@ARTICLE{Jahn_prb_2012,
  author = {Jahn, U. and L\"ahnemann, J. and Pf\"uller, C. and Brandt, O. and
	Breuer, S. and Jenichen, B. and Ramsteiner, M. and Geelhaar, L. and
	Riechert, H.},
  title = {Luminescence of {GaAs} nanowires consisting of wurtzite and zinc-blende
	segments},
  journal = Phys. Rev. B,
  year = {2012},
  volume = {85},
  pages = {045323},
  abstract = {GaAs nanowires (NWs) grown by molecular-beam epitaxy may contain segments
	of both the zincblende (ZB) and wurtzite (WZ) phases. Depending on
	the growth conditions, we find that optical emission of such NWs
	occurs either predominantly above or below the band gap energy of
	ZB GaAs (EgZB). This result is consistent with the assumption that
	the band gap energy of wurtzite GaAs (EgWZ) is larger than EgZB and
	that GaAs NWs with alternating ZB and WZ segments along the wire
	axis establish a type II band alignment, where electrons captured
	within the ZB segments recombine with holes of the neighboring WZ
	segments. Thus, the corresponding transition energy depends on the
	degree of confinement of the electrons, and transition energies exceeding
	EgZB are possible for very thin ZB segments. At low temperatures,
	the incorporation of carbon acceptors plays a major role in determining
	the spectral profile as these can effectively bind holes in the ZB
	segments. From cathodoluminescence measurements of single GaAs NWs
	performed at room temperature, we deduce a lower bound of 55 meV
	for the difference EgWZ−EgZB.},
  arxiv = {1201.6540},
  doi = {10.1103/PhysRevB.85.045323},
  issue = {4},
  numpages = {7},
  publisher = {American Physical Society}
}