8 research outputs found
Optical and Electronic Properties of Femtosecond Laser-Induced Sulfur-Hyperdoped Silicon N+/P Photodiodes
Impurity-mediated near-infrared (NIR) photoresponse in silicon is of great interest for photovoltaics and photodetectors. In this paper, we have fabricated a series of n+/p photodetectors with hyperdoped silicon prepared by ion-implantation and femtosecond pulsed laser. These devices showed a remarkable enhancement on absorption and photoresponse at NIR wavelengths. The device fabricated with implantation dose of 1014 ions/cm2 has exhibited the best performance. The proposed method offers an approach to fabricate low-cost broadband silicon-based photodetectors
Optical and Electronic Properties of Femtosecond Laser-Induced Sulfur-Hyperdoped Silicon N+/P Photodiodes
Abstract Impurity-mediated near-infrared (NIR) photoresponse in silicon is of great interest for photovoltaics and photodetectors. In this paper, we have fabricated a series of n+/p photodetectors with hyperdoped silicon prepared by ion-implantation and femtosecond pulsed laser. These devices showed a remarkable enhancement on absorption and photoresponse at NIR wavelengths. The device fabricated with implantation dose of 1014 ions/cm2 has exhibited the best performance. The proposed method offers an approach to fabricate low-cost broadband silicon-based photodetectors
Enhancement of Fenton processes at initial circumneutral pH for the degradation of norfloxacin with Fe@Fe 2
Enhancement of Fenton processes at initial circumneutral pH for the degradation of norfloxacin with Fe@Fe<sub>2</sub>O<sub>3</sub> core-shell nanomaterials
<p>The degradation of norfloxacin by Fenton reagent with core-shell Fe@Fe<sub>2</sub>O<sub>3</sub> nanomaterials was studied under neutral conditions in a closed batch system. Norfloxacin was significantly degraded (90%) in the Fenton system with Fe@Fe<sub>2</sub>O<sub>3</sub> in 30 min at the initial pH 7.0, but slightly degraded in Fenton system without Fe@Fe<sub>2</sub>O<sub>3</sub> under the same experimental conditions. The intermediate products were investigated by gas chromatography-mass spectrometry, and the possible Fenton oxidation pathway of norfloxacin in the presence of Fe@Fe<sub>2</sub>O<sub>3</sub> nanowires was proposed. Electron spin resonance spectroscopy was used to identify and characterize the free radicals generated, and the mechanism for norfloxacin degradation was also revealed. Finally, the reusability and the stability of Fe@Fe<sub>2</sub>O<sub>3</sub> nanomaterials were studied using x-ray diffraction and scanning electron microscope, which indicated that Fe@Fe<sub>2</sub>O<sub>3</sub> is a stable catalyst and can be used repetitively in environmental pollution control.</p
Diatomic Metasurface for Vectorial Holography
The
emerging metasurfaces with the exceptional capability of manipulating
an arbitrary wavefront have revived the holography with unprecedented
prospects. However, most of the reported metaholograms suffer from
limited polarization controls for a restrained bandwidth in addition
to their complicated meta-atom designs with spatially variant dimensions.
Here, we demonstrate a new concept of vectorial holography based on
diatomic metasurfaces consisting of metamolecules formed by two orthogonal
meta-atoms. On the basis of a simply linear relationship between phase
and polarization modulations with displacements and orientations of
identical meta-atoms, active diffraction of multiple polarization
states and reconstruction of holographic images are simultaneously
achieved, which is robust against both incident angles and wavelengths.
Leveraging this appealing feature, broadband vectorial holographic
images with spatially varying polarization states and dual-way polarization
switching functionalities have been demonstrated, suggesting a new
route to achromatic diffractive elements, polarization optics, and
ultrasecure anticounterfeiting