Electronic structure of rare earth arsenide/gallium arsenide superlattices

Abstract

We present linear-muffin-tin-orbital calculations of the energy band structure and of the density of states of semimetal-conductor superlattices made of rare earth arsenide (ErAs and YbAs) and GaAs. The effect of size quantization and the possibility of a semimetal-semiconductor transition is studied by varying the number of rare earth arsenide monolayers buried in GaAs. We find that indeed a gap opens up in the band structure for the case of a single monolayer of YbAs embedded in GaAs, albeit well above the Fermi energy. The chances to induce a transition to a semiconductor are discussed.

Charge carrier relaxation processes in TbAs nanoinclusions in GaAs measured by optical-pump THz-probe transient absorption spectroscopy

“…To evaluate this possibility in ErAs nanoinclusions, linear-muffin-tin-orbital calculations have been used to compute the energy band structure and the density of states of an ErAs:GaAs superlattice. Using this approach, Said found that the presence of interface states prevents the heterostructure from transitioning from a semimetal into a semiconductor when the number of ErAs monolayers was varied [25]. Furthermore, a Maxwell-Garnett formulation and semiclassical transport theory suggest that near-infrared absorption in ErAs nanoinclusions should be attributed to a plasmon resonance rather than the opening of a band gap [26].…”

Molecular Polyarsenides of the Rare‐Earth Elements

“…[ (Cp'' 2 Sm)(m,h 4 :h 4 -As 4 )(Cp*Fe)] is also the first d/f-triple decker sandwich complex with ap urely inorganic planar middle deck. [6] Proposed applications include multijunction solar cells, [7] transparent electrical contacts, [8] and thermoelectric devices. DFT calculations confirm all the structural observations.T he AsÀAs bond order inside the cyclo As 4 ligand in [(Cp'' 2 Sm)(m,h 4 :h 4 -As 4 )(Cp*Fe)] was estimated to be in between an As À As single bond and aformally aromatic As 4 2À system.…”

“…[2] Recently,t hey have been utilized as epitaxial nanoparticles [3] and nanostructures [4] in combination with the well-established III-V semiconductor GaAs. [6] Proposed applications include multijunction solar cells, [7] transparent electrical contacts, [8] and thermoelectric devices. [6] Proposed applications include multijunction solar cells, [7] transparent electrical contacts, [8] and thermoelectric devices.…”

“…[2a,5] Rare-earth arsenides can also be epitaxially grown as single crystals on III-V substrates. [6] Proposed applications include multijunction solar cells, [7] transparent electrical contacts, [8] and thermoelectric devices. [9] Although the solidstate chemistry of rare-earth arsenides is rich, [10] the number of structurally characterized molecular rare-earth arsenides is surprisingly low.T ot he best of our knowledge,o nly six structurally characterized compounds with Ln À As bonds, namely LnÀAsR 2 [11] and LnÀAs(R)ÀLn, [12] are known.…”

Determining the band alignment of TbAs:GaAs and TbAs:In0.53Ga0.47As

“…13 Models of ErAs:GaAs superlattices show that interface states from the As atoms prevent the ErAs from transitioning from a semimetal into a semiconductor, even when the ErAs layer is reduced to one monolayer. 14 Our recent carrier dynamics study shows that TbAs nanoparticles in GaAs are saturable, in direct contrast to ErAs nanoparticles, and likely have a band gap. 15 Although TbAs nanoparticles are of interest for a variety of device applications, many details of their electronic structure in III-V semiconductors are presently unknown.…”