Effective light emission from low-dimensional silicon materials such as porous silicon, silicon nanocrystals, and superlattices has been demonstrated at room temperature in spite of the indirect bandgap nature of bulk silicon. [1][2][3][4][5] In particular, silicon quantum dot (Si QD) light-emitting diodes (LEDs) have recently been investigated as a promising light source for the next generation of optical interconnections. [6][7][8] However, the quest for highly efficient Si QD LEDs remains unfulfilled. To achieve this goal, new LED structures are being developed to enhance the external quantum efficiency (h ext ), which is a product of the light-extraction efficiency (h extraction ), radiative efficiency (h rad ), and current-injection efficiency (h inj ). [9] Among the new approaches, increasing the radiative recombination rate by coupling QDs to surface plasmons (SPs, collective charge oscillations at the interface between a metal and a dielectric material) has attracted a great deal of attention. [10][11][12] Although enhanced photoluminescence (PL)of SP-coupled nanostructures such as QDs [13][14][15][16][17] and quantum wells (QWs) [18] has been reported, there has been no report concerning the enhancement of electroluminescence (EL) in Si QD LEDs through a Si QD-SP coupling effect. Here, we show the first evidence of enhanced h ext in a Si QD LED resulting from the coupling between Si QDs and localized surface plasmons (LSPs) and effective current tunneling into Si QDs from an Ag layer containing Ag particles inserted between the Si QD layer and Si substrate. Surface plasmon excitations in bounded geometries, such as nanostructured metallic particles, are LSPs. The resonant excitation of LSPs on the surface of nanostructured metallic particles by an incident electromagnetic field (light) causes strong light scattering and absorption, and enhanced local electromagnetic fields. LSPs are generally used in many applications such as ultrafast switches, optical tweezers, labeling biomolecules, optical filters, biosensors, surface-enhanced spectroscopies, plasmonics, and chemical sensors. [19][20][21][22] SPs are evanescent waves that exponentially decay with distance from a metal surface. Si QDs located within the near-field of the metal surface can be effectively coupled to SP mode. [13,18,19] In order to keep the close distance between SiQDs and the metal layer for Si QD-LSP coupling, we propose a Si QD LED structure with an Ag layer containing Ag particles inserted between the silicon nitride layer containing Si QDs and the Si substrate layer, as shown in Figure 1. Figure 2a and b shows cross-sectional transmission electron microscopy (TEM) images of Si QD LEDs with and without an Ag layer. Figure 2a depicts the interface between the silicon nitride and Si substrate of a reference Si QD LED. Figure 2b is an image of the interfaces between the silicon nitride layer, Ag layer, and the Si substrate. The silicon nitride film deposited on the Ag layer was similar in thickness to the silicon nitride layer in the re...

BackgroundControversies persist regarding the effect of prokinetics for the treatment of functional dyspepsia (FD). This study aimed to assess the comparative efficacy of prokinetic agents for the treatment of FD.MethodsRandomized controlled trials (RCTs) of prokinetics for the treatment of FD were identified from core databases. Symptom response rates were extracted and analyzed using odds ratios (ORs). A Bayesian network meta-analysis was performed using the Markov chain Monte Carlo method in WinBUGS and NetMetaXL.ResultsIn total, 25 RCTs, which included 4473 patients with FD who were treated with 6 different prokinetics or placebo, were identified and analyzed. Metoclopramide showed the best surface under the cumulative ranking curve (SUCRA) probability (92.5%), followed by trimebutine (74.5%) and mosapride (63.3%). However, the therapeutic efficacy of metoclopramide was not significantly different from that of trimebutine (OR:1.32, 95% credible interval: 0.27–6.06), mosapride (OR: 1.99, 95% credible interval: 0.87–4.72), or domperidone (OR: 2.04, 95% credible interval: 0.92–4.60). Metoclopramide showed better efficacy than itopride (OR: 2.79, 95% credible interval: 1.29–6.21) and acotiamide (OR: 3.07, 95% credible interval: 1.43–6.75). Domperidone (SUCRA probability 62.9%) showed better efficacy than itopride (OR: 1.37, 95% credible interval: 1.07–1.77) and acotiamide (OR: 1.51, 95% credible interval: 1.04–2.18).ConclusionsMetoclopramide, trimebutine, mosapride, and domperidone showed better efficacy for the treatment of FD than itopride or acotiamide. Considering the adverse events related to metoclopramide or domperidone, the short-term use of these agents or the alternative use of trimebutine or mosapride could be recommended for the symptomatic relief of FD.Electronic supplementary materialThe online version of this article (doi:10.1186/s12876-017-0639-0) contains supplementary material, which is available to authorized users.

Ga-doped ZnO ͑ZnO:Ga͒ films were grown by metalorganic chemical vapor deposition as transparent conducting layers for GaN light-emitting diodes ͑LEDs͒. The forward voltage of LEDs with ZnO:Ga was 3.3 V at 20 mA. The low forward voltage was attributed to the removal of a resistive ZnGa 2 O 4 phase, decreased resistivity of ZnO:Ga films, and increased hole concentration in p-GaN by thermal annealing process. The light output power of LEDs with ZnO:Ga was increased by 25% at 20 mA compared to that of LEDs with Sn-doped indium oxide due to the enhanced transmittance and the increased hole concentration in p-GaN.

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