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1. #MULLIKEN POPULATION CHARGE TRANSFER QUANTUMWISE SIMULATOR#
2. #MULLIKEN POPULATION CHARGE TRANSFER QUANTUMWISE FREE#

These subtle attributes have encouraged the application of vdWHs as a platform for constructing sophisticated nano-devices such as field-effect transistors (FETs), 8, 9, 10 tunnel devices, 11, 12 photo-detector, 13 light-emitting diode, 14, 15 solar cell, 16 flexible electronics 10 etc.Īmong all types of FET devices studied theoretically or fabricated for experimental and commercial purposes, the MIS (metal–insulator–semiconductor) structure, which substitutes metal (or highly doped polysilicon) by semi-metallic graphene, SiO 2 (or high-K gate dielectric) by insulating h-BN, and Si by MoS 2, could pave the way for realizing thinnest possible FET.

#MULLIKEN POPULATION CHARGE TRANSFER QUANTUMWISE FREE#

The hetero-interfaces thus produced, are atomically sharp and self-passivated, i.e., free of dangling bonds and trapped charges. 5 In such vertically stacked van der Waal’s heterostructures (vdWH), 6 the individual layers are ‘glued’ together by weak van der Waal’s (vdW) forces of interaction, 7 whereas the in-plane atoms are strongly bound by covalent or ionic bonds. Since these new materials inherit diverse electronic and opto-electronic properties, novel device functionalities could be engineered from such atomically thin interfaces. Advancement of nanofabrication technology has opened up the possibility of realizing interfaces at their ‘ultimate-limit’ by vertical stacking 1, 2, 3 or parallel stitching 4 of 2D materials. Since the proposed modeling framework translates atomic level phenomena (e.g., band-gap opening in graphene or introduction of semiconductor doping) to a circuit performance metric (e.g., frequency of a ring oscillator), it may provide solutions for the application and optimization of new materials.įunctionality of an electronic device originates from the interfacial properties of its constituent materials.

#MULLIKEN POPULATION CHARGE TRANSFER QUANTUMWISE SIMULATOR#

Finally, the models are implemented in a circuit simulator to facilitate design and simulation of integrated circuits. The energy band-structure obtained is then used to develop a physics-based compact device model to assess transistor characteristics. In a multi-scale modeling approach, we start with the development of a first principles-based atomistic model to study fundamental electronic properties and charge transfer at the atomic level. Here, we propose an ‘atom-to-circuit’ modeling framework for all-2D MISFET (metal–insulator–semiconductor field-effect transistor), which has recently been conceived by vertically stacking semiconducting transition metal dichalcogenide (e.g., MoS 2), insulating hexagonal boron nitride and semi-metallic graphene. Thus, first principles-based models that enable systematic performance evaluation of emerging 2D materials at device and circuit level are in great demand. In the semiconductor industry, however, the process of integration for any new material is expensive and complex. Vertical stacking of heterogeneous two-dimensional (2D) materials has received considerable attention for nanoelectronic applications.