Band alignment tailoring of InAs1-xSbx/GaAs quantum dots: control of type I to type II transition.
We report the growth of InAs(1-x)Sb(x) self-assembled quantum dots (QDs) on GaAs (100) by molecular beam epitaxy. The optical properties of the QDs are investigated by photoluminescence (PL) and time-resolved photoluminescence (TRPL). A type I to type II band alignment transition is demonstrated by both power-dependent PL and TRPL in InAs(1-x)Sb(x) QD samples with increased Sb beam flux. Results are compared to an eight-band strain-dependent k x p model incorporating detailed QD structure and alloy composition. The calculations show that the conduction band offset of InAs(1-x)Sb(x)/GaAs can be continuously tuned from 0 to 500 meV and a flat conduction band alignment exists when 60% Sb is incorporated into the QDs. Our study offers the possibility of tailoring the band structure of GaAs based InAsSb QDs and opens up new means for device applications.
He
J
J
California NanoSystems Institute, University of California, Los Angeles, California 90095, USA. hejun@ee.ucla.edu
Reyner
C J
CJ
Liang
B L
BL
Nunna
K
K
Huffaker
D L
DL
Pavarelli
N
N
Gradkowski
K
K
Ochalski
T J
TJ
Huyet
G
G
Dorogan
V G
VG
Mazur
Yu I
YI
Salamo
G J
GJ