Applications Of Low-dimensional Materials Research Articles

Recent advances in wide-spectrum photodetectors based on low-dimensional semiconductors

Compared with three-dimensional semiconductors, low-dimensional (LD) semiconductors have unique atomic arrangements and excellent optical and electrical characteristics, such as high absorptivity, mechanical flexibility, and absence of dangling bonds on the surface. With these advantages, LD semiconductors are considered as a kind of promising materials in the field of photodetection. However, the applications of LD materials are limited by their dimensional constraint, large dark current, high noise, low quantum efficiency, slow response speed, and other characteristics. In this paper, the recent advances in wide-spectrum photodetectors in the ultraviolet to infrared spectrum are reviewed. The working mechanisms and performance parameters of photodetectors are described. Specific research examples based on wide-spectrum photodetectors are reviewed based on three aspects, namely the structure of photodetectors, their response mechanisms, and important performance indicators. Furthermore, the challenges in improving the performance of wide-spectrum photodetectors are discussed, along with the prospective development trends of wide-spectrum photodetectors.

Selection of Low Dimensional Material Alternatives to Silicon for Next Generation Tunnel Field Effect Transistors

This paper presents a method-based investigation on the application of low dimensional materials like graphene, carbon nanotube (CNT), transition metal dichalcogenides (TMDCs) in tunnel field effect transistors (TFETs) for high on-current requirements. Three multi-criteria decision making methods (MCDM) are employed to arrive at a consensus on the appropriate material. The Ashby technique, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and VlseKriterijumska Optimazicija I Kompromisno Resenjein in Serbian (VIKOR) are utilized using constraints which decide a TFET’s performance. In order to select the material, dominant parameters have been included in the formulation which includes intrinsic material properties like the band gap, dielectric constant and electron effective mass along with an extrinsic parameter, namely, the on-state current to the off-state current ratio. The analysis demonstrates a remarkable agreement between the results of Ashby, TOPSIS and VIKOR methods, and concludes that carbon nanotube (CNT) has the most potential amongst all the candidates to be employed in the next generation TFETs.

Two-Dimensional (001) LaAlO3/SrTiO3 Heterostructures with Adjustable Band Gap and Magnetic Properties.

Very recently, freestanding crystalline perovskite films as thin as a single unit cell have been successfully synthesized, which expands the opportunities for research and applications of low-dimensional materials with novel functionalities. In this work, we constructed a series of two-dimensional (2D) (001) LaAlO3/SrTiO3 heterostructures and systematically investigated their atomic and electronic properties by means of first-principles calculations. Our results show that (1) nonstoichiometry leads to ferromagnetism at the interfaces of the systems; (2) half-metallicity can be realized by introducing slight hole-doping; and (3) a semiconductor-to-metal transition can be triggered by applying a moderate (within 3%) out-of-plane strain. Besides, based on in-depth analysis of the electronic structures, we propose that the orbital hybridization of interfacial O and Ti atoms may play a crucial role in determining the above interesting phenomena. Our findings are expected to stimulate further experimental researches on the related 2D perovskite heterostructures and to be beneficial for the design of new multifunctional electronic devices.

Determining the Degree of [001] Preferred Growth of Ni(OH)₂ Nanoplates.

Determining the degree of preferred growth of low-dimensional materials is of practical importance for the improvement of the synthesis methods and applications of low-dimensional materials. In this work, three different methods are used to analyze the degree of preferred growth of the Ni(OH)2 nanoplates synthesized without the use of a complex anion. The results suggest that the preferred growth degree of the Ni(OH)2 nanoplates calculated by the March parameter and the expression given by Zolotoyabko, which are based on the analysis and texture refinement of the X-ray diffraction pattern, are in good accordance with the results measured by SEM and TEM imaging. The method using the shape function of crystallites is not suitable for the determination of the preferred growth degree of the Ni(OH)2 nanoplates. The method using the March parameter and the expression given by Zolotoyabko can be extended to the analysis of block materials.

Tuning Surface Properties of Low Dimensional Materials via Strain Engineering.

The promising and versatile applications of low dimensional materials are largely due to their surface properties, which along with their underlying electronic structures have been well studied. However, these materials may not be directly useful for applications requiring properties other than their natal ones. In recent years, strain has been shown to be an additionally useful handle to tune the physical and chemical properties of materials by changing their geometric and electronic structures. The strategies for producing strain are summarized. Then, the electronic structure of quasi-two dimensional layered non-metallic materials (e.g., graphene, MX2, BP, Ge nanosheets) under strain are discussed. Later, the strain effects on catalytic properties of metal-catalyst loaded with strain are focused on. Both experimental and computational perspectives for dealing with strained systems are covered. Finally, an outlook on engineering surface properties utilizing strain is provided.