CNSi/MXene/CNSi: Unique Structure with Specific Electronic Properties for Nanodevices

Abstract

nanodevices and the next generation of integrated circuits (IC). [3,[6][7][8] For example, graphene has been widely studied for its application into nanodevices because of its excellent electron mobility. [9][10][11][12] But, how to achieve semiconducting one for IC on large scale is still a challenging issue. [13,14] 2D transitional metal dichalcogenides (TMDs) have also attracted extensive attention for their applications into nanodevices because of the high stability and intrinsic semiconducting property. [6,15,16] For example, MoS 2 -based nano Field-Effect Transistor (FET) had been experimentally fabricated. [17] However, additional electrodes have to be added into the device, leading to extra cost, contact resistance [18][19][20][21] and difficulty for commercial application.It is well-known that a device is composed of semiconducting and metallic parts. To construct the device with 2D materials, we need to stack 2D materials with different conducting characteristics together in most cases to form heterostructures, where the 2D materials are mainly bonded together by van der Waals (vdW) interaction. [22][23][24][25] For example, MoS 2 and graphene were combined by vdW force to form a heterostructure for application in nanodevices. [6,26] However, the process not only results in complicity of fabrication, but also the uncertainty of device's 2D materials have been interesting for applications into nanodevices due to their intriguing physical properties. In this work, four types of unique structures are designed that are composed of MXenes and C/N-Si layers (CNSi), where MXene is sandwiched by the CNSi layers with different thicknesses, for their practical applications into integrated devices. The systematic calculations on their elastic constants, phonon dispersions, and thermodynamic properties show that these structures are stable, depending on the composition of MXene. It is found: 1) different from MXene or N-functionalized MXene (M 2 CN 2 ), SiN 2 /M 2 X/SiN 2 possess new electronic properties with free carriers only in the middle, leading to 2D free electron gas; 2) CNSi/MXene/ CNSi shows an intrinsic Ohmic semiconductor-metal-semiconductor (S-M-S) contact, which is potential for applications into nanodevices; and 3) O/M 2 C/ SiN 2 and N/M 2 C/OSiN are also stable and show different electronic properties, which can be semiconductor or metal as a whole depending on the interface. A method is further proposed to fabricate the 2D structures based on the industrial availability. The findings may provide a novel strategy to design and fabricate the 2D structures for their application into nanodevices and integrated circuits.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.202101482.

LaOMS2 (M = Ti, V, and Cr): novel crystal spin valves without contact

“…To match the lattice in the junction, 2D materials inevitably experience strain, which may affect their electronic properties. [38][39][40][41] Thus, we firstly tested the electronic structure of LaOCrS 2 under strain. We see that LaOCrS 2 remains a halfmetal/conductor in the FM/inter-AFM state under strain (Fig.…”