Solid State Physics

Fabrication Process and Application of Magnetic Multilayered Devices [ 下載 PDF ]

Guo-Hau Lai, Hung-Chi Han, Jong-Ching Wu

In the advanced development of modern technology and driven by improving the sensitivity, versatility and reducing the size of electronic products, process of miniaturization has become one of the most important research since the late last century. From the viewpoint of materials science development, the trend has inevitably moved from three-dimensional bulk to two-dimensional thin film regime, and furthermore moved into one-dimensional nano-devices. Among the most attractive materials research the fundamental physics and nanostructured techniques of magnetic material has emerged at the forefront of global research community due to the rapid development of information science and technology in the last two decades or so. Herein, the advancement of magnetic multilayers is introduced, especially the fabrication process and applications of magnetoresistive devices are focused.

How to Analyze the Non-Collinear Synthetic Ferrimagnets with Ferromagnetic Resonance [ 下載 PDF ]

You-Sheng Chen, Jauyn Grace Lin

In this report, we demonstrate the method of ferromagnetic resonance to analyze a non-collinear synthetic ferrimagnet. With this method, we make up the shortage of the traditional methods that only allow one to analyze the static magnetizations for non-collinear magnetic multilayers. By fitting the angular dependent ferromagnetic resonance spectra, one could estimate the accurate values for magnetic anisotropy, the magnetization of individual layer and the exchange coupling constant between layers. As the spintronic devices require more and more complex multilayer components in the visible future, the ferromagnetic resonance technology would play an important role in the industrious applications.

MRAM: a Promising Non-Volatile Memory [ 下載 PDF ]

Po-Chuan Chen, Po-Hung Lin, Chih-Huang Lai

Magnetic random access memory (MRAM) has been regarded as an important memory because of its fast readwrite operation, non-volatility and capability of integration to current semiconductor process. In this article, we will go through different operating mechanisms of MRAM: toggle-mode type, recent spin-transfer torque (STT) type and spin-orbit torque (SOT) type. The operating mechanism changes from applying magnetic field to only a single, fast pulse, and thus accomplishes the fast read-write process. This article will also describe about the challenges of SOT, and corresponding solutions.

Atomic Foundry of Functional Oxides [ 下載 PDF ]

Ying-Hao Chu

The atomic foundry of functional oxides has been built up in National Chiao Tung University since 2009. It has been one of the most active research groups in the research field of oxide heteroepitaxy. More importantly, the integration of resources, the education of young generation, and the communication of researchers from different fields are the signatures of such a platform. In this article, in order to attract more researchers in Taiwan to join this research field, the working principle of such a key facility will be introduced to provide an overview of the capability of this growth platform.

Semiconductor Microcavity Polariton Laser [ 下載 PDF ]

Yu-Hsun Chou, Tien-Chang Lu

In a high quality factor microcavity, photons can strongly couple with the excitons, formed by electrons and holes by Coulomb interaction in solid materials, to generate a new kind of quasi-particle, called exciton-polariton or polariton, with half-matter and half-light characteristics. Polariton is a kind of Boson, which is able to form Bose- Einstein condensation through stimulated scattering of polaritons at the ground state and to emit coherent photons when polaritons escape from the cavity. Recently, semiconductor microcavities have been considered as a promising solid light sources because they can potentially be applied in vertical-cavity surface emitting lasers, single photon sources and other optoelectronic devices^(1-6). In this report, we not only give an introduction to semiconductor microcavity polariton lasers, but also introduce the technology we need to characterize the polariton lasers.

Growth and Characterization of In-rich In_xAl_1−xN Alloys on Si(111) Substrate by RF-MOMBE [ 下載 PDF ]

Wei-Chun Chen

InN-based materials are a potential material for various devices such as infrared light emitters and high effi ciency optoelectronic device because of it is high mobility and narrow band gap of 0.6–0.8 eV. However, the InN is difficult to grow high-crystalline-quality InN owing to its low dissociation temperature and the lack of lattice-matched substrates. In-rich InAlN films were grown directly on Si(111) substrate by RF-MOMBE without any buffer layer. InAlN films were grown at various substrate temperatures in the range of 460–540 °C with TMIn/TMAl ~ 3.3. Structural properties of InAlN ternary alloys were investigated with x-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM). The XRD results indicated that In-rich InAlN films grown with the 460 °C has the smallest full width at half maximum value of 108 arcmin for (0002) X-ray rocking curve (XRC). Also, ross-sectional TEM from InAlN grown on Si(111) at 460 °C shows that the epitaxial film is in direct contact with orientation relationship of InAlN (0002)_InAlN // (111)_Si、[2110]_InAlN // [110]_Si 與 [0110]_InAlN // [1 12]_Si.

Controlling Lasing Action of Organometal Halide Proveskites [ 下載 PDF ]

Tsung-Sheng Kao, Fang-Chung Chen, Tien-Chang Lu

Solution-processed organic-inorganic perovskites are fascinating for their remarkable photo-conversion effi ciency and great potentials in the cost-effective and large-scale manufacturing of flexible optoelectronics devices. In this work, we discuss the manipulation of perovskite nanocrystal sizes and the feasible tunability of the lasing performance. Also, a promising post-processing method to promote the lasing performance of organometal halide perovskites is proposed and demonstrated. With the adding Ag and PMMA thin films, the threshold excitation power for lasing action in perovskites can be greatly reduced due to the strong exciton-plasmon coupling between the Ag and perovskite films. The advantages exhibited by the hybrid perovskite configuration would be very promising in making practical light-emitting and lasing devices.

From Quantum Hall Effect to Topological Photonics/Acoustics [ 下載 PDF ]

Ya-Wen Tsai, Jie-Luen Wu, Pi-Gang Luan

Photonic crystals, photonic band gap materials, metamaterials and topological photonics, all of these research areas concerning electromagnetic waves are inspired by some important concepts in condensed matter physics. In this article, we introduce the concepts in topological insulator and topological photonics, and discuss the possible future of the topological materials research.

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Multilayer Bandpass Filter on Liquid Crystal Polymer Substrates Using Inkjet Printing and Lamination Bonding Technologies [ 下載 PDF ]

Cheng-Lin Cho, Hsuan-ling Kao

Inkjet printing technology, unlike the traditional photolithography technique, has been adopted for digital images to direct write layered patterns into substrate. The advantages of inkjet printing are cost-efficient, fast, and environmentally friendly make it as an emerging industrial technique. Moreover, inkjet printing technology provides wider selections of substrates, particularly integrated circuit on flexible substrates. Additionally, combining inkjet printing and lamination bonding technologies achieves multilayer integrated circuit for system-on-package technologies. This study developed inkjet printing and lamination bonding technologies to realize radio frequency filters on liquid crystal polymers substrates. The process conditions including surface wettability, inkjet printing and lamination bonding parameters, and sintering temperature were examined surface morphologies and electrical properties. Based on the optimal parameters, multilayer bandpass filter was fabricated to demonstrate the inkjet printing and lamination bonding technologies.

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When a Nano-Probe Engineer Meet a New Type of AFM—a Novel Analysis Technology for Surface Property [ 下載 PDF ]

Feng-Sheng Kao, Jen-You Chu

The new type of atomic force microscopy is becoming more prevalent. The powerful functions make it easier to study physical properties of surfaces. Some information such as elastic modulus, deformation, and adhesion can be obtained at the same time without compromising highest resolution. In this study, mechanic property measurement of soft matter is conducive to biomaterials development. By modifying AFM tips with functional groups, the recognition of specific surface properties is achieved, that is molecular recognition force microscopy. Our laboratory had developed several functional tips which can distinguish hydrophilic or hydrophobic surfaces, antifouling efficacy and so on. In this study we provide a method for determining the antifouling ability of a material surface, which is based on AFM with pollutant-coated AFM probes. We also improve the anti-stick property of AFM probe and extend probe's life time, which solves the stickiness problems when scanning polymer samples. We expect this technology can significantly shorten the time of developing new materials for the manufacture and speed the implementation of the novel technology in industry.