0000000000736160
AUTHOR
Luis C. O. Dacal
An ab initio study of the polytypism in InP
AbstractThe existence of polytypism in semiconductor nanostructures gives rise to the appearance of stacking faults which many times can be treated as quantum wells. In some cases, despite of a careful growth, the polytypism can be hardly avoided. In this work, we perform an ab initio study of zincblende stacking faults in a wurtzite InP system, using the supercell approach and taking the limit of low density of narrow stacking faults regions. Our results confirm the type II band alignment between the phases, producing a reliable qualitative description of the band gap evolution along the growth axis. These results show an spacial asymmetry in the zincblende quantum wells, that is expected …
Valence-band splitting energies in wurtzite InP nanowires : Photoluminescence spectroscopy and ab initio calculations
We investigated experimentally and theoretically the valence-band structure of wurtzite InP nanowires. The wurtzite phase, which usually is not stable for III-V phosphide compounds, has been observed in InP nanowires. We present results on the electronic properties of these nanowires using the photoluminescence excitation technique. Spectra from an ensemble of nanowires show three clear absorption edges separated by 44 meV and 143 meV, respectively. The band edges are attributed to excitonic absorptions involving three distinct valence-bands labeled: A, B, and C. Theoretical results based on “ab initio” calculation gives corresponding valence-band energy separations of 50 meV and 200 meV, r…
Erratum: Polarized and resonant Raman spectroscopy on single InAs nanowires (vol 84, 085318, 2011)
We found out that the polar pattern for the zinc-blende InAs LO mode displayed in Fig. 2(b) of our original paper represents the backscattering Raman intensities from a (11¯2) top surface and not as stated in the original manuscript from a (110) top surface.In the latter the LO mode is forbidden for all configurations.
Ab initio electronic band structure calculation of InP in the wurtzite phase
Abstract We present ab initio calculations of the InP band structure in the wurtzite phase and compare it with that of the zincblende phase. In both calculations, we use the full potential linearized augmented plane wave method as implemented in the WIEN2k code and the modified Becke-Johnson exchange potential, which provides an improved value of the bandgap. The structural optimization of the wurtizte InP gives a = 0.4150 nm , c = 0.6912 nm , and an internal parameter u = 0.371 , showing the existence of a spontaneous polarization along the growth axis. As compared to the ideal wurtzite structure (that with the lattice parameter derived from the zincblende structure calculations), the actu…
Ab initio calculations of indium arsenide in the wurtzite phase: structural, electronic and optical properties
Most III-V semiconductors, which acquire the zinc-blende phase as bulk materials, adopt the metastable wurtzite phase when grown in the form of nanowires. These are new semiconductors with new optical properties, in particular, a different electronic band gap when compared with that grown in the zinc-blende phase. The electronic gap of wurtzite InAs at the Gamma-point of the Brillouin zone (E0 gap) has been recently measured, E0 = 0.46 eV at low temperature. The electronic gap at the A point of the Brillouin zone (equivalent to the L point in the zinc-blende structure, E1) has also been obtained recently based on a resonant Raman scattering experiment. In this work, we calculate the band st…
Polarized and resonant Raman spectroscopy on single InAs nanowires
We report polarized Raman scattering and resonant Raman scattering studies on single InAs nanowires. Polarized Raman experiments show that the highest scattering intensity is obtained when both the incident and analyzed light polarizations are perpendicular to the nanowire axis. InAs wurtzite optical modes are observed. The obtained wurtzite modes are consistent with the selection rules and also with the results of calculations using an extended rigid-ion model. Additional resonant Raman scattering experiments reveal a redshifted E1 transition for InAs nanowires compared to the bulk zinc-blende InAs transition due to the dominance of the wurtzite phase in the nanowires. Ab initio calculatio…