Chemistry Reference
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(a)
Top (planarizing)
GaAs layer
s.l.
bottom
GaAs
substrate
100 nm
(b)
30 nm
InP dots
GalnP
GaAs substrate
Figure 5.3
(a) TEM micrograph of a quantum wire structure, achieved by growing
a multilayer structure in a V-shaped groove. Variation of alloy growth rate
on the side walls and base of the groove lead to the formation of quantum
wires at the bottom of the groove, in which carriers are free only to move
along the direction of the groove (from Biasiol and Kapon, © 1998 by the
American Physical Society). (b) TEM of a quantum dot structure: when,
for example, InP is grown on GaInP under appropriate growth conditions,
the lattice-mismatch between the InP and GaInP leads to the formation of
'self-ordered' InP islands in the GaInP matrix (from Eberl 1997).
where
is the band edge
potential distribution, given in the quantum well case of fig. 5.2 by
V
ψ(
z
)
is the electron envelope function and
V
(
z
)
(
z
)
=
E
c
. To calculate the electron (and hole) states in such a square well, we
require at the interface between the well, W, and barrier, B, layers that
(
z
)
ψ
=
ψ
(5.2a)
W
B
