We report measurements of hot-carrier photoluminescence from GaAs V-gr
oove quantum wires. cw spectra reveal distinct one-dimensional subband
s: at low excitation density recombination from laterally confined n(y
) = 1 states is dominant, which shows that carriers relax efficiently
to the lowest subband; n(y) = 2 and 3 recombination becomes pronounced
at higher temperature and density, which indicates inhibited relaxati
on, possibly due to band filling. Time-resolved photoluminescence meas
urements at 10 K show a rise time of approximately 100 ps, which is du
e to energy relaxation. At later times the intensity of the n(y) = 1 l
ine shows a monotonic decay at low carrier density, but there is a pro
nounced plateau at high density that extends for approximately 200 ps.
These results provide clear evidence of carrier relaxation and band f
illing in quantum wires.