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In this work, we present an analytical DC model for the Gallium Nimtide High Electron Mobility Transistor by taking into account the finite width of the two-dimensional electron gas (2DEG) layer. The model predicts the vertical electric field in the device, especially at the interface of AlGaN and GaN layers, electrostatic potential, and energy band diagram are also obtained by the model. The general form of Gauss's law including piezoelectric and spontaneous polarization effect is employed to obtain this model in different regions from top to bottom of the GaN-HEMT. The model solves electrostatic equations in all regions of the device including two narrow regions around the AlGaN/GaN interface with thicknesses of about 3 nm. This model demonstrates how the triangular quantum well is formed around the AlGaN/GaN interface and varies as a function of gate voltages. Using the proposed electrostatic analysis and the treatment proposed by the EPFL HEMT model, the DC current-voltage characteristics are obtained by this model. The results predicted by the model are validated with TCAD simulations and in part with the EPFL HEMT model. The proposed model facilitates the following steps toward obtaining a complete model for small signal and large signal analysis of GaN HEMT. [ABSTRACT FROM AUTHOR]

In this article, we explored the effect of a single charge trap on the charge stability diagram of the quantum-dot-based single-electron transistor. We investigated anomalies in the coulomb characteristic diagram, system energy, occupation probabilities, and quantum dot conductivity arising from the electrostatic interaction between the main dot and this charge trap. The anomalies were studied for various locations of the trap, mainly when the trap is located at the source or drain sides of the device. A significant enhancement in quantum dot conductivity was observed by bringing the main quantum dot closer to the source and drain with increased coupling capacitors. The trap, capacitively linked to the quantum dot, has two charge states, either empty or occupied by a single electron. Considering various quantum states, we solved the master equation using Fermi's golden rule to obtain tunneling rates and the matrix of tunneling coefficients. Inverting the coefficient matrix allowed us to determine the probability of each quantum state. The results of this analysis have been validated by comparing simulation results with experimental data. In conclusion, our study provides a valuable tool for detecting charge presence in a trap near a quantum dot, potentially applicable for the readout of quantum gates. [ABSTRACT FROM AUTHOR]

In this work, the electronic and spin characteristics of Janus In2X2Y and In2XYZ (X, Y, and Z = S, Se, Te) monolayers are explored. The two sides of these Janus compounds have distinct vacuum levels due to their vertical asymmetry, which causes different work functions. An emerging dipole moment alters the band alignments on both surfaces of the Janus In2X2Y structures due to electronegativity differences between various chalcogen atoms on each surface. The band structures of these monolayers with and without spin–orbit coupling (SOC) are compared. The SOC consideration opens a finite bandgap in the In2STeS, In2SSTe, In2SeTeSe, and In2SeTeTe monolayers, while demonstrating a metallic behavior without SOC. The band inversion is indicated in these monolayers using projected band structures. In addition, In2SSeTe and In2SeTeS monolayers exhibit band inversion, and In2SeTeS has the highest topological bandgap as 111 meV. [ABSTRACT FROM AUTHOR]

Comprehensive model for the insulator to metal phase transition in vanadium dioxide thin film in the presence of external electrical stimulus is proposed. This model divides the film layer into several segments and solves the Joule heating equations due to current flow and heat exchange with the environment and Poole–Frankel equation to obtain carrier concentration in response to the applied voltage, and transition is checked for each cell separately. The model follows the experimental results and exhibits both switching and hysteresis effect in planar structures and S-shaped current–voltage characteristics in sandwich metal–insulator–metal structure based on the vanadium dioxide thin film. This model shows that by reducing the vanadium dioxide layer thickness, the electric field-assisted transition plays the dominant role in the transition, and therefore, it is a promising tool for the design and analysis of vanadium dioxide structures with various electrode distances. [ABSTRACT FROM AUTHOR]

In this work, the electronic and spin characteristics of Janus In 2 X 2 Y and In 2 XYZ (X, Y, and Z = S, Se, Te) monolayers are explored. The two sides of these Janus compounds have distinct vacuum levels due to their vertical asymmetry, which causes different work functions. An emerging dipole moment alters the band alignments on both surfaces of the Janus In 2 X 2 Y structures due to electronegativity differences between various chalcogen atoms on each surface. The band structures of these monolayers with and without spin-orbit coupling (SOC) are compared. The SOC consideration opens a finite bandgap in the In 2 STeS, In 2 SSTe, In 2 SeTeSe, and In 2 SeTeTe monolayers, while demonstrating a metallic behavior without SOC. The band inversion is indicated in these monolayers using projected band structures. In addition, In 2 SSeTe and In 2 SeTeS monolayers exhibit band inversion, and In 2 SeTeS has the highest topological bandgap as 111 meV.