Engineering topics
Fischer, Arthur J.
Publications and source records attributed to Fischer, Arthur J..
Deterministic Fabrication of Quantum Dots for Quantum Light Sources using Selective Photoelectrochemical Etching.
Abstract not provided.
III-nitride photonic crystal emitters by selective photoelectrochemical etching of heterogeneous quantum well structures
We demonstrate a top-down fabrication strategy for creating a III-nitride hole array photonic crystal (PhC) with embedded quantum wells (QWs). Our photoelectrochemical (PEC) etching technique is highly bandgap selective, permitting the removal of QWs with well-defined indium (In) concentration. Room-temperature micro-photoluminescence (μ-PL) measurements confirm the removal of one multiple quantum well (MQW) while preserving a QW of differing In concentration. Moreover, PhC cavity resonances, wholly unobservable before, are present following PEC etching. Our results indicate an interesting route for creating III-nitride membranes with tailorable emission wavelengths. Our top-down fabrication approach offers exciting opportunities for III-nitride based light emitters.
Size-Controlled Photoelectrochemical Etching of InGaN Quantum Dots and GaN Nanowires.
Abstract not provided.
Nanophotonics at Sandia: Tailoring Propagation Emission and Topological behavior of Light.
Abstract not provided.
Visible Quantum Nanophotonics.
The goal of this LDRD is to develop a quantum nanophotonics capability that will allow practical control over electron (hole) and photon confinement in more than one dimension. We plan to use quantum dots (QDs) to control electrons, and photonic crystals to control photons. InGaN QDs will be fabricated using quantum size control processes, and methods will be developed to add epitaxial layers for hole injection and surface passivation. We will also explore photonic crystal nanofabrication techniques using both additive and subtractive fabrication processes, which can tailor photonic crystal properties. These two efforts will be combined by incorporating the QDs into photonic crystal surface emitting lasers (PCSELs). Modeling will be performed using finite-different time-domain and gain analysis to optimize QD-PCSEL designs that balance laser performance with the ability to nano-fabricate structures. Finally, we will develop design rules for QD-PCSEL architectures, to understand their performance possibilities and limits.
Anisotropic heavy-hole g-factors & relevance to photon-to-spin conversion schemes relevance to photon-to-spin conversion schemes.
Abstract not provided.
Deterministic Placement of Quantum-Size Controlled Quantum Dots for Seamless Top-Down Integration
We demonstrate a new route toward the integration and deterministic placement of quantum dots (QDs) within prepatterned nanostructures. Using standard electron-beam lithography (EBL) and inductively coupled plasma reactive-ion etching (ICP-RIE), we fabricate arrays of nanowires on a III-nitride platform. Next, we integrate QDs of controlled size within the prepatterned nanowires using a bandgap-selective, wet-etching technique: quantum-size-controlled photoelectrochemical (QSC-PEC) etching. Low-temperature microphotoluminescence (μ-PL) measurements of individual nanowires reveal sharp spectral signatures, indicative of QD formation. Further, internal quantum efficiency (IQE) measurements reveal a near order of magnitude improvement in emitter efficiency following QSC-PEC etching. Finally, second-order cross-correlation (g(2)(0)) measurements of individual QDs directly confirm nonclassical, antibunching behavior. Lastly, our results illustrate an exciting approach toward the top-down integration of nonclassical light sources within nanophotonic platforms.
InGaN Quantum Dots by Quantum Size Controlled Photoelectrochemical Etching.
Abstract not provided.
Vertical III-nitride thin-film power diode
A vertical III-nitride thin-film power diode can hold off high voltages (kV's) when operated under reverse bias. The III-nitride device layers can be grown on a wider bandgap template layer and growth substrate, which can be removed by laser lift-off of the epitaxial device layers grown thereon.
InGaN Quantum Dots by Quantum Size Controlled Photoelectrochemcial Etching.
Abstract not provided.
Nanophotonic Structures for Topological Photonics and Quantum Light Sources (invited).
Abstract not provided.
Review—Ultra-Wide-Bandgap AlGaN Power Electronic Devices
“Ultra” wide-bandgap semiconductors are an emerging class of materials with bandgaps greater than that of gallium nitride (EG > 3.4 eV) that may ultimately benefit a wide range of applications, including switching power conversion, pulsed power, RF electronics, UV optoelectronics, and quantum information. This paper describes the progress made to date at Sandia National Laboratories to develop one of these materials, aluminum gallium nitride, targeted toward high-power devices. The advantageous material properties of AlGaN are reviewed, questions concerning epitaxial growth and defect physics are covered, and the processing and performance of vertical- and lateral-geometry devices are described. The paper concludes with an assessment of the outlook for AlGaN, including outstanding research opportunities and a brief discussion of other potential applications.
InGaN Quantum Dots by Quantum Size Controlled Photoelectrochemical Etching.
Abstract not provided.
Ultra-Wide Bandgap AlGaN Materials for Electronics and Opto-Electronics (invited).
Abstract not provided.