Localization-dependent photoluminescence spectrum of biexcitons in semiconductor quantum wires.
We study exciton and biexciton spectra in disordered semiconductor quantum wires by means of nanophotoluminescence spectroscopy. We demonstrate a close link between the exciton localization length along the wire and the occurrence of a biexciton spectral line. The biexciton signature appears only if the corresponding exciton state extends over more than a few tens of nanometers. We also measure a nonmonotonous variation of the biexciton binding energy with decreasing exciton localization length. This behavior is quantitatively well reproduced by the solution of the single-band Schrödinger equation of the four-particle problem in a one-dimensional confining potential.
Feltrin
A
A
Institut de Photonique et d'Electronique Quantiques, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
Michelini
F
F
Staehli
J L
JL
Deveaud
B
B
Savona
V
V
Toquant
J
J
Wang
X L
XL
Ogura
M
M