Enhanced Photoluminescence from Erbium-Doped Gap Microdisk Resonator

1995 ◽  
Vol 392 ◽  
Author(s):  
D. Y. Chu ◽  
X. Z. Wang ◽  
W. G. Bi ◽  
R. P. Espindola ◽  
S. L. Wu ◽  
...  
Keyword(s):  
Thin Film ◽  
Gallium Phosphide ◽  
Sapphire Laser ◽  
Pumping Power ◽  
Film Sample ◽  
Power Intensity ◽  
Enhanced Photoluminescence ◽  
Erbium Doped ◽  
Order Of Magnitude ◽  
Microdisk Resonator

AbstractThe fabrication and optical properties of an erbium-doped gallium phosphide microdisk resonator pumped by a Ti-sapphire laser at 980 nm were investigated. Enhanced Er3+ intra-4f-shell photoluminescence was observed in the microdisk resonator compared to a thin film, and is attributed to a microcavity effect. At low pumping power intensity, the photoluminescence from erbium-doped gallium phosphide microdisks is an order of magnitude more intense than that from a thin film sample.

Observation of enhanced photoluminescence in erbium‐doped semiconductor microdisk resonator

1995 ◽  
Vol 66 (21) ◽  
pp. 2843-2845 ◽  
Author(s):  
D. Y. Chu ◽  
S. T. Ho ◽  
X. Z. Wang ◽  
B. W. Wessels ◽  
W. G. Bi ◽  
...  
Keyword(s):  
Enhanced Photoluminescence ◽  
Erbium Doped ◽  
Microdisk Resonator

Hot-Wire Deposited Amorphous Silicon Thin-Film Transistors

1996 ◽  
Vol 424 ◽  
Author(s):  
R. E. I. Schropp ◽  
K. F. Feenstra ◽  
C. H. M. Van Der Werf ◽  
J. Holleman ◽  
H. Meiling
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Current Crowding ◽  
Hot Wire ◽  
Saturation Regime ◽  
Silicon Thin Film ◽  
Order Of Magnitude

AbstractWe present the first thin film transistors (TFTs) incorporating a low hydrogen content (5 - 9 at.-%) amorphous silicon (a-Si:H) layer deposited by the Hot-Wire Chemical Vapor Deposition (HWCVD) technique. This demonstrates the possibility of utilizing this material in devices. The deposition rate by Hot-Wire CVD is an order of magnitude higher than by Plasma Enhanced CVD. The switching ratio for TFTs based on HWCVD a-Si:H is better than 5 orders of magnitude. The field-effect mobility as determined from the saturation regime of the transfer characteristics is still quite poor. The interface with the gate dielectric needs further optimization. Current crowding effects, however, could be completely eliminated by a H2 plasma treatment of the HW-deposited intrinsic layer. In contrast to the PECVD reference device, the HWCVD device appears to be almost unsensitive to bias voltage stressing. This shows that HW-deposited material might be an approach to much more stable devices.

scholarly journals Tripod-Loop Metasurfaces for Terahertz-Sensing Applications: A Comparison

2020 ◽  
Vol 10 (18) ◽  
pp. 6504
Author(s):  
Irati Jáuregui-López ◽  
Bakhtiyar Orazbayev ◽  
Victor Pacheco-Peña ◽  
Miguel Beruete
Keyword(s):  
Thin Film ◽  
Electric Field ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Ring Resonators ◽  
Film Sensor ◽  
Average Value ◽  
Sensing Applications ◽  
Order Of Magnitude ◽  
Hole Arrays

The high electric field intensity achieved on the surface of sensors based on metasurfaces (metasensors) makes them an excellent alternative for sensing applications where the volume of the sample to be identified is tiny (for instance, thin-film sensing devices). Various shapes and geometries have been proposed recently for the design of these metasensors unit-cells (meta-atoms) such as split ring resonators or hole arrays, among others. In this paper, we propose, design, and evaluate two types of tripod metasurfaces with different complexity in their geometry. An in-depth comparison of their performance is presented when using them as thin-film sensor devices. The meta-atoms of the proposed metasensors consist of a simple tripod and a hollow tripod structure. From numerical calculations, it is shown that the best geometry to perform thin-film sensing is the compact hollow tripod (due to the highest electric field on its surface) with a mean sensitivity of 3.72 × 10−5 nm−1. Different modifications are made to this structure to improve this value, such as introducing arms in the design and rotating the metallic pattern 30 degrees. The best sensitivity achieved for extremely thin film analytes (5–25 nm thick) has an average value of 1.42 × 10−4 nm, which translates into an extremely high improvement of 381% with respect to the initial hollow tripod structure. Finally, a comparison with other designs found in the literature shows that our design is at the top of the ranking, improving the overall performance by more than one order of magnitude. These results highlight the importance of using metastructures with more complex geometries so that a higher electric field intensity distribution and, therefore, designs with better performance can be obtained.

scholarly journals Generation of Ultrafast Erbium-Doped Fiber Laser (EDFL) utilizing Graphene Thin Film

2020 ◽  
Vol 1484 ◽  
pp. 012026
Author(s):  
Muhammad Aizi Mat Salim ◽  
Mohd Afiq Ismail ◽  
Mohd. Zulhakimi Ab. Razak ◽  
Saaidal Razalli Azzuhri
Keyword(s):  
Thin Film ◽  
Fiber Laser ◽  
Erbium Doped

Hot-Wire Deposited Amorphous Silicon Thin-Film Transistors

1996 ◽  
Vol 420 ◽  
Author(s):  
R. E. I. Schropp ◽  
K. F. Feenstra ◽  
C. H. M. Van Der Werf ◽  
J. Holleman ◽  
H. Meiling
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Current Crowding ◽  
Hot Wire ◽  
Saturation Regime ◽  
Silicon Thin Film ◽  
Order Of Magnitude

AbstractWe present the first thin film transistors (TFTs) incorporating a low hydrogen content (5 - 9 at.-%) amorphous silicon (a-Si:H) layer deposited by the Hot-Wire Chemical Vapor Deposition (HWCVD) technique. This demonstrates the possibility of utilizing this material in devices. The deposition rate by Hot-Wire CVD is an order of magnitude higher than by Plasma Enhanced CVD. The switching ratio for TFTs based on HWCVD a-Si:H is better than 5 orders of magnitude. The field-effect mobility as determined from the saturation regime of the transfer characteristics is still quite poor. The interface with the gate dielectric needs further optimization. Current crowding effects, however, could be completely eliminated by a H2 plasma treatment of the HW-deposited intrinsic layer. In contrast to the PECVD reference device, the HWCVD device appears to be almost unsensitive to bias voltage stressing. This shows that HW-deposited material might be an approach to much more stable devices.

A valence-selective X-ray fluorescence holography study of an yttrium oxide thin film

2017 ◽  
Vol 50 (6) ◽  
pp. 1583-1589 ◽  
Author(s):  
J. R. Stellhorn ◽  
S. Hosokawa ◽  
N. Happo ◽  
H. Tajiri ◽  
T. Matsushita ◽  
...  
Keyword(s):  
Thin Film ◽  
Absorption Edge ◽  
Structural Information ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Oxide Thin Film ◽  
Film Sample ◽  
Epitaxial Thin Film ◽  
X Ray ◽  
Valence States

The first direct valence-selective structure determination by X-ray fluorescence holography is reported. The method is applied to investigate an epitaxial thin film of the rare earth monoxide YO, which has recently been synthesized by pulsed laser deposition. The surface of the sample is easily oxidized to Y2O3. In order to separate the structural information connected with the two different valence states of Y, the X-ray fluorescence holography measurements were performed close to the YKabsorption edge. Using the shift of the absorption edge for the different valence states, very different relative contributions of YO and Y2O3are obtained. Thus, it is possible to distinguish the crystal structures of YO and Y2O3in the thin-film sample.

Initial Contact Behavior of Nanograined Ni-25at.%Al Film During Nanoindentation

2004 ◽  
Vol 841 ◽  
Author(s):  
Han. Li ◽  
Alfonso H. W. Ngan
Keyword(s):  
Thin Film ◽  
Repeated Loading ◽  
Initial Contact ◽  
Al Alloy ◽  
Alloy Thin Film ◽  
Thin Film Sample ◽  
Film Sample ◽  
Microscopy Imaging ◽  
Contact Stage ◽  
Average Grain Size

ABSTRACTCyclic indentation was performed on standard fused quartz, single crystal Ni3Al (111) and nanocrystalline Ni-25at. %Al alloy thin film with average grain size of a few nanometers. For the thin film sample, it is found the scattering of the effective Young's modulus at small depths goes far beyond the expectation from effects due to surface roughness alone. Three representative deformation mechanisms during initial contact stage were identified to be responsible for the scattering with the assistance of immediate pre and post indentation atomic force microscopy imaging. Furthermore, repeated loading was found to stiffen the thin film sample, but not the bulk ones.

Solar-Blind 4H-SiC Avalanche Photodiodes

2009 ◽  
Vol 615-617 ◽  
pp. 873-876 ◽  
Author(s):  
Stanislav I. Soloviev ◽  
Alexey V. Vert ◽  
Jody Fronheiser ◽  
Peter M. Sandvik
Keyword(s):  
Thin Film ◽  
Avalanche Photodiodes ◽  
Optical Filter ◽  
Leakage Currents ◽  
Avalanche Photodetectors ◽  
Rejection Ratio ◽  
Solar Blind ◽  
Order Of Magnitude

In this work, solar-blind UV 4H-SiC avalanche photodetectors were fabricated and tested in linear and Geiger modes. APDs with both PIN and separate absorption and multiplication (SAM) structures were investigated. PIN structures demonstrated higher quantum efficiencies while the SAM structure exhibit lower leakage currents. Deposition of a thin film optical filter on top of the devices was used to provide a high photon rejection ratio of (Stas add value here). However, an external filter showed a better photon rejection ratio compared to the deposited one by about one order of magnitude.

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