5 research outputs found
Self-Powered, High-Speed and Visible–Near Infrared Response of MoO<sub>3–<i>x</i></sub>/n-Si Heterojunction Photodetector with Enhanced Performance by Interfacial Engineering
Photodetectors with a wide spectrum
response are important components for sensing, imaging, and other
optoelectronic applications. A molybdenum oxide (MoO<sub>3–<i>x</i></sub>)/Si heterojunction has been applied as solar cells
with great success, but its potential in photodetectors has not been
explored yet. Herein, a self-powered, high-speed heterojunction photodetector
fabricated by coating an n-type Si hierarchical structure with an
ultrathin hole-selective layer of molybdenum oxide (MoO<sub>3–<i>x</i></sub>) is first investigated. Excellent and stable photoresponse
performance is obtained by using a methyl group passivated interface.
The heterojunction photodetector demonstrated high sensitivity to
a wide spectrum from 300 to 1100 nm. The self-powered photodetector
shows a high detectivity of (∼6.29 × 10<sup>12</sup> cmHz<sup>1/2</sup> W<sup>–1</sup>) and fast response time (1.0 μs).
The excellent photodetecting performance is attributed to the enhanced
interfacial barrier height and three-dimensional geometry of Si nanostructures,
which is beneficial for efficient photocarrier collection and transportation.
Finally, our devices show excellent long-term stability in air for
6 months with negligible performance degradation. The thermal evaporation
method for large-scale fabrication of MoO<sub>3–<i>x</i></sub>/n-Si photodetectors makes it suitable for self-powered, multispectral,
and high-speed response photodetecting applications
Interface Engineering To Boost Photoresponse Performance of Self-Powered, Broad-Bandwidth PEDOT:PSS/Si Heterojunction Photodetector
Organic–inorganic
hybrid heterojunctions are poised to push toward novel optoelectronics
applications, such as photodetectors, but significant challenges complicating
practical use remain. Although all organic based photodetectors have
been reported with great success, their potential in high-speed, broadband,
self-powered photodetectors have not been fully explored. Herein,
a self-powered, broad bandwidth of photodetector based on PEDOT:PSS/Si
heterojunction is built by a facial low temperature spin-coating method.
By interface engineering of heterojunction with optimal band alignment
and heteromicrostructures, enhanced photoresponse performances are
obtained. The bandwidth of the hybrid photodetector could be broadened
by 10 kHz after interfacial passivation by a methyl group. Further
manipulating the geometrical structure of the hybrid heterojunction
with silicon nanowire, a broad spectrum response from 300 to 1100
nm, with bandwidth as high as 40.6 kHz, fast response speed of 2.03 μs
and high detection of 4.1 × 10<sup>11</sup> Jones under zero
bias was achieved. Meanwhile, the close dependence between the photoresponse
performance of heterojunctions and Si nanowire length is observed
in the top-coverage configuration. Finally, a coverage effects model
is proposed based on the competition of Si bulk and surface recombination,
which is also confirmed by the designed bottom-coverage experiment.
The mechanisms behind the enhanced photoresponse of the hybrid photodetector
is attributed to the optimum band alignment, as well as the optimum
balance of carrier dissociation and recombination of heterojunction.
The scalable and low temperature method would be of great convenience
for large-scale fabrication of the PEDOT:PSS/Si hybrid photodetector
Electrochromic Asymmetric Supercapacitor Windows Enable Direct Determination of Energy Status by the Naked Eye
Because
of the popularity of smart electronics, multifunctional energy storage
devices, especially electrochromic supercapacitors (SCs), have attracted
tremendous research interest. Herein, a solid-state electrochromic
asymmetric SC (ASC) window is designed and fabricated by introducing
WO<sub>3</sub> and polyaniline as the negative and positive electrodes,
respectively. The two complementary materials contribute to the outstanding
electrochemical and electrochromic performances of the fabricated
device. With an operating voltage window of 1.4 V and an areal capacitance
of 28.3 mF cm<sup>–2</sup>, the electrochromic devices show
a high energy density of 7.7 × 10<sup>–3</sup> mW h cm<sup>–2</sup>. Meanwhile, they exhibit an obvious and reversible
color transition between light green (uncharged state) and dark blue
(charged state), with an optical transmittance change between 55 and
12% at a wavelength of 633 nm. Hence, the energy storage level of
the ASC is directly related to its color and can be determined by
the naked eye, which means it can be incorporated with other energy
cells to visual display their energy status. Particularly, a self-powered
and color-indicated system is achieved by combining the smart windows
with commercial solar cell panels. We believe that the novel electrochromic
ASC windows will have great potential application for both smart electronics
and smart buildings
Tailorable and Wearable Textile Devices for Solar Energy Harvesting and Simultaneous Storage
The pursuit of harmonic combination
of technology and fashion intrinsically
points to the development of smart garments. Herein, we present an
all-solid tailorable energy textile possessing integrated function
of simultaneous solar energy harvesting and storage, and we call it
tailorable textile device. Our technique makes it possible to tailor
the multifunctional textile into any designed shape without impairing
its performance and produce stylish smart energy garments for wearable
self-powering system with enhanced user experience and more room for
fashion design. The “threads” (fiber electrodes) featuring
tailorability and knittability can be large-scale fabricated and then
woven into energy textiles. The fiber supercapacitor with merits of
tailorability, ultrafast charging capability, and ultrahigh bending-resistance
is used as the energy storage module, while an all-solid dye-sensitized
solar cell textile is used as the solar energy harvesting module.
Our textile sample can be fully charged to 1.2 V in 17 s by self-harvesting
solar energy and fully discharged in 78 s at a discharge current density
of 0.1 mA
DataSheet1_Asymmetries and relationships between muscle strength, proprioception, biomechanics, and postural stability in patients with unilateral knee osteoarthritis.docx
Background: The pathological mechanism of knee osteoarthritis (KOA) is unknown. KOA degeneration may be associated with changes in muscle strength, proprioception, biomechanics, and postural stability.Objective: This study aimed to assess asymmetries in muscle strength, proprioception, biomechanics, and postural stability of bilateral lower limbs in patients with unilateral KOA and healthy controls and analyze correlations between KOA and these parameters.Methods: A total of 50 patients with unilateral KOA (age range: 50-70) and 50 healthy subjects were recruited as study participants (age range: 50-70). Muscle strength, proprioception, femorotibial angle (FTA), femoral condylar–tibial plateau angle (FCTP), average trajectory error (ATE), and center of pressure (COP) sways areas were accessed in study participants, and the correlation between these variables was investigated.Results: In patients with unilateral KOA, lower limb muscle strength was significantly lower on the symptomatic side than on the asymptomatic side (p 0.05). Patients with unilateral KOA had lower muscle strength than healthy controls (p 0.05).Conclusion: In patients with unilateral KOA, muscle strength, proprioception, biomechanics, and postural stability of bilateral limbs are asymmetrical in unilateral KOA patients. Muscle strength, proprioception, and postural stability are significantly associated variables, and changes in these variables should be considered in KOA prevention and rehabilitation.</p