A survey of Gallium Nitride HEMT for RF and high power applications

Crosstalk is probably one of the main perceptual factors contributing to perceived image quality and visual comfort. The Video Quality Experts Group (VQEG) within their 3D video quality project is specifying a practical measurement procedure that will produce consistent results across laboratories. This paper is part of that effort. Two different method of measuring cross talk on shutter glasses stereo displays have been studied. One is based on time average luminance measurements and the other on temporal measurements. The results show that crosstalk is roughly 0.5% but that there are differences in the crosstalk between the two eyes in the shutter glasses. ©2011 Society for Information Display

SID Symposium Digest of Technical Papers

Are smartphones really that bad? Improving the psychological measurement of technology-related behaviors

The field of spintronics has triggered an enormous revolution in information storage since the first observation of giant magnetoresistance (GMR). Molecular semiconductors are characterized by having very long spin relaxation times up to milliseconds, and are thus widely considered to hold immense potential for spintronic applications. Along with the development of molecular spintronics, it is clear that the study of multipurpose spintronic devices has gradually grown into a new research and development direction. The abundant photoelectric properties of molecular semiconductors and the intriguing functionality of the spinterface, together with novel designs of device structures, have promoted the integration of multiple functions and different mechanisms into discrete spintronic devices. Here, according to the different relationships between the integrated mechanisms, multifunctional molecular spintronic devices containing parallel and interactive types are highlighted. This is followed by the introduction of pure-spin-current-type molecular spintronic devices that have already demonstrated great potential for multifunction exploration. Finally, the challenges and outlook that make this field young and energetic are outlined.

Recent Advances in Molecular Spintronics: Multifunctional Spintronic Devices.

The impact of Er/Yb co-doping on the spectroscopic performance of bismuth borophosphate glasses for photonic applications

A single layer of amorphous InZnO is chosen as the channel material for a thin film transistor (TFT)-based driver and sensing layer for a blue-light sensor, respectively, with a completely compatible process integrated into in-cell embedded photo sensor architecture. The photo sensor exhibits a high optical responsivity (1280 A/W) and excellent signal to noise ratio (~105) under the blue light illumination. Afterwards, the detail studies and important issues about the sensing and material characteristics of a-IZO thin film in the TFT sensor are well discussed. The results suggest that the numbers of the deep, neutral oxygen vacancy are the key factors for carrier generation under illumination. In addition, a positive gate pulse is applied on the devices to eliminate persistent photoconductivity in order to ensure the recover ability for the photo sensor application. The practical concepts of a sensor circuit, which can be integrated on RGB pixel with interactive display, are also proposed on the basis of photo sensor TFT.

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Highly Responsive Blue Light Sensor with Amorphous Indium-Zinc-Oxide Thin-Film Transistor based Architecture.

The flexible conductive-bridging random access memory (CBRAM) device using a Cu/TiW/Ga2O3/Pt stack is fabricated on polyimide substrate with low thermal budget process. The CBRAM devices exhibit good memory-resistance characteristics, such as good memory window (>105), low operation voltage, high endurance (>1.4 × 102 cycles), and large retention memory window (>105). The temperature coefficient of resistance in the filament confirms that the conduction mechanism observed in the Ga2O3 layer is similar with the phenomenon of electrochemical metallization (ECM). Moreover, the performance of CBRAM device will not be impacted during the flexibility test. Considering the excellent performance of the CBRAM device fabricated by low-temperature process, it may provide a promising potential for the applications of flexible integrated electronic circuits.

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Highly durable and flexible gallium-based oxide conductive-bridging random access memory.

This study investigates the electrical characteristics and physical analysis for an amorphous tungsten-doped indium-zinc oxide thin film transistor with different backchannel passivation layers (BPLs), which were deposited by an ion bombardment-free process. A 10 times increase in mobility was observed and attributed to the generation of donor-like oxygen vacancies at the backchannel, which is induced by the oxygen desorption and Gibbs free energy of the BPL material. The mechanism was well studied by XPS analysis. On the other hand, a HfO2 gate insulator was applied for the InWZnO TFT device to control the extremely conductive channel and adjust the negative threshold voltage. With both a HfO2 gate insulator and a suitable BPL, the InWZnO TFT device exhibits good electrical characteristics and a remarkable lifetime when exposed to the ambient air.

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Mobility enhancement for high stability tungsten-doped indium-zinc oxide thin film transistors with a channel passivation layer

We demonstrate the characteristics of a conductive-bridging random access memory (CBRAM) with Cu/TiW/InGaZnO/Ga2O3/Pt stack structure. The addition of a thin metal-oxide layer (4.5 nm-thick Ga2O3) in the bottom of the CBRAM device significantly increases the off-state resistance (ROFF) and the memory window. The IGZO bi-layer CBRAM shows the excellent memory performances, such as low operation current (down to 50 μA), high on/off resistance ratio (>103), high switching endurance (up to 103 cycles) and the capability of multi-level tuning. Meanwhile, high thermal stability was also achieved. Three decades of resistance window is constantly maintained beyond 104 s at 85 °C. The resistive switching stability and electrical uniformity of bi-layer IGZO/Ga2O3 CBRAM device are obviously enhanced as compared with the one only with a single layer of IGZO film. These results have given a great potential for the transparent amorphous oxide semiconductor (TAOS)-based material utilizing in CBRAM stacks and integrating into the display circuits for future memory-in-pixel applications.

TAOS based Cu/TiW/IGZO/Ga2O3/Pt bilayer CBRAM for low-power display technology

The effects of radiation on tungsten doped indium oxide (IWO) thin-film transistors (TFTs) have been well investigated in this Letter. In order to achieve high stability and excellent electrical performance simultaneously even in high ionizing radiation damage ambient, different concentrations of tungsten dopant have been introduced for the TFT device fabrication. It is interesting that the high energy ionizing radiation may significantly increase the conductivity and influence the total concentration of oxygen vacancy in the transparent amorphous oxide semiconductor material, which may be completely different from the traditional radiation damage effect for silicon based CMOS devices. However, that abnormal phenomenon will be effectively suppressed by the powerful carrier suppressor, tungsten, which may have a high oxygen bond dissociation energy. Therefore, IWO devices with a 4% tungsten oxide dopant might be the optimized result even after high dosage ionizing radiation exposure. Hence, it may provide a promising radiation hardness approach to improve both the electrical characteristics and reliability for next generation displays, which can be used in the control system of nuclear power generation or space technology.

Dun-Bao Ruan

Papers

Highly Responsive Blue Light Sensor with Amorphous Indium-Zinc-Oxide Thin-Film Transistor based Architecture.

Highly durable and flexible gallium-based oxide conductive-bridging random access memory.

Mobility enhancement for high stability tungsten-doped indium-zinc oxide thin film transistors with a channel passivation layer

TAOS based Cu/TiW/IGZO/Ga2O3/Pt bilayer CBRAM for low-power display technology

Role of tungsten dopants in indium oxide thin-film transistor on radiation hardness technology