- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Performance improvement in photosensitive organic field effect transistor by using multi-layer structure
摘要： In this study, a new approach was introduced for Photo-OFETs as a multi-layer structure. Poly(3-hexylthiophene-2,5-diyl) regioregular (P3HT) and Copper(II) phthalocyanine (CuPc) thin films were used as two different active photo-absorber layers in the same device structure. Poly(methyl methacrylate) (PMMA) was used as a dielectric layer and all devices were fabricated with a top-gate bottom-contact configuration. In order to investigate the effect of the location of each layer on the Photoresponsive organic field-effect transistors (Photo-OFET) performance, five different devices in various structures were produced and analyzed. Surface properties of active layers have been investigated via Atomic Force Microscopy (AFM) and effects of surface roughness on device performance have been discussed. P3HT/CuPc/P3HT multi-layered structure exhibited the best performance in terms of photoresposivity(as 45 mA/W) and photosensitivity (~ 2x103). Photo-OFET based on a multi-layer structure demonstrated superior performance with wider absorbance spectrum region compared to conventional single component devices of P3HT or CuPc. The proposed multi-layer structure can be a model to improve the realization of high performance Photo-OFETs.
关键词： Photoresponsive organic field-effect transistors,Organic field effect transistors,Multilayer structure,Poly(3-hexylthiophene),Photosensitivity,Poly(methyl methacrylate)
更新于2025-09-23 15:23:52
-
Cholesterol Functionalization of Gold Nanoparticles Enhances Photo-Activation of Neural Activity
摘要： Gold nanoparticles (AuNPs) attached to the extracellular leaflet of the plasma membrane of neurons can enable the generation of action potentials (APs) in response to brief pulses of light. Recently described techniques to stably bind AuNP bioconjugates directly to membrane proteins (ion channels) in neurons enable robust AP generation mediated by the photoexcited conjugate. However, a strategy that binds the AuNP to the plasma membrane in a non-protein-specific manner could represent a simple, single-step means of establishing light-responsiveness in multiple types of excitable neurons contained in the same tissue. Based on the ability of cholesterol to insert into the plasma membrane, here we test whether AuNP functionalization with linear dihydrolipoic acid-poly(ethylene) glycol (DHLA-PEG) chains that are distally terminated with cholesterol (AuNP-PEG-Chol) can enable light-induced AP generation in neurons. Dorsal root ganglion (DRG) neurons of rat were labelled with 20 nm diameter spherical AuNP-PEG-Chol conjugates wherein ~30% of the surface ligands (DHLA-PEG-COOH) were conjugated to PEG-Chol. Voltage recordings under current-clamp conditions showed that DRG neurons labeled in this manner exhibited a capacity for AP generation in response to microsecond and millisecond pulses of 532 nm light, a property attributable to the close tethering of AuNP-PEG-Chol conjugates to the plasma membrane facilitated by the cholesterol moiety. Light-induced AP and subthreshold depolarizing responses of the DRG neurons were similar to those previously described for AuNP conjugates targeted to channel proteins using large, multicomponent immunoconjugates. This likely reflected the AuNP-PEG-Chol’s ability, upon plasmonic light absorption and resultant slight and rapid heating of the plasma membrane, to induce a concomitant transmembrane depolarizing capacitive current. Notably, AuNP-PEG-Chol delivered to DRG neurons by inclusion in the buffer contained in the recording pipette/electrode enabled similar light-responsiveness, consistent with the activity of AuNP-PEG-Chol bound to the inner (cytofacial) leaflet of the plasma membrane. Our results demonstrate the ability of AuNP-PEG-Chol conjugates to confer timely stable and direct responsiveness to light in neurons. Further, this strategy represents a general approach for establishing excitable cell photosensitivity that could be of substantial advantage for exploring a given tissue’s suitability for AuNP-mediated photo-control of neural activity.
关键词： nanoparticle functionalization,cholesterol,action potential,neural photo-activation,optocapacitance,gold nanoparticles,photosensitivity,dorsal root ganglion cell
更新于2025-09-23 15:23:52
-
"Two-in-One" Strategy of o-Amino and Aromatic Nitrogen in Biomimetic Metal-Organic Frameworks for Efficient CO2 Photoconversion
摘要： Visible-light driven photoconversion of CO2 into energy carriers is highly important to the natural carbon balance and sustainable development. Herein, we demonstrate the biological nucleobase adenine-dependent CO2 photoreduction performance in green biomimetic metal-organic frameworks. Photocatalytic results indicate that AD-MOF-2 exhibited a very high HCOOH production rate of 443.2 μmol g-1 h-1 in pure aqueous solution, which is more than two times higher than that of AD-MOF-1 (179.0 μmol hour?1 g?1) in acetonitrile solution. Significantly, experimental and theoretical evidences reveal that CO2 photoreduction reaction mainly takes place on biological adenine molecules by unique o-amino assisted active aromatic nitrogen atom rather than traditional metal center. This work not only serves as an important case study for the development of green biomimetic photocatalysts used for artificial photosynthesis, but also proposes a new catalytic strategy for efficient CO2 photoconversion.
关键词： photosensitivity,hydrophobicity,biomimetic catalysis,green MOFs,artificial photosynthesis
更新于2025-09-23 15:22:29
-
[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Photosensitivity of single silicon high-aspect-ratio tips with different doping levels
摘要： Photosensitivity of single lightly p-doped, highly p-doped, with an integrated p/n junction and intrinsic high-aspect-ratio (HAR) silicon tips was investigated in an ultra-high vacuum environment. The current-voltage characteristics (I-V) of the lightly doped p-type HAR tips showed a characteristic current saturation at around 10-12 nA, whereas the HAR Si tips with p/n junction showed similar saturation phenomena, however, at much smaller current values starting at ~20- 30 pA. Optical switching under a halogen lamp illumination resulted in at least 2-4 times higher saturation currents and showed a linear dependence between the illumination power and the FE current, for both types of structures. In case of the highly p-doped HAR tips optical current switching effects, i. e. current saturation, were observed at rather low current levels 1-2 pA. Intrinsic HAR Si-tips showed relative unstable field emission behavior without a clear evidence of the photosensitivity.
关键词： photosensitivity,Si p/n junction,p-type Si,field emission
更新于2025-09-23 15:21:21
-
Two cases of photosensitive seizure induced by barcode readers with red flashing lights; バーコードリーダーの赤色点滅光により誘発された光感受性発作の2例;
摘要： The patient in Case 1 was a 25-year-old female nurse. While she was working at a day-care, she fell down shortly after using a barcode reader. This was followed by a tonic-clonic seizure. The seizure spontaneously stopped after approximately 5 minutes. However, consciousness impairment continued for about 30 minutes. The patient in Case 2 was a 30-year-old female nurse. During the night shift at her workplace, she found it impossible to stand up after staring at the red flashing lights from a barcode reader. The patient was also disoriented, as indicated by her inability to recall her colleague’s name. The patient’s condition gradually improved and she became fully conscious soon after the episode. We believe that the barcode reader led to photosensitivity in both cases. Barcode readers that emit red flashing lights are thought to have a high potential for triggering photosensitivity. A person is highly likely to display photosensitivity while using the device in a hospital ward. Therefore, special attention is required to avoid photosensitive seizures induced by barcode readers with red flashing lights.
关键词： tonic-clonic seizure,photoparoxysmal response,disorientation,photosensitivity,consciousness disturbance
更新于2025-09-23 15:21:21
-
Photo-induced effects in organic thin film transistors based on dinaphtho [2,3-b:2′,3′-f] Thieno[3,2-b′] thiophene (DNTT)
摘要： We have investigated the photoresponse of organic thin film transistors (OTFTs) based on evaporated films of dinaphtho [2,3-b:2',3'-f] thieno[3,2-b'] thiophene (DNNT) as the active semiconductor and spin-coated polystyrene as the gate insulator. Both during illumination and in subsequent measurements in the dark after long periods under illumination, transfer characteristics shift to more positive gate voltages. The greatest photoresponse was achieved at 460 nm, near the absorption maximum of DNTT. The maximum photosensitivity and photoresponsivity measured were ~104 and 1.6 A/W respectively. The latter is the highest reported for an organic semiconductor on a polymeric gate insulator and by suitable adjustments to device geometry could be increased to match the highest reported, ~105 A/W, for organic semiconductors. Weaker responses were also obtained when exposed to light from the long-wavelength tail in the absorption spectrum. At these longer wavelengths, the response arises entirely from a shift in flatband voltage caused by deep interface trapping of photo-generated electrons. At 460 nm, however, the positive shift, D VON, in turn-on voltage is much greater than D VT suggesting that ~3.5 x 1011 electrons/cm2 are trapped at the interface at the start of the gate voltage sweep, but ~60% are neutralised by holes from the channel as the device begins to turn on. While the resulting change in subthreshold slope could be interpreted as a change in the density of states (DoS) in the DNTT, this is discounted. Gate bias stress measurements made under illumination, reveal that positive bias enhances interface electron trapping while negative bias reduces the effect owing to the simultaneous trapping of holes from the accumulation channel.
关键词： OTFT,DNTT,Interface States,Photosensitivity
更新于2025-09-23 15:21:01
-
Morphology Effect of 1D ZnO Nanostructures Designed by Hydrothermal and Thermal Annealing for Fast Ultraviolet Photodetector Applications
摘要： Zinc oxide (ZnO) nanorods were grown on a ZnO seed layer using the hydrothermal method and subsequently annealed at temperatures of 400–800 °C. The ZnO nanorods annealed at 400 °C exhibited morphology similar to that of the unannealed ZnO nanorods. However, the tips of the ZnO nanorods gradually became rounded and their density and diameter increased with an increase in the annealing temperature. The intensity of the near-band-edge emission increased gradually with an increase in the annealing temperature from 400 to 600 °C but decreased sharply in the case of the nanorods annealed at 800 °C. With respect to the deep-level emissions, broad yellow, orange, and green emissions were observed. Further, the low-temperature photoluminescence spectrum measured at 12 K of the ZnO nanorods annealed at 600 °C contained a donor-bound exciton emission, as well as emissions related to the donor-acceptor pair transition and the first-order and second-order longitudinal optical phonon replicas of the donor-acceptor pair transition. Finally, with respect to the photoresponse, the dark current and photocurrent of the nanorods decreased and their photosensitivity increased with the increase in the annealing temperature.
关键词： Ultraviolet photodetector,Zinc oxide,Photosensitivity,Photoluminescence,Hydrothermal method
更新于2025-09-23 15:19:57
-
Defect Formation in Ion-Implanted Si - Approach to Controlled Semiconductor Optical Properties
摘要： For specific modification of the fundamental optical and photoelectrical properties of silicon transparent for wavelengths beyond 1.1μm, boron ions have been implanted into n-type wafers at doses of 1 х 1013 cm-2–1 х 1015 cm-2 followed by annealing at 900 °C and 1000 °C (20 min). The IR reflection spectra, Raman spectroscopy and scanning electron microscopy data have been compared with the photosensitivity spectra (1.4–2.2 μm) and with the integrated photoresponse in the IR (1.0–4.1 μm) and UV (0.25–0.4 μm) regions. These studies allow for materials engineering to obtain new data on the influence of defect formation on the optical properties of the material and to evaluate the technological conditions for practical application of the modified material.
关键词： Boron ion implanted silicon,IR and UV photosensitivity,IR reflection spectra,p-n structures,extended defects,Raman-spectroscopy
更新于2025-09-16 10:30:52
-
Influence of 2-Amino-4-methylpyridine and 2-Aminopyrimidine Ligands on the Malonic Acid-Cu(II) System: Insights through Supramolecular Interactions and Photoresponse Properties
摘要： Two Cu(II)-malonate complexes with 2-amino-4-methylpyridine (complex 1) and 2-aminopyrimidine (complex 2) auxiliary ligands were synthesized, and their single-crystal X-ray diffraction structures were established. Change in the auxiliary ligand exhibits substantial structural variation in the present complexes. Complex 1 shows a one-dimensional anionic copper-malonate moiety connected by the malonate bridge, whereas complex 2 is a mononuclear one. For both the complexes, auxiliary ligands are attached with the Cu-malonate moiety through various noncovalent interactions. Optical band gap, electrical conductivity, and photosensitivity of complexes 1 and 2 were measured, but the values of electrical parameters of the complexes significantly differ from each other. However, the magnitudes of electrical parameters increase several times for both the complexes when they are exposed under visible light, though the values of light sensing parameters of complex 1 were found to be higher than those of complex 2. Density functional theory calculations for complex 1 were carried out to support the experimental result.
关键词： 2-aminopyrimidine,electrical conductivity,Cu(II)-malonate complexes,density functional theory,2-amino-4-methylpyridine,optical band gap,noncovalent interactions,photosensitivity
更新于2025-09-16 10:30:52
-
Safety of Combination Laser or Intense Pulsed Light Therapies and Doxycycline for the Treatment of Rosacea
摘要： BACKGROUND Current treatment options for rosacea include topical agents, oral therapies, phototherapy using lasers, or intense pulsed light (IPL). Combination therapy for rosacea often yields better results than monotherapy. The safety of laser/light treatments in combination with systemic doxycycline has been questioned because of the theoretical risk of photosensitivity. OBJECTIVE The purpose of this study was to assess the incidence of phototoxicity or photosensitivity in rosacea patients receiving concomitant laser or light treatments and systemic doxycycline. METHODS Treatment records of 36 patients receiving laser/light treatments while also being treated with standard dose or anti-inflammatory dose of doxycycline were retrospectively reviewed. RESULTS No adverse reactions related to doxycycline combined with laser/light therapy were reported. Specifically, no photosensitivity or sensitivity to wavelengths in the pulsed dye laser (PDL), or IPL range was observed in this cohort. All patients achieved some degree of clearance. CONCLUSION The results of this retrospective study demonstrate that doxycycline used in conjunction with laser or nonlaser light therapy is a valid combination therapy for improving signs and symptoms of rosacea. No photosensitivity reactions were observed to commonly used IPL or PDL devices.
关键词： rosacea,intense pulsed light,doxycycline,photosensitivity,laser therapy
更新于2025-09-12 10:27:22