explore the role of CHM in managing stage IV EC patients.</p
Table1_The association between mortality and use of Chinese herbal medicine among incident stage IV esophageal cancer patients: A retrospective cohort study with core herbs exploration.DOCX
Esophageal cancer (EC) remains a leading cause of death worldwide and in Taiwan. The prognosis of advanced-stage EC is notably poor, and the treatment options are limited. Chinese herbal medicine (CHM) has been widely used as a complementary treatment for cancer, yet the long-term effect of CHM in stage IV EC remains unclear.The multi-institutional cohort obtained from the Chang Gung research database (CGRD) was used to study the long-term outcome of CHM use among incident stage IV EC patients from 1 January 2002, to 31 December 2018. All patients were followed up to 5Â years or the occurrence of death. The overall survival (OS) and disease-specific survival rates were conducted using Kaplan-Meier estimation. Overlap weighing and landmark analysis were used to eliminate confounding and immortal time biases. Furthermore, we demonstrated the core CHMs for stage IV EC by using the Chinese herbal medicine network (CMN) analysis on prescriptions.Nine hundred eighty-five stage IV EC patients were analyzed, including 74 CHM users and 911 non-CHM users. We found the use of CHM was associated with a higher 5-year overall survival rate than CHM nonusers (the cumulative probability: 19.52% versus 6.04%, log-rank test: p The use of CHM seems safe and possibly beneficial among stage IV EC patients with a higher 5-year OS. Further clinical trials on CHM were guaranteed to explore the role of CHM in managing stage IV EC patients.</p
Table2_The association between mortality and use of Chinese herbal medicine among incident stage IV esophageal cancer patients: A retrospective cohort study with core herbs exploration.XLSX
Esophageal cancer (EC) remains a leading cause of death worldwide and in Taiwan. The prognosis of advanced-stage EC is notably poor, and the treatment options are limited. Chinese herbal medicine (CHM) has been widely used as a complementary treatment for cancer, yet the long-term effect of CHM in stage IV EC remains unclear.The multi-institutional cohort obtained from the Chang Gung research database (CGRD) was used to study the long-term outcome of CHM use among incident stage IV EC patients from 1 January 2002, to 31 December 2018. All patients were followed up to 5Â years or the occurrence of death. The overall survival (OS) and disease-specific survival rates were conducted using Kaplan-Meier estimation. Overlap weighing and landmark analysis were used to eliminate confounding and immortal time biases. Furthermore, we demonstrated the core CHMs for stage IV EC by using the Chinese herbal medicine network (CMN) analysis on prescriptions.Nine hundred eighty-five stage IV EC patients were analyzed, including 74 CHM users and 911 non-CHM users. We found the use of CHM was associated with a higher 5-year overall survival rate than CHM nonusers (the cumulative probability: 19.52% versus 6.04%, log-rank test: p The use of CHM seems safe and possibly beneficial among stage IV EC patients with a higher 5-year OS. Further clinical trials on CHM were guaranteed to explore the role of CHM in managing stage IV EC patients.</p
X-ray Photoelectron Spectrometry Depth Profiling of Organic Thin Films Using C<sub>60</sub> Sputtering
A buckminsterfullerene (C60) ion beam was used for X-ray
photoelectron spectrometry depth profiling of various
organic thin films. Specimens representing different interfaces in organic light-emitting diode devices, including
hole-conducting poly(ethylenedioxythiophene), poly(styrenesulfonic acid) (PEDOT:PSS) thin films on ITO with
and without polysilicic acid doping, light-emitting Ir-containing 4,4‘-bis(carbazol-9-yl)biphenyl (CBP) molecules on PEDOT:PSS, and electron-conducting 2,2‘,2‘ ‘(1,3,5-benzinetriyl)tris(1-phenyl-1-H-benzimidazole) (TPBi)
molecules on CBP, were studied. In all cases, a clear
multilayer structure was observed. The chemical composition and elemental state were preserved after C60+ ion
sputtering. The sputter rate was found to decrease with
sputtering time. This is due to the deposition of amorphous carbon on the surface, with the rate of implantation
highly dependent on the surface interacting with the ion
beam
Table3_The association between mortality and use of Chinese herbal medicine among incident stage IV esophageal cancer patients: A retrospective cohort study with core herbs exploration.XLSX
Esophageal cancer (EC) remains a leading cause of death worldwide and in Taiwan. The prognosis of advanced-stage EC is notably poor, and the treatment options are limited. Chinese herbal medicine (CHM) has been widely used as a complementary treatment for cancer, yet the long-term effect of CHM in stage IV EC remains unclear.The multi-institutional cohort obtained from the Chang Gung research database (CGRD) was used to study the long-term outcome of CHM use among incident stage IV EC patients from 1 January 2002, to 31 December 2018. All patients were followed up to 5Â years or the occurrence of death. The overall survival (OS) and disease-specific survival rates were conducted using Kaplan-Meier estimation. Overlap weighing and landmark analysis were used to eliminate confounding and immortal time biases. Furthermore, we demonstrated the core CHMs for stage IV EC by using the Chinese herbal medicine network (CMN) analysis on prescriptions.Nine hundred eighty-five stage IV EC patients were analyzed, including 74 CHM users and 911 non-CHM users. We found the use of CHM was associated with a higher 5-year overall survival rate than CHM nonusers (the cumulative probability: 19.52% versus 6.04%, log-rank test: p The use of CHM seems safe and possibly beneficial among stage IV EC patients with a higher 5-year OS. Further clinical trials on CHM were guaranteed to explore the role of CHM in managing stage IV EC patients.</p
Depth Profiling of Organic Films with X-ray Photoelectron Spectroscopy Using C<sub>60</sub><sup>+</sup> and Ar<sup>+</sup> Co-Sputtering
By sputtering organic films with 10 kV, 10 nA C60+ and
0.2 kV, 300 nA Ar+ ion beams concurrently and analyzing
the newly exposed surface with X-ray photoelectron
spectroscopy, organic thin-film devices including an organic light-emitting diode and a polymer solar cell with
an inverted structure are profiled. The chemical composition and the structure of each layer are preserved and
clearly observable. Although C60+ sputtering is proven to
be useful for analyzing organic thin-films, thick organic-devices cannot be profiled without the low-energy Ar+
beam co-sputtering due to the nonconstant sputtering rate
of the C60+ beam. Various combinations of ion-beam doses
are studied in this research. It is found that a high dosage
of the Ar+ beam interferes with the C60+ ion beam, and
the sputtering rate decreases with increasing the total ion
current. The results suggest that the low-energy single-atom projectile can disrupt the atom deposition from the
cluster ion beams and greatly extend the application of
the cluster ion-sputtering. By achievement of a steady
sputtering rate while minimizing the damage accumulation, this research paves the way to profiling soft matter
and organic electronics