Local indium segregation and band structure in high efficiencygreen light emitting InGaN/GaN diodes (open access)

Local indium segregation and band structure in high efficiencygreen light emitting InGaN/GaN diodes

GaN/InGaN light emitting diodes (LEDs) are commercialized for lighting applications because of the cost efficient way that they produce light of high brightness. Nevertheless, there is significant room for improving their external emission efficiency from typical values below 10 percent to more than 50 percent, which are obtainable by use of other materials systems that, however, do not cover the visible spectrum. In particular, green-light emitting diodes fall short in this respect, which is troublesome since the human eye is most sensitive in this spectral range. In this letter advanced electron microscopy is used to characterize indium segregation in InGaN quantum wells of high-brightness, green LEDs (with external quantum efficiency as high as 15 percent at 75 A/cm2). Our investigations reveal the presence of 1-3 nm wide indium rich clusters in these devices with indium concentrations as large as 0.30-0.40 that narrow the band gap locally to energies as small as 2.65 eV.
Date: November 23, 2004
Creator: Jinschek, Joerg R.; Erni, Rolf; Gardner, Nathan F.; Kim, AndrewY. & Kisielowski, Christian
Object Type: Article
System: The UNT Digital Library
Calibration Monitor for Dark Energy Experiments (open access)

Calibration Monitor for Dark Energy Experiments

The goal of this program was to design, build, test, and characterize a flight qualified calibration source and monitor for a Dark Energy related experiment: ACCESS - 'Absolute Color Calibration Experiment for Standard Stars'. This calibration source, the On-board Calibration Monitor (OCM), is a key component of our ACCESS spectrophotometric calibration program. The OCM will be flown as part of the ACCESS sub-orbital rocket payload in addition to monitoring instrument sensitivity on the ground. The objective of the OCM is to minimize systematic errors associated with any potential changes in the ACCESS instrument sensitivity. Importantly, the OCM will be used to monitor instrument sensitivity immediately after astronomical observations while the instrument payload is parachuting to the ground. Through monitoring, we can detect, track, characterize, and thus correct for any changes in instrument senstivity over the proposed 5-year duration of the assembled and calibrated instrument.
Date: November 23, 2009
Creator: Kaiser, M. E.
Object Type: Report
System: The UNT Digital Library
Congressional Action on FY2016 Appropriations Measures (open access)

Congressional Action on FY2016 Appropriations Measures

This report provides information on the congressional consideration of the FY2016 regular appropriations bills and the FY2016 continuing resolution (CR). It also discusses the statutory and procedural budget enforcement framework for FY2016 appropriations.
Date: November 23, 2015
Creator: Tollestrup, Jessica
Object Type: Report
System: The UNT Digital Library
Federal Register, Volume 75, Number 225, November 23, 2010, Pages 71325-71518 (open access)

Federal Register, Volume 75, Number 225, November 23, 2010, Pages 71325-71518

Daily publication of the U.S. Office of the Federal Register contains rules and regulations, proposed legislation and rule changes, and other notices, including "Presidential proclamations and Executive Orders, Federal agency documents having general applicability and legal effect, documents required to be published by act of Congress, and other Federal agency documents of public interest" (p. ii). Table of Contents starts on page iii.
Date: November 23, 2010
Creator: United States. Office of the Federal Register.
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Texas Register, Volume 32, Number 47, Pages 8377-8618, November 23, 2007 (open access)

Texas Register, Volume 32, Number 47, Pages 8377-8618, November 23, 2007

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: November 23, 2007
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History