Following a short historical retrospective, a survey of AIIIBv materials research is presented. Potentiality of the main techniques (VPE, LPE and MBE) and material systems (AIGaAs, InGaAs) is assessed with respect to requirements posed by device manufacture. Major emphasis is placed upon the discussion of modern trends in heterostructure devices for optoelectronics, such as injection lasers, light-emitting diodes, solar cells, detectors etc. Other topics, such as Gunn diodes, avalanche-drift diodes and HF transistors, are also covered. 相似文献
A conductive tip in an atomic force microscope (AFM) has extended the capability from conventional topographic imaging to electrical surface characterization. The conductive tip acts as a voltage electrode to provide stimuli and monitor electrical surface properties. In this review article, we have organized the AFM electrical techniques based on whether the electrical properties are monitored at the cantilever tip or across the sample. Furthermore, the techniques are organized based on probe detection signal. A number of acronyms are used in the literature, and the more commonly used ones are identified. The principle of each technique is described, and representative applications are presented. A better understanding of the spectrum of techniques should serve as the driver to expand the application of electrical techniques to study interdisciplinary phenomena at the nanoscale. 相似文献
Two dimensional crystalline materials have attracted much attentions due to the establishment of heterostructure that can adjust their electrical and optical properties, and have potential applications in lasers, light-emitting diodes, solar cells and high mobility transistors. And the interface engineering is an effective route to tune structural and electrical properties in semiconductor heterostructures. In this study, the electronic structure, charge transport and optical properties of monolayer caesium bromide and black phosphorus (CsBr/BP) heterostructure are calculated by the first principle based on density functional theory (DFT). It was found that the characteristics of electronic band structures of the monolayer CsBr and BP remain in the heterostructure, and the effective mass and carrier mobility are highly anisotropic. When the heterostructure is uniaxially stretched, the mobility of electron is greater than that of the hole, while the biaxial stretching is just the opposite, the mobility of hole is greater than that of the electron. In addition, compared with the CsBr monolayer, the light absorption of the heterostructure is significantly enhanced, especially in the infrared, indicating that the CsBr/BP heterostructure can be well applied to photovoltaic devices in the future. 相似文献
In this article, we review advances in experimental techniques for the electrical characterization of artificial mesostructures from nanometer to micrometer size. As the scale of electronic devices is rapidly approaching the 100-nm benchmark, new tools are becoming necessary to study and characterize them. We are also at a point where new tools to fabricate these devices are becoming increasingly relevant. We discuss the various characterization techniques applicable to objects of this scale, with particular emphasis on scanned probe methods. 相似文献
This work elucidates the role of the Schottky junction in the electronic transport of nanometer-scale transistors. In the example of Schottky barrier silicon nanowire field effect transistors, an electrical scanning probe technique is applied to examine the charge transport effects of a nanometer-scale local top gate during operation. The results prove experimentally that Schottky barriers control the charge carrier transport in these devices. In addition, a proof of concept for a reprogrammable nonvolatile memory device based on band bending at the Schottky barriers will be shown. 相似文献
Abstract This paper describes the recent progress in research and development of fiber optics in Japan. A review is presented of recent developments in fiber manufacturing, cabling, and fiber splicing. Experimental results are given for an optical communication system with optoelectronic components. Theoretical analysis and fundamental experiments are not included, nor are research activities in such devices as lasers or in such applications as those in medical fields. Transmission characteristics of optical fibers—in particular loss and pulse spreading—are assessed from the viewpoint of their structures. Various methods of fiber strengthening and structuring cables are described from the viewpoint of mechanical strength. Coupling efficiencies of detachable connectors and methods of permanent fiber splicing are described. Experimental results on optical fiber communication systems are presented and coupling techniques between a light source and an optical fiber are described. 相似文献
In this paper we report two types of micro devices based on Pb(Zr, Ti)O3 (PZT) thin films for improving the throughput of scanning force microscopy (SFM) or data storage using SFM. One is a piezoelectric cantilever array integrated with force sensor as well as z-actuator on each cantilever for parallel operation. The 125-μm-long PZT micro cantilever with a natural resonant frequency of 189 kHz has a high actuation sensitivity of 75 nm/V. Independent parallel images using two cantilevers of the array were obtained. The other is a novel micro-SFM device that is expected to replace the cantilever, the deflection detection unit, and the macro-fabricated scanner which is the bottle neck limiting the single probe acquisition rate. The bridge-structured device has shown a microscopy sensitivity of 0.32 nA/nm in vertical direction and actuation abilities of 70-80nm/±V in the lateral direction. 相似文献
Graded barrier quantum well heterostructure (GBQWH) broad area lasers have been shown to be capable of high power pulsed and cw operation. In this article, we consider several operational characteristics and design issues associated with broad area graded barrier quantum well heterostructure lasers grown by metalorganic chemical vapor deposition. In particular, the effect of junction heating on emission wavelength for cw device operation and the effects of various buffer layer structures on the material properties and device characteristics of GBQWH structures are addressed. Typical results for high power operation of uncoated broad area laser diodes are also outlined. 相似文献
Graded barrier quantum well heterostructure (GBQWH) broad area lasers have been shown to be capable of high power pulsed and cw operation. In this article, we consider several operational characteristics and design issues associated with broad area graded barrier quantum well heterostructure lasers grown by metalorganic chemical vapor deposition. In particular, the effect of junction heating on emission wavelength for cw device operation and the effects of various buffer layer structures on the material properties and device characteristics of GBQWH structures are addressed. Typical results for high power operation of uncoated broad area laser diodes are also outlined. 相似文献
Dynamic charge carriers play a vital role in active photonic quantum/nanodevices, such as electrically pumped semiconductor lasers. Here we present a systematic experimental study of gain‐providing charge‐carrier distribution in a lasing interband cascade laser. The unique charge‐carrier distribution profile in the quantum‐well active region is quantitatively measured at nanometer scales by using a noninvasive scanning voltage microscopy technique. Experimental results clearly confirm the accumulation and spatial segregation of holes and electrons in the beating heart of the device. The measurement also shows that the charge‐carrier density is essentially clamped in the presence of stimulated emission at low temperatures. The threshold charge‐carrier density exhibits a linear but fairly weak temperature dependence, in contrast to the exponential temperature dependence of the threshold current. The experimental approach will lead to a deeper understanding of fundamental processes that govern the operation and performance of nanoelectronic devices, quantum devices and optoelectronic devices.
We have numerically analyzed some thermal characteristics of cw long wavelength surface emitting lasers with epitaxially grown semiconductor distributed Bragg reflectors (DBRs). It was shown that the device thermal resistance for GaAs/AlAs DBRs epitaxially fused to GalnAsP/InP emitting layers is 1/3 of that for GalnAsP/InP DBRs and almost comparable to that for the optimum dielectric cavity. The threshold current lower than 10 mA and the electrical resistance lower than 100 Ω are necessary to obtain the cw operation beyond room temperature 相似文献
A high uniformity of sheet resistance was achieved in the double-channel (DC) Al0.82In0.18N/GaN heterostructure by lowering the interface roughness scattering effect. The variation of the AlInN/GaN interface roughness as a key factor influenced the uniformity of the sheet resistance. In the DC heterostructure, the distribution of the two dimension electron gas (2DEG) was modified to reduce interface roughness scattering effect. As a result, the uniformity of the sheet resistance was enhanced, and the nonuniformity of the sheet resistance in the DC Al0.82In0.18N/GaN could be reduced to 0.7% after structure optimization. 相似文献
Kelvin probe force microscopy (KPFM) is a tool that enables nanometer-scale imaging of the surface potential on a broad range of materials. KPFM measurements require an understanding of both the details of the instruments and the physics of the measurements to obtain optimal results. The first part of this review will introduce the principles of KPFM and compare KPFM to other surface work function and potential measurement tools, including the Kelvin probe (KP), photoemission spectroscopy (PES), and scanning electron microscopy (SEM) with an electron beam induced current (EBIC) measurement system. The concept of local contact potential difference (LCPD), important for understanding atomic resolution KPFM, is discussed. The second part of this review explores three applications of KPFM: metallic nanostructures, semiconductor materials, and electrical devices. 相似文献