Related papers: Phonon transport unveils the prevalent point defec…
We report accurate energetics of defects introduced in GaN on doping with divalent metals, focussing on the technologically important case of Mg doping, using a model which takes into consideration both the effect of hole localisation and…
The semiconducting behaviour and optoelectronic response of gallium nitride is governed by point defect processes, which, despite many years of research, remain poorly understood. The key difficulty in the description of the dominant…
We study the formation energies of native point defects in GaN through density-functional theory. In our first-principles scheme, the band edges are positioned in accord with hybrid density functional calculations, thus yielding a band-gap…
Determining defect types and concentrations remains a big challenge of semiconductor materials science. By using ab-initio thermal conductivity calculations we reveal that Ni/vacancy antisites, and not the previously claimed Sn/Zr…
In order to study the novel gas detection or sensing applications of gallium nitride monolayer (GaN-ML), we mainly focused on the structural, energetic, electronic and magnetic properties of toxic gas molecules (CO, NO) adsorbed on…
Understanding phonon transport properties in defect-laden AlN is important for their device applications. Here, we construct a machine-learning potential to describe phonon transport with $ab$ $initio$ accuracy in pristine and defect-laden…
Defects such as vacancies and impurities could have profound effects on the transport properties of thermoelectric materials. However, it is usually quite difficult to directly calculate the thermoelectric properties of defect-containing…
Understanding heat conduction in defective silicon is crucial for electronics and thermoelectrics. Conventional understanding relies on phonon gas picture, treating defects as scattering centers that reduce phonon lifetimes without altering…
To develop effective thermal management strategies for GaN transistors, it is essential to accurately predict the device junction temperature. Since the width of the heat generation in the devices is comparable to phonon mean free paths of…
Erbium (Er) doped GaN has been studied extensively for optoelectronic applications, yet its defect physics is still not well understood. In this work, we report a first-principles hybrid density functional study of the structure,…
The study of phonon coupling in doped semiconductors via electrical transport measurements is challenging due to unwanted temperature-induced effects such as dopant ionisation and parallel conduction. Here, we study phonon scattering in 2D…
Gallium nitride (GaN) is a typical wide-bandgap semiconductor with a critical role in a wide range of electronic applications. Ballistic thermal transport at nanoscale hotspots will greatly reduce the performance of a device when its…
We report on the direct measurement of two-dimensional sheet charge density dependence of electron transport in AlGaN/GaN high electron mobility transistors. Pulsed IV measurements established increasing electron velocities with decreasing…
Doping problems in GaN and in AlGaN alloys are addressed on the basis of state-of-the-art first-principles calculations. For n-type doping we find that nitrogen vacancies are too high in energy to be incorporated during growth, but silicon…
Oxygen is the most common unintentional impurity found in GaN. We study the interaction between substitutional oxygen (ON) and the gallium vacancy (VGa) to form a point defect complex in GaN. The formation energy of the gallium vacancy is…
Buffer leakage is an important parasitic loss mechanism in AlGaN/GaN HEMTs and hence various methods are employed to grow semi-insulating buffer layers. Quantification of carrier concentration in such buffers using conventional capacitance…
Transport measurements have revealed several exotic electronic properties of graphene. The possibility to influence the electronic structure and hence control the conductivity by adsorption or doping with adatoms is crucial in view of…
We present a general coupled electron-phonon Boltzmann transport equations (BTEs) scheme designed to capture the mutual drag of the two interacting systems. By combining density functional theory based first principles calculations of…
We present a time-resolved optical study of the dynamics of carriers and phonons in Ga_{1-x}Mn_{x}As layers for a series of Mn and hole concentrations. While band filling is the dominant effect in transient optical absorption in…
The present study examines the electronic transport characteristics of amorphous semiconductors through TOF measurements and numerical simulations. The primary objective is to determine the DOS in amorphous selenium (a-Se) and to assess the…