In this work, a hybrid simulation technique is introduced for the electrothermal study of two-dimensional GaN-on-SiC high electron mobility transistor. Detailed and phonon transport considered by coupled Monte Carlo simulations in transistor region. For regions away from transistor, conventional Fourier's law used thermal analysis to minimize computational load. This strategy can incorporate physical phenomena over multiple length scales, including generation hot electrons conduction...

In the past two decades, phonon transport within nanoporous thin films has attracted enormous attention for their potential applications in thermoelectrics and thermal insulation. Various computational studies have been carried out to explain conductivity reduction these films. Considering classical size effects, lattice can be predicted assuming diffusive pore-edge scattering of phonons bulk mean free paths. Following this, detailed simulated a given porous structure find [Hao et al., J....

Abstract In recent years, nanoporous Si films have been widely studied for thermoelectric applications due to the low cost and earth abundance of Si. Despite many encouraging results, inconsistency still exists among experimental theoretical studies reduced lattice thermal conductivity varied patterns. addition, divergence can also be found reported data, difference in sample preparation measurement setups. this work, systematic measurements are carried out on thin with pore pitches order...

Tailoring thermal properties with nanostructured materials can be of vital importance for many applications.Generally classical phonon size effects are employed to reduce the conductivity, where strong scattering by interfaces or boundaries dramatically suppress heat conduction.When these arranged in a periodic pattern, coherent phonons may have interference and modify dispersion, leading reduced conductivity.Such transport has been widely studied superlattice films recently emphasized...

Abstract A bis(phenylamino)disulfide was prepared through the reaction of S 2 Cl with aniline, and its configuration confirmed elemental analysis, Fourier transform infrared (FTIR), Raman (FT‐Raman), 1 H NMR spectroscopy. novel conducting polymer, poly[bis(phenylamino)disulfide] (PPAD), synthesized from by both chemical electrochemical polymerization. The structure this in which side‐chain disulfide bonds were linked to nitrogen atoms main‐chain polyaniline, characterized FTIR, FT‐Raman, gel...

Nanocarbon materials have been widely used for nanoelectronics and energy-related applications. In this work, composite films consisting of reduced graphene oxides (rGOs) single-wall carbon nanotubes (SWCNTs) are synthesized studied their in-plane thermal conductivities. Different from pristine or with decreased conductivities above 300 K, the these found to follow trend specific heat 100 400 i.e., monotonously increasing at elevated temperatures. Such a can often be within amorphous solids...

In recent years, 3-D GaN-based transistors have been intensively studied for their dramatically improved performance. However, thermal analysis of such devices is often oversimplified using the conventional Fourier's law in simulations. this aspect, accurate temperature predictions can be achieved by coupled phonon and electron Monte Carlo (MC) simulations that track movement scattering individual phonons electrons. Based on these MC transistor region rest chip, electrothermal are carried...

Concave structure of Cu₂O truncated microcubes with {100} facets etched the assistance air and PVP.

In recent years, hierarchical structures have been intensively studied as an effective approach to tailor the electron and phonon transport inside a bulk material for thermoelectric applications. With atomic defects nano- micro-scale in material, lattice thermal conductivity can be effectively suppressed across whole spectrum, while maintaining or somewhat enhancing electrical properties. For general materials with superior properties, high performance achieved using minimize conductivity....

Nanoporous materials (sub-10 nm in diameter) have potential applications chips, biosensors, thermoelectrics, desalination and other fields due to their large surface-to-volume ratio. Thermal annealing is a preferred technique precisely control the ultra-fine nanopore size. Here, 3D morphological evolution of membrane with periodic nanopores by thermal studied. It found that determined combination thickness, initial radius length porous pattern, rather than previously suggested ratio between...

For thermoelectric applications, $\mathrm{Si}$ thin films with periodic circular pores have been intensively studied because of the low price and earth abundance $\mathrm{Si}$. In this work, a different nanoporous pattern is investigated for its potential benefit, i.e., film nanoslots. Inside such structures, neck between adjacent nanoslots functions as nanorestriction to suppress phonon transport, leading dramatically reduced lattice thermal conductivity. When width still longer than mean...

Additive manufacturing (AM) process is an ideal way to rapidly prototype freeform optics. We present a new precision additive optics (AFOM) method using pulsed infrared laser thermally cure optical silicones. To achieve the tight surface requirements, curing volume pixel (voxel) of AM should be precisely controlled. have developed opto-thermal-chemical-coupled multiphysics model simulate and predict shape size cured polymer. Single-point experiments were conducted Q-switched fiber with...

In this work, high-temperature annealing above 1073 K has been carried out to study the possible shape change of nanoporous Si thin films.Under 1273 K, it is found that pore size can still be largely maintained when film on a SiO /Si substrate.2 However, significantly shrink suspended.The contrast suggests substrate play an 2 important role in maintaining patterns at high temperature.This finding for applications these porous films, such as thermoelectric power generation.

In recent years, nanoporous Si films have been intensively studied for their potential applications in thermoelectrics and the thermal management of devices. To minimize conductivity, ultrafine patterns are required but smallest structure size is largely limited by spatial resolution employed nanofabrication techniques. Along this line, an effectively smaller characteristic length a film can be achieved with offset nanoslot patterns. Compared periodic circular pores, pattern achieve even...

Electron transport within nanostructures can be important to varied engineering applications, such as thermoelectrics and nanoelectronics. In theoretical studies, electron Monte Carlo simulations are widely used an alternative approach solving the Boltzmann equation, where energy-dependent scattering, exact structure shape, detailed electric field distribution fully incorporated. this work, employed predict electrical conductivity of periodic nanoporous Si films that have been studied for...

We have studied the valence effects on stability of Stone-Wales (SW) defect in some typical two-dimensional honeycomb crystals containing group-IV, V, and VI elements employing density functional theory. The energetics involved an in-plane formation process SW defects pristine substitutionally doped materials is simulated. are stable a rotation angle about 90 degree group-IV materials. They may become less with smaller group-V seem difficult to exist group-VI Group-VI doping help eliminate...

At micro- to nano-scales, classical size effects in heat conduction play an important role suppressing the thermal transport process. Such occur when characteristic lengths become commensurate mean free paths (MFPs) of carriers that are mainly phonons for nonmetallic crystals. Beyond existing experimental efforts on thin films using laser-induced gratings, this work provides complete theoretical analysis a new approach extract effective phonon MFP distribution in-plane within film or...