We present structural characterization of the wurtzite crystal structure of GaP nanowires, which were recently shown to have a direct electronic band gap. The structural parameters of the wurtzite phase do consist of two lattice parameters and one internal degree of freedom, determining the Ga-P bond length along the c direction. Using density functional theory calculations, we study the influence of the internal degree of freedom on the band structure. By synchrotron x-ray diffraction studies near the Ga-K edge we determine the lattice parameters a=3.8419 Å and c=6.3353 Å as well as the internal degree of freedom u=0.37385 with high accuracy. We find that different Ga-P bond lengths are not equal, in contrast to the case in the zinc blende bulk phase. As a result, a spontaneous polarization is predicted for wurtzite GaP.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Sep 30 2013|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics