- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Wavelength-Conversion Material-Mediated Semiconductor Bonding for Photovoltaic Applications
摘要： Wavelength-conversion material-mediated semiconductor wafer bonding has been demonstrated, by utilizing an adhesive and viscous organic matrix embedding fluorescent particles. The wavelength-converting heterointerface can practically lead the spectral light incidence suitable for each photovoltaic material. This bonding and interfacial scheme is expected to enhance solar cell efficiency and structure flexibility by photon management and current matching among subcells. Moreover, our novel scheme provides the bonding formation and the interfacial function generation simultaneously, and therefore potentially realizes low-cost and high-throughput production processes.
关键词： fluorescent particles,wavelength-conversion,solar cell efficiency,photovoltaic applications,semiconductor bonding
更新于2025-09-23 15:19:57
-
[IEEE 2019 26th International Workshop on Active-Matrix Flatpanel Displays and Devices (AM-FPD) - Kyoto, Japan (2019.7.2-2019.7.5)] 2019 26th International Workshop on Active-Matrix Flatpanel Displays and Devices (AM-FPD) - How to use Synchrotron Soft X-Ray for Analysis of Perovskite Solar Cell
摘要： Wireless sensor networks (WSNs) can utilize the unlicensed industrial, scientific, and medical (ISM) band to communicate the sensed data. The ISM band has been already saturated due to the overlaid deployment of WSNs. To solve this problem, WSNs have been powered up by cognitive radio (CR) capability. By using CR capability, WSNs can utilize the spectrum holes opportunistically. The sensor nodes, which need large bandwidth to transmit their sensed data from source to destination require some scheme, which should be able to provide them a wide band channel whenever required. Channel bonding (CB) is a technique through which multiple contiguous channels can be combined to form a single wide band channel. By using CB technique, CR-based WSN nodes attempt to find and combine contiguous channels to avail larger bandwidth. In this paper, we show that by increasing the number of channels, the probability of finding contiguous channels decreases. Moreover, we then propose a primary-radio (PR) user-activity-aware CB algorithm and compare it with three state-of-the-art schemes: SWA, KNOWS, and AGILE. It has been demonstrated through extensive NS-2 simulations that intelligent CB decisions can reduce harmful interference to PR nodes. We find that CB in CR sensor networks attempts to provide greater bandwidth and utilizes the spectrum effectively.
关键词： cognitive radio,dynamic spectrum access,Channel bonding,wireless sensor networks
更新于2025-09-23 15:19:57
-
Crosslinkinga??Induced White Light Emission of Poly(Hydroxyurethane) Microspheres for White LEDs
摘要： Nonconjugated luminescent polymers with white light emission are promising for a wide range of applications in display and lighting devices, but their preparation remains a big challenge. Herein, a white-light-emitting nonconjugated poly(hydroxyurethane) microsphere (PHUM) synthesized from the crosslinking reaction of trimethylolpropane tri(cyclic carbonate) ether and 1,6-hexanediamine in chloroform is reported. The resultant PHUMs possess uniform sizes ranging from 12.6 to 21.5 μm. It is proposed that a high crosslinking degree and various hydrogen-bonding strengths induce the formation of carbamate clusters with different sizes and broad distributions, which result in a broad emission spectrum. The cluster-size distribution effect leads to multiple n–π* transitions from various carbamate clusters via through-space conjugation of carbamates, realizing white light emission. In addition, the application of PHUMs as single phosphor combined with a 365 nm UV chip is also demonstrated, with which a white-light-emitting diode with a high color rendering index of up to 95 is obtained. This work confirms that crosslinking can induce multiple emissions, which provides a new clusteroluminescence and polymerization-induced emission system for tunable luminescence emission.
关键词： through-space conjugation,light-emitting diodes,poly(hydroxyurethane) microspheres,clusteroluminescence,H-bonding
更新于2025-09-23 15:19:57
-
Laser tissue bondinga??a new venture into primary periodontal wound closure techniques
摘要： Purpose To evaluate the efficacy of Laser tissue bonding (LTB) by comparing with the routinely used sutures for closure of intraoral surgical wounds after periodontal surgery. Methods Patients enrolled in the study were divided into 2 groups. Seventeen patients were included for a split mouth study where modified periodontal flap operation was performed, and in test side, LTB was carried out whereas in control, conventional suturing. Laser welding of the gingiva was performed with an 810 diode laser with a power of 1.5 W in contact mode. Results A highly statistically significant difference was observed in LTB (test) subgroup when compared with conventional suturing, depicting superiority in terms of Power Doppler analysis of vascularisation, wound healing scores, time consumption and microbial colonization. Conclusion Within the limitations of the study, it was concluded that LTB was effective in achieving wound closure with no morbid complications associated. More long-term randomized controlled trials are required to further prove the efficacy of this novel technique.
关键词： Suturing,Laser tissue bonding,Wound healing,Periodontal flap
更新于2025-09-23 15:19:57
-
Dual Function of Surface Alkali-Gas Erosion on SnO <sub/>2</sub> for Efficient and Stable Perovskite Solar Cells
摘要： The electrical character and interface contact of electron transport layer (ETL) play a critical role on high efficiency planar perovskite solar cells (PSCs). Here, a dual functional surface alkali-gas erosion (SAE) method is proposed based on the unique chemical properties of the amphoteric oxide. Firstly, during the SAE process, the SnO2 can react with alkaline gas slightly and the chemical reaction mechanism is elucidated, which leads to the crystal fusion of the SnO2 surface, bringing an improved electron mobility and an excellent interface contact between SnO2 ETL and perovskite layer. Secondly, SAE method introduced -NH2 group on SnO2 surface chemically can provide nuclear site of perovskite crystal and promote the growth of perovskite film, meanwhile, the -NH2 group connected chemically with SnO2 also serves as a bridge-link by replacing the organic cation at the perovskite/SnO2 interface, which effectively enhances the interfacial charge transport and the perovskite crystallinity. As a consequence, devices with SAE achieve a champion PCE of 21.10% and the average PCE is increased from 18.07% to 20.30%, which mainly results from the increase of short-circuit current density from 22.34 mA/cm2 to 24.19 mA/cm2. Moreover, the optimized devices retain 86% of its initial PCE (compared with 41% of control device) after 60 days at room temperature with 40%–50% humidity.
关键词： Interfacial bonding,Perovskite solar cells,Crystal nucleation,Surface alkali-gas erosion,Surface morphology modulation
更新于2025-09-23 15:19:57
-
Concrete Crack Monitoring Using a Novel Strain Transfer Model for Distributed Fiber Optics Sensors
摘要： In this paper, we study the strain transfer mechanism between a host material and an optical fiber. A new analytical model handling imperfect bonding between layers is proposed. A general expression of the crack-induced strain transfer from fractured concrete material to optical fiber is established in the case of a multilayer system. This new strain transfer model is examined through performing wedge splitting tests on concrete specimens instrumented with embedded and surface-mounted fiber optic cables. The experimental results showed the validity of the crack-induced strain expression fitted to the distributed strains measured using an Optical Backscattering Reflectometry (OBR) system. As a result, precise estimations of the crack openings next to the optical cable location were achieved, as well as the monitoring of the optical cable response through following the strain lag parameter.
关键词： crack,distributed strains,crack opening,wedge splitting test,fiber optics sensors,strain transfer,imperfect bonding,concrete
更新于2025-09-23 15:19:57
-
[IEEE 2019 IEEE SENSORS - Montreal, QC, Canada (2019.10.27-2019.10.30)] 2019 IEEE SENSORS - Brillouin distributed fiber sensor based on a Dual-frequency laser
摘要： Electric ?elds can be effectively used to sense, manipulate, and move particles in lab-on-a-chip devices. Nevertheless, the throughput of such devices is a critical issue, which can be effectively improved by increasing the height of the microchannels. For this purpose, vertical electrodes are needed in order to apply electrical stimuli homogeneously over the full height of the channel. In this paper, we propose different fabrication processes based on a conformal coating of 3-D SU-8 structures with metal layers, de?ning vertical electrodes in micro?uidic channels with high aspect ratio and uniform coating of the vertical sidewalls. We describe two different strategies to achieve the patterning of connection lines inside the gaps of the pillar electrodes—one based on liftoff and the other based on dry ?lm resist. We show how the liftoff approach allows for high connection densities and high resolution of the patterning inside the 3-D electrode arrays. Moreover, we highlight how the dry ?lm process provides an ef?cient and low-cost alternative when neither high-density patterning nor high resolution is needed. Standard resistive and impedance measurements show high conductivity of the structures whose fabrication process grants standard photolithographic resolution in the de?nition of the electrode features.
关键词： vertical electrodes,microelectrode arrays,SU-8,3D microelectrodes,SU-8/PDMS bonding
更新于2025-09-23 15:19:57
-
The role of interfacial H-bonding in electrical properties of UV-cured resin filled with hydroxylated Al2O3 nanoparticles
摘要： Surface hydroxylation of crude Al2O3 (c-Al2O3) nanoparticles by H2O2 was conducted to tailor the electrical properties of UV-cured resin. The hydroxyl groups on Al2O3 particles were designed to establish hydrogen bonding between hydroxyl and carboxyl with that of UV/c-Al2O3 composites at the same filler content. It was found that the addition of 0.5 wt % h-Al2O3 increases the AC breakdown strength and volume resistivity by 15.5 % and 367.9 %, respectively. Our results suggest that the hydroxylation is an efficient way to improve the electrical properties of UV-cured resin nanocomposites, thus promoting stereolithography 3D printing in application of electrical and electronic field.
关键词： Stereolithography,Interfacial region,Hydrogen bonding,Nanocomposites,Interfacial strength,Trap levels,Electrical properties
更新于2025-09-23 15:19:57
-
Adhesion Behavior between Multilayer Graphene and Semiconductor Substrates
摘要： A high bonding strength between graphene and a semiconductor surface is significant to the performance of graphene-based Micro-Electro Mechanical Systems/Nano-Electro Mechanical Systems (MEMS/NEMS) devices. In this paper, by applying a series of constant vertical upward velocities (Vup) to the topmost layer of graphene, the exfoliation processes of multilayer graphene (one to ten layers) from an Si semiconductor substrate were simulated using the molecular dynamics method, and the bonding strength was calculated. The critical exfoliation velocities, adhesion forces, and adhesion energies to exfoliate graphene were obtained. In a system where the number of graphene layers is two or three, there are two critical exfoliation velocities. Graphene cannot be exfoliated when the Vup is lower than the first critical velocity, although the total number of graphene layers can be exfoliated when the Vup is in the range between the first critical velocity and second critical velocity. Only the topmost layer can be exfoliated to be free from the Si surface if the applied Vup is greater than the second critical velocity. In systems where the number of graphene layers is four to ten, only the topmost layer can be free and exfoliated if the exfoliation velocity is greater than the critical velocity. It was found that a relatively low applied Vup resulted in entire graphene layers peeling off from the substrate. The adhesion forces of one-layer to ten-layer graphene systems were in the range of 25.04 nN–74.75 nN, and the adhesion energy levels were in the range of 73.5 mJ/m2–188.45 mJ/m2. These values are consistent with previous experimental results, indicating a reliable bond strength between graphene and Si semiconductor surfaces.
关键词： adhesion force,bonding mechanism,adhesion energy,exfoliation behavior,MEMS/NEMS,molecular dynamics,graphene
更新于2025-09-23 15:19:57
-
Understanding the effects of chlorine ion on water structure from a Raman spectroscopic investigation up to 573?K
摘要： The OH stretch band features on Raman spectra of aqueous KCl?H2O solutions have been investigated at temperatures (T) up to 573 K. KCl greatly reduces the relative intensity of the shoulder at ~3245 cm–1 and the band width, but these effects are slightly reversed at temperatures over ~513 K. Also, KCl causes a blue shift (T < 433 K) but a red shift (T > 433 K) of the main peak. These spectral features are interpreted that Cl? breaks the tetrahedral hydrogen bonding (HB) structure and bonds to water molecules with the non-tetrahedral HB configurations. The single donor is likely the preferred configuration between the water molecules in the Cl? hydration shells. Cl? tends to promote the HB degree in solutions at T > 433 K.
关键词： Temperature,Chlorine ion,Hydrogen bonding,Raman spectroscopy,Water structure
更新于2025-09-19 17:15:36