43-6 Optical
43.3.2 Lead Sulde
PbS was among the earliest IR detector material investigated. Cashman was one of the earliest research-
ers
in th
e
Un
ited
Sta
tes
. [1
2]
. i
s
in
trinsic
de
tector
ma
terial
is pr
epared
by de
position
of po
lycrystalline
th
in
l
ms
by va
cuum
su
blimation
or ch
emical
de
position
fr
om
a so
lution
. e sp
ectral
re
sponse
ex
tends
to ap
proximately
3 μm. Pb
S
op
erates
ov
er
th
e
te
mperature
ra
nge
fr
om
77 K to ro
om
te
mperature
. e
fr
equency
re
sponse
sl
ows
co
nsiderably
at th
e
lo
west
te
mperatures
. e sp
ectral
re
sponse
ex
tends
to
somewhat longer wavelengths with cooling.
43.3.3 Lead Selenide
PbSe is an intrinsic detector that operates over the temperature range from 77 K to room temperature.
It
s
sp
ectral
re
sponse
ex
tends
to lo
nger
wa
veleng ...