Related papers: Theoretical evidence for efficient p-type doping o…
Impurity levels and formation energies of acceptors in wurtzite GaN are predicted ab initio. Be_Ga is found to be the shallow (thermal ionization energy $\sim$ 0.06 eV); $Mg_{Ga}$ and $Zn_{Ga}$ are mid-deep acceptors (0.23 eV and 0.33 eV…
The hot-wall metal-organic chemical vapor deposition (MOCVD), previously shown to enable superior III-nitride material quality and high performance devices, has been explored for Mg doping of GaN. We have investigated the Mg incorporation…
Ga2O3 is being actively explored for high-power and high-temperature electronics, deep-ultraviolet optoelectronics, and other applications. Efficient n-type doping of Ga2O3 has been achieved, but p-type doping faces fundamental obstacles…
The effect of modulation doping by Be on the ferromagnetic properties of Ga(1-x)Mn(x)As is investigated in Ga(1-x)Mn(x)As/Ga(1-y)Al(y)As heterojunctions and quantum wells. Introducing Be acceptors into the Ga(1-y)Al(y)As barriers leads to…
First-principles density functional simulations were employed to investigate the geometries, electrical properties, and hyperfine structures of various beryllium-doped diamond configurations, including interstitial (Be$_i$), substitutional…
The electrical and magnetic properties of p-type cubic (Ga,Mn)N thin films grown by plasma-assisted molecular beam epitaxy are reported. Hole concentrations in excess of 1018 cm-3 at room temperature are observed. Activated behaviour is…
GeSn is a promising group-IV semiconductor material for on-chip Si photonics devices and high-mobility transistors. These devices require the use of doped GeSn regions, achieved preferably in-situ during epitaxy. From the electronic valence…
We present a theoretical study of (Ga,Mn)(As,C) diluted magnetic semiconductors with high C acceptor density that combines insights from phenomenological model and microscopic approaches. A tight-binding coherent potential approximation is…
Metalorganic chemical vapor deposition (MOCVD) of GaN layers doped with Mg atoms to the recognized optimum level of [Mg] $\sim2 \times 10^{19}$ cm$^{-3}$ has been performed. In a sequence of MOCVD runs, operational conditions, including…
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…
GeO$_2$ has an $\alpha$-quartz-type crystal structure with a very wide fundamental band gap of 6.6 eV and is a good insulator. Here we find that the stable rutile-GeO$_2$ polymorph with a 4.6 eV band gap has a surprisingly low $\sim$6.8 eV…
(La and Ga)-doped tin monoxide (stannous oxide, tin (II) oxide, SnO) thin films were grown by plasma-assisted and suboxide molecular beam epitaxy with dopant concentrations ranging from $\approx5\times10^{18}$cm$^{-3}$ to…
Mg is currently the only p-type dopant in technological use in GaN. Its incorporation into the GaN lattice is difficult. It requires a thermal treatment that only partially activates the Mg. To achieve moderate p-type doping requires high…
Efficient doping of semiconductor nanowires remains a major challenge towards the commercialization of nanowire-based devices. In this work we investigate the growth regimes and electrical properties of MBE-grown p- and n-type gallium…
The effect of doping of cubic boron nitride with beryllium, silicon, sulfur and magnesium on the lattice parameters, electrical conductivity and EPR spectra has been studied. It is established that the degree of doping increases…
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…
The recent discovery of high thermoelectric performance in Mg$_3$Sb$_2$ has been critically enabled by the success in $n$-type doping of this material, which is achieved under Mg-rich growth conditions, typically with chalcogens (Se, Te) as…
The sodium cobaltate system Na$_{x}$CoO$_2$ is a prominent representant of strongly correlated materials with promising thermoelectric response. In a combined theoretical and experimental study we show that by doping the Co site of the…
The recent discovery of n-type Mg$_3$Sb$_2$ thermoelectric has ignited intensive research activities on searching for potential n-type dopants for this material. Using first-principles defect calculations, here we conduct a systematic…
Using the pseudopotential density functional method, we find that a Be atom on a nanostructure with H2 molecules forms a Be-dihydrogen complex through the hybridization of the Be s or p orbits with the H2 sigma orbits and the binding energy…