Physics and possibility for new device applications in GaN-based p-i-n structures

2003 ◽  
Author(s):  
Eunsoon Oh
2021 ◽  
pp. 1-8
Author(s):  
Neha Siddiqui ◽  
Ryan G. Chiu ◽  
Ravi S. Nunna ◽  
Georgia Glastris ◽  
Ankit I. Mehta

OBJECTIVE The US FDA uses evidence from clinical trials in its determination of safety and utility. However, these trials have often suffered from limited external validity and generalizability due to unrepresentative study populations with respect to clinical patient demographics. Section 907 of the FDA Safety and Innovation Act (FDASIA) of 2012 attempted to address this issue by mandating the reporting of certain study demographics in new device applications. However, no study has been performed on its effectiveness in the participant diversity of neurosurgical device trials. METHODS The FDA premarket approval (PMA) online database was queried for all original neurosurgical device submissions from January 1, 2006, to December 31, 2019. Endpoints of the study included racial and gender demographics of reported effectiveness trials, which were summated for each submission. Chi-square tests were performed on both endpoints for before and after years of FDASIA passage and implementation. RESULTS A total of 33 device approvals were analyzed, with 14 occurring before SIA implementation and 19 after. Most trials (96.97%) reported gender to the FDA, while 66.67% reported race and 63.64% reported ethnicity. Gender breakdown did not change significantly post-SIA (53.30% female, p = 0.884). Racial breakdown was significantly different from the 2010 US Census for all races (p < 0.001) both pre- and post-SIA. Only Native American race was significantly different in terms of representation post-SIA, increasing from 0% to 0.63% (p = 0.0187). There was no significant change in ethnicity. CONCLUSIONS The FDASIA, as currently written, does not appear to have had a significant impact on the racial or gender diversity of neurosurgical device clinical trial populations. This may be due to the noncompulsory nature of its guidance, or a lack of more stringent regulation on the composition of clinical trials themselves.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Bo Chen ◽  
Fucong Fei ◽  
Dongqin Zhang ◽  
Bo Zhang ◽  
Wanling Liu ◽  
...  

Abstract Magnetic topological insulators (MTIs) offer a combination of topologically nontrivial characteristics and magnetic order and show promise in terms of potentially interesting physical phenomena such as the quantum anomalous Hall (QAH) effect and topological axion insulating states. However, the understanding of their properties and potential applications have been limited due to a lack of suitable candidates for MTIs. Here, we grow two-dimensional single crystals of Mn(SbxBi(1-x))2Te4 bulk and exfoliate them into thin flakes in order to search for intrinsic MTIs. We perform angle-resolved photoemission spectroscopy, low-temperature transport measurements, and first-principles calculations to investigate the band structure, transport properties, and magnetism of this family of materials, as well as the evolution of their topological properties. We find that there exists an optimized MTI zone in the Mn(SbxBi(1-x))2Te4 phase diagram, which could possibly host a high-temperature QAH phase, offering a promising avenue for new device applications.


1977 ◽  
Vol 3 (4) ◽  
pp. 225-231
Author(s):  
H. L. Hartnagel

Recently a greater understanding of the physics and chemistry of anodic oxide growth on III-V compound semiconductors has become available. These details are reviewed and critically assessed. With the data avilable now new device applications can be considered.


2000 ◽  
Vol 633 ◽  
Author(s):  
Alper Buldum ◽  
Jian Ping Lu

AbstractQuantum transport properties of intermolecular nanotube contacts are investigated. We find that atomic structure in the contact region plays important roles and resistance of contacts varies strongly with geometry and nanotube chirality. Nanotube end-end contacts have low resistance and show negative differential resistance (NDR) behavior. Exerting small pressure/force between the tubes can dramatically decrease contact resistance, if the contact is commensurate. Significant variation and nonlinearity of contact resistance may lead to new device applications.


1994 ◽  
Vol 356 ◽  
Author(s):  
C. H. Lin ◽  
H. C. Kuo ◽  
Y. Lu ◽  
H. Shen ◽  
J. Pamulapati ◽  
...  

AbstractResearch of the strain effect on semiconductors and their heterostructures has generated increasing interests due to its important device applications. We have developed a eutectic bonding technique to create in-plane anisotropic strain in GaAs/AlGaAs multiple quantum well (MQW) thin films. MQW thin films grown on (100) GaAs substrates were bonded to (100) GaAs, (100) Si and Y-cut LiNbO3 submounts with a Au/Sn eutectic alloy. The bonding materials consist of Au/Sn multilayer (80 wt% Au and 20 wt% Sn; 0.95μm) with a Cr (500Å) adhesion layer. The bonding process was optimized by carefully choosing the annealing conditions. After bonding, the substrates of the MQWs were removed by wet chemical etching. The in-plane strain was induced in MQW thin film due to the different thermal expansion between the thin film and submount. The strain was characterized using X-ray rocking curve. The microstructures of bonding interfaces and MQW thin films were examined by scanning electron microscope(SEM) and cross-section transmission electron microscope (XTEM). This bonding technique can be used for many new device applications which take the advantage of in-plane strain, as well as for device integration.


1997 ◽  
Vol 483 ◽  
Author(s):  
H. Paul Maruska ◽  
Mike Lioubtchenko ◽  
Thomas G. Tetreault ◽  
Marek Osinskif ◽  
Stephen J. Pearton ◽  
...  

AbstractWith great attention now being given to the wide band gap materials for electronic and optoelectronic device applications, there is interest in using ion implantation to introduce dopants into selected regions of devices. Work on ion implantation into SiC and the III-V nitrides is reviewed, new device concepts are given, and recent results are presented. These include SiC implantations at elevated temperatures, a GaN sample implanted with Si having an electron mobility after annealing of 106 cm2/V-s, and a novel GaN np junction diode created by implantation.


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