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41.
Electronic and optical properties of 3N-doped graphdiyne/MoS2 heterostructures tuned by biaxial strain and external electric field 下载免费PDF全文
The construction of van der Waals (vdW) heterostructures by stacking different two-dimensional layered materials have been recognised as an effective strategy to obtain the desired properties. The 3N-doped graphdiyne (N-GY) has been successfully synthesized in the laboratory. It could be assembled into a supercapacitor and can be used for tensile energy storage. However, the flat band and wide forbidden bands could hinder its application of N-GY layer in optoelectronic and nanoelectronic devices. In order to extend the application of N-GY layer in electronic devices, MoS2 was selected to construct an N-GY/MoS2 heterostructure due to its good electronic and optical properties. The N-GY/MoS2 heterostructure has an optical absorption range from the visible to ultraviolet with a absorption coefficient of 105 cm-1. The N-GY/MoS2 heterostructure exhibits a type-Ⅱ band alignment allows the electron-hole to be located on N-GY and MoS2 respectively, which can further reduce the electron-hole complexation to increase exciton lifetime. The power conversion efficiency of N-GY/MoS2 heterostructure is up to 17.77%, indicating it is a promising candidate material for solar cells. In addition, the external electric field and biaxial strain could effectively tune the electronic structure. Our results provide a theoretical support for the design and application of N-GY/MoS2 vdW heterostructures in semiconductor sensors and photovoltaic devices. 相似文献
42.
Jui‐Fen Chang Michael C. Gwinner Mario Caironi Tomo Sakanoue Henning Sirringhaus 《Advanced functional materials》2010,20(17):2825-2832
Solution processing of polymer semiconductors provides a new paradigm for large‐area electronics manufacturing on flexible substrates, but it also severely restricts the realization of interesting advanced device architectures, such as lateral heterostructures with defined interfaces, which are easily accessible with inorganic materials using photolithography. This is because polymer semiconductors degrade, swell, or dissolve during conventional photoresist processing. Here a versatile, high‐resolution photolithographic method is demonstrated for patterning of polymer semiconductors and exemplify this with high‐performance p‐type and n‐type field‐effect transistors (FETs) in both bottom‐ and top‐gate architectures, as well as ambipolar light‐emitting field‐effect transistors (LEFETs), in which the recombination zone can be pinned at a photolithographically defined lateral heterojunction between two semiconducting polymers. The technique therefore enables the realization of a broad range of novel device architectures while retaining optimum materials performance. 相似文献
43.
Kristian Berland 《Superlattices and Microstructures》2011,50(4):411-418
A general, system-independent, formulation of the parabolic Schrödinger–Poisson equation is presented for a charged hard wall in the limit of complete screening by the ground state. It is solved numerically using iteration and asymptotic boundary conditions. The solution gives a simple relation between the band bending and sheet charge density at an interface. Approximative analytical expressions for the potential profile and wave function are developed based on properties of the exact solution. Specific tests of the validity of the assumptions leading to the general solution are made. The assumption of complete screening by the ground state is found be a limitation; however, the general solution provides a fair approximate account of the potential profile when the bulk is doped. The general solution is further used in a simple model for the potential profile of an AlN/GaN barrier structure. The result compares well with the solution of the full Schrödinger–Poisson equation. 相似文献
44.
势函数是在平衡态统计物理中应用得十分成功的理论,将势函数理论推广到非平衡系统是非平衡态统计物理的一项十分重要的任务。本文综述了非平衡态势函数理论的一个重要方面,即利用对随机过程的研究来建立系统的势函数,本文阐述了非平衡系统势函数的定义和概念;论证势函数在系统演化过程中的单调性质;详细介绍了各种计算非平衡势函数的方法;同时介绍了利用势函数解析地研究在噪声作用下的非线性系统的非定态演化行为。整个研究包含了一维和多维系统的广泛系统。 相似文献
45.
46.
The coherency state of MOCVD grown InGaAsP/InP double-heterostructure wafers was examined and their effects on the structural
properties were determined in this study. Lattice mismatches were measured using {511} asymmetric and (400) symmetric x-ray
reflections. The chemical lattice misfit and the elastic strain were also calculated. Misfit dislocations were examined by
both x-ray topography and photoluminescence imaging. The x-ray full width at half maximum (FWHM) varied with the degree of
mismatch. The largest FWHM was obtained for samples containing the misfit dislocations. It was found that FWHM is influenced
not only by the plastic deformation, but also by the elastic strain. To model the dependence of the FWHM, the radius of curvature
was measured, and its contribution to the x-ray line broadening was calculated. Also, the contribution from misfit dislocations
was taken into account. This model assumes that the dislocations are planar and interact weakly with each other. Good agreement
between measured and calculated values was obtained. Thus, it is concluded that the major contribution to x-ray line broadening
ofelastically strained sample is the lattice curvature induced by misfit strain, and that the dominant factor affecting x-ray FWHM ofplastically deformed sample is lattice relaxation induced by misfit dislocation. 相似文献
47.
The electromodulation method of photoreflectance (PR) is becoming an important tool for the characterization of semiconductors,
semiconductor interfaces and semiconductor microstructures such as superlattices, quantum wells, multiple quantum wells and
heterojunctions. Since PR is contactless, requires no special mounting of the sample and can be performed in a variety of
transparent ambients it can be utilized for in-situ monitoring of growth at elevated temperatures, in-situ elevation at 300K
before the samples are removed from the growth/processing chamber as well as convenient ex-situ characterization. This invited
article discusses some recent uses of PR to measure (a) the direct gap (and spin-orbit split component) of InP up to 600°
C, (b) strains in Si at the Si/SiO2 interface, (c) changes in the surface Fermi level of GaAs caused by photowashing, (d) quantized intersubband transitions
in a GaAs/Gao0.82Al0.18As multiple quantum well and (e) two-dimensional electron gas effects in selectively dopedn-Gao.7Alo.3As/ GaAs heterostructures. 相似文献
48.
In this paper, we will present our recent research on the growth and characterization of some Si-based heterostructures for
optical and photonic devices. The heterostructures to be discussed are ZnO nanorods on Si, SiO2, and other substrates such as SiN and sapphire. We will also consider strained Si1−xGex/Si heterostructures for Si optoelectronics. The performance and functionality extension of Si technology for photonic applications
due to the development of such heterostructures will be presented. We will focus on the results of structural and optical
characterization in relation to device properties. The structural characterization includes x-ray diffraction for assessment
of the crystallinity and stress in the films and secondary ion mass spectrometry for chemical analysis. The optical properties
and electronic structure were investigated by using photoluminescence. The device application of these thin film structures
includes detectors, lasers, and light emitting devices. Some of the Si-based heterostructures to be presented include devices
emitting and detecting up to the blue-green and violet wave lengths. 相似文献
49.
N. Duhamel K. Daoud-Ketata B. Descouts P. Krauz M. Gauneau S. Godefroy 《Journal of Electronic Materials》1986,15(6):377-382
The aim of this work is to study the electrical properties of Mg24 and Zn64 implanted and annealed samples (semi-insulating GaAs substrates,n
+ doped GaAs epilayers, GaAs-GaAlAs heterostructures) with the final objective of realizing the contact region for the p-type
base layer of heterojunction bipolar transistor (HBT). We show that, for HBT applications, Mg+ is a more suitable candidate because its characteristics (depth, concentration) are easier to control: they are not very
sensitive to doping level and composition of different layers. Low specific contact resistivity (<10-5Ωcm2) have been obtained with Au-Mn alloy on Mg+ implanted GaAs. 相似文献
50.
Hui Zeng Yao Wen Lei Yin Ruiqing Cheng Hao Wang Chuansheng Liu Jun He 《Frontiers of Physics》2023,18(5):53603
Two-dimensional (2D) transition metal dichalcogenides (TMDs) with fascinating electronic energy band structures, rich valley physical properties and strong spin–orbit coupling have attracted tremendous interest, and show great potential in electronic, optoelectronic, spintronic and valleytronic fields. Stacking 2D TMDs have provided unprecedented opportunities for constructing artificial functional structures. Due to the low cost, high yield and industrial compatibility, chemical vapor deposition (CVD) is regarded as one of the most promising growth strategies to obtain high-quality and large-area 2D TMDs and heterostructures. Here, state-of-the-art strategies for preparing TMDs details of growth control and related heterostructures construction via CVD method are reviewed and discussed, including wafer-scale synthesis, phase transition, doping, alloy and stacking engineering. Meanwhile, recent progress on the application of multi-functional devices is highlighted based on 2D TMDs. Finally, challenges and prospects are proposed for the practical device applications of 2D TMDs. 相似文献