Related papers: Defects responsible for abnormal n-type conductivi…
High thermoelectric energy conversion efficiency requires a large figure-of-merit, zT, over a broad temperature range. To achieve this, we optimize the carrier concentrations of n-type PbTe from room up to hot-end temperatures by co-doping…
Doping properties of Bi, Cr and Ag dopants in thermoelectric and topological materials PbTe and SnTe are analyzed based on density functional theory calculations in the local density approximations and the large supercell method. In…
We apply hybrid density functional theory calculations to identify the formation energies and thermodynamic charge transition levels of native point defects, common impurities, and shallow dopants in BAs. We find that boron-related defects…
The first principles calculations (GGA) have been applied to study the crystallographic defects in $\alpha$-PbO in order to understand an origin of $n$- and $p$-type conductivity in otherwise undoped $\alpha$-PbO. It was found that…
AlFe$_2$B$_2$, a ternary transition metal boride doped with Ag, Ni, Sb, Ga, and Ge was investigated for the phase constituents, microstructure, and thermoelectric properties. The parent compound with 20\% excess Al (Al$_{1.2}$Fe$_2$B$_2$)…
In this study, we determined the effect of doping with the noble metal Ag on Ir$_2$Te$_4$ superconductors. Based on the resistivity, magnetization, and heat capacity, we explored the changes in the superconductivity and charge density wave…
We carried out X-ray diffraction and Extended X-ray Absorption Fine Structure (EXAFS) studies to investigate the origin of the low lattice thermal conductivity in BiCuSeO, and the role of silver (Ag) doping in doped samples. BiCuSeO is a…
The potential of Fe2TiSn full-Heusler compounds for thermoelectric applications has been suggested theoretically, but not yet grounded experimentally, due to the difficulty of obtaining reproducible, homogeneous, phase pure and defect free…
P mono-doped and (P, N) co-doped ZnO are investigated by the first-principles calculations. It is found that substitutive P defect forms a deep acceptor level at O site (PO) and it behaves as a donor at Zn site (PZn), while interstitial P…
Cubic boron arsenide (BAs) stands out as a promising material for advanced electronics, thanks to its exceptional thermal conductivity and ambipolar mobility. However, effective control of p- and n-type doping in BAs poses a significant…
The promise enabled by BAs high thermal conductivity in power electronics cannot be assessed without taking into account the reduction incurred when doping the material. Using first principles calculations, we determine the thermal…
The temperature dependent thermoelectric power (TEP) of boron and nitrogen doped multi-walled carbon nanotube mats has been measured showing that such dopants can be used to modify the majority conduction from p-type to n-type. The TEP of…
The properties of ferroelectric materials, such as lead zirconate titanate (PZT), are heavily influenced by the interaction of defects with domain walls. These defects are either intrinsic, or are induced by the addition of dopants. We…
Using hybrid density functional theory, we address point defects susceptible to cause charge compensation upon Mg doping of GaN. We determine the free energy of formation of the nitrogen vacancy and of several Mg-related defects. The…
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…
Achieving efficient n-type doping in AlN, a representative ultrawide bandgap (UWBG) semiconductor, remains a longstanding challenge that limits its application in high-power electronics and deep-ultraviolet optoelectronics. Conventional…
Pd site doping effect on superconductivity was investigated in quasi-one-dimensional superconductor Nb2(Pd1-xRx)0.76S5 (R=Ir, Ag) by measuring resistivity, magnetic susceptibility and Hall effect. It was found that superconducting…
Superconductivity in a doped topological insulator (TI) is a very interesting phenomenon and constitute a new finding of the modern day condensed matter physics. Here we have investigated the physical and transport properties of such an…
We present an ab initio study of dopant-dopant interactions in beryllium-doped InGaAs. We consider defect formation energies of various interstitial and substitutional defects and their combinations. We find that all…
Tuning of the electronic properties of pre-synthesized colloidal semiconductor nanocrystals (NCs) by doping plays a key role in the prospect of implementing them in printed electronics devices such as transistors, and photodetectors. While…