https://purehost.bath.ac.uk/ws/files/9234686/JMS_2011.pdf

A review of reverse osmosis membrane materials for desalination—Development to date and future potential

Complex (dusty) plasmas: current status, open issues, perspectives

Light-emitting diodes with emission wavelengths less than 400 nm have been developed using the AlInGaN material system. For devices operating at shorter wavelengths, alloy compositions with a greater aluminium content are required. The material properties of these materials lie on the border between conventional semiconductors and insulators, which adds a degree of complexity to the development of efficient light-emitting devices. A number of technical developments have enabled the fabrication of LEDs based on group three nitrides (III-nitrides) that emit in the UV part of the spectrum, providing useful tools for a wealth of applications in optoelectronic systems.

Ultraviolet light-emitting diodes based on group three nitrides

In this paper, we review the recent progress in the resistive random access memory (ReRAM) technology, one of the most promising emerging nonvolatile memories, in which both electronic and electrochemical effects play important roles in the nonvolatile functionalities. First, we provide a brief historical overview of the research in this field. We also provide a technological overview and the epoch-making achievements, followed by an account of the current understanding of both bipolar and unipolar ReRAM operations. Finally, we summarize the challenges facing the ReRAM technology as it moves toward the beyond-2X-nm generation of nonvolatile memories and the so-called beyond complementary metal-oxide-semiconductor (CMOS) device.

Resistive Random Access Memory (ReRAM) Based on Metal Oxides

Resistive Random Access Memory (ReRAM) Based on Metal Oxides This paper reviews a class of metal-oxide-metal resistive memory structures that depend on a chemical oxidation/reduction process to cause a change in resistance when a voltage pulse is applied.

Continuous-wave (CW) operation of nonpolar m-plane InGaN/GaN laser diodes (LDs) with the lasing wavelengths approximately 400 nm was demonstrated. The threshold current was 36 mA (4.0 kA/cm2) for the CW operation [28 mA (3.1 kA/cm2) for pulsed mode], being comparable to that of conventional c-plane violet LDs. Both the LDs with the stripes parallel to a- and c-axes showed TE mode operation, according to the polarization selection rules of the transitions in strained InGaN. The c-axis stripe LDs exhibited lower threshold current density, since the lowest energy transition is allowed. As is the case with the m-plane light emitting diodes fabricated on the free-standing m-plane GaN bulk crystals [Okamoto et al.: Jpn. J. Appl. Phys. 45 (2006) L1197], the LDs shown in this paper did not have distinct dislocations, stacking faults, or macroscopic cracks. Nonpolar m-plane GaN-based materials are coming into general use.

http://iopscience.iop.org/article/10.1143/JJAP.46.L187/pdf

Continuous-Wave Operation of m-Plane InGaN Multiple Quantum Well Laser Diodes

Completely vertical trench gate metal oxide semiconductor field-effect transistors (MOSFETs) have been produced using gallium nitride (GaN) for the first time. These MOSFETs exhibited enhancement-mode operation with a threshold voltage of 3.7 V and an on-resistance of 9.3 mΩcm2. The channel mobility was estimated to be 131 cm2/(Vs) when all the resistances except for that of the channel are considered. Such structures, which satisfy the key words "vertical", "trench gate", and "MOSFET", will enable us to fabricate practical GaN-based power switching devices.

https://iopscience.iop.org/article/10.1143/APEX.1.011105/pdf

Vertical GaN-Based Trench Gate Metal Oxide Semiconductor Field-Effect Transistors on GaN Bulk Substrates

An inventive semiconductor laser diode includes a Group III nitride semiconductor layered structure having a major crystal growth plane defined by a non-polar or semi-polar-plane. The Group III nitride semiconductor layered structure includes: a p-type cladding layer and an n-type cladding layer; an In-containing p-type guide layer and an In-containing n-type guide layer held between the p-type cladding layer and the n-type cladding layer; and an In-containing light emitting layer held between the p-type guide layer and the n-type guide layer.

Semiconductor laser diode

Blue laser diodes (LDs) based on m-plane gallium nitride were demonstrated by using m-plane GaN substrates The lasing wavelength and the threshold current under pulsed operation were 4518 nm and 134 mA (223 kA/cm2), respectively The device structures consisted of InGaN-based multi-quantum wells, InGaN guiding layers, and Al-containing cladding layers The InGaN guiding layers play two roles; as appropriate optical waveguides for longer lasing wavelengths and for the prevention of macroscopic cracks parallel to the c-plane The latter is an indispensable technology in order to fabricate nonpolar LDs for longer wavelengths beyond the blue region

https://iopscience.iop.org/article/10.1143/JJAP.46.L820/pdf

Pure Blue Laser Diodes Based on Nonpolar m-Plane Gallium Nitride with InGaN Waveguiding Layers

The wave dispersion relations in the fluid phase of Yukawa systems are obtained from molecular dynamics (MD) simulations for a wide range of the parameters. The Yukawa system is a collection of particles interacting through Yukawa (i.e., screened Coulomb) potentials, which can serve as a simple model for dusty plasmas. Our simulations have clearly shown that the transverse wave dispersion has a cutoff at a long wavelength even in the case of weak screening. The MD simulation data are compared with earlier theoretical predictions of the Yukawa dispersion relations and the validity of these theories is clarified.

/pdf/wave-dispersion-relations-in-yukawa-fluids-hlz9d4i7ge.pdf

Hiroaki Ohta

Papers

Continuous-Wave Operation of m-Plane InGaN Multiple Quantum Well Laser Diodes

Vertical GaN-Based Trench Gate Metal Oxide Semiconductor Field-Effect Transistors on GaN Bulk Substrates

Semiconductor laser diode

Pure Blue Laser Diodes Based on Nonpolar m-Plane Gallium Nitride with InGaN Waveguiding Layers

Wave dispersion relations in Yukawa fluids.