SIZE CONTROL OF SELF-ASSEMBLED QUANTUM WIRES FOR EMISSION WAVELENGTH
ENGINEERING, L. González1, Y. González1, D. Granados1, J. M. García1,
D. Fuster2 and J.Martínez-Pastor2, 1Instituto de Microelectrónica de
Madrid (CNM-CSIC), C/ Isaac Newton 8 (PTM), 28760-Tres Cantos
(Madrid). Spain, 2Instituto de Ciencia de los Materiales, Universidad
de Valencia, P.O. Box 2085, 46071 Valencia, Spain.
It is now well established that nanowires formation along [1[
[image002.gif] ]0] takes place when an InAs thin layer (about 2.7
monolayers, ML) is grown by MBE on InP (001) substrate. Strain
relaxation is the driving force for the unidirectional observed
surface roughening due to the asymmetric accumulated stress during MBE
growth of a lattice-mismatch III-V/III-V' heteroepitaxial system.
InAs/InP(001) nanowires produce photoluminiscence (PL) emission at l ť
1.5 mm at room temperature. However it should be desirable to exactly
tune the emission wavelength to the optimum for communication devices
(l = 1.55 mm) as well as to any other wavelength under design.
One possible way is to actuate on carrier confinement by using ternary
alloys to change both lattice-mismatch (to change the nanowire size)
and composition (to change the nanowire band gap).
In this work we have grown by MBE samples consisting of In[1-x]Ga[x]As
and In[1-x]Al[x]As (0<x<0.85), with different thickness, on InP (001).
Measurements of surface topography made by atomic force microscopy
show period of the wires from 17 nm to 45 nm for lattice-mismatch from
3.2% to 2.2%. Results on PL emission wavelength range obtained in
similar samples but adding an InP capping layer will be shown.