
44-21Photojunction Sensors
44.7 Other Materials for Photojunction Detectors
44.7.1 Novel Materials for Photodiodes
Applications involving the detection of infrared (IR) light require the use of detector materials with
sm
all
ba
ndgaps,
<1 eV
,
co
mpared
to sil
icon
. Al
though
sil
icon
is by fa
r
th
e
mo
st
co
mmon
ma
terial
us
ed
fo
r
se
miconductor
ph
otodetectors,
sil
icon
ca
nnot
be us
ed
fo
r
ma
king
IR se
nsors
be
cause
th
e
lo
ng
wa
ve-
length
li
ght
is no
t
ab
sorbed
by th
e
sil
icon
. To ad
dress
ne
ar-IR
se
nsing,
II
I–V
se
miconductors
ar
e
us
ed
fo
r
ma
king
ph
otosensors
an
d
ph
otosensor
ar
rays
. Ta
ble
44.2 li
sts
ma
terials,
an
d
th
eir
pr
operties,
us
ed
fo
r
t
he
c
onstruction
o