
43-1
43.1 Introduction
Photoconduction has been observed, studied, and applied for more than 100 years. In the year 1873,
W.
Smith
[1
]
no
ticed
th
at
th
e
re
sistance
of a se
lenium
re
sistor
de
pended
on il
lumination
by li
ght
. Si
nce
th
at
ti
me,
ph
otoconduction
ha
s
be
en
an im
portant
too
l
us
ed
to ev
aluate
ma
terial
pr
operties,
to st
udy
se
miconductor
de
vice
ch
aracteristics,
an
d
to co
nvert
opt
ical
in
to
el
ectric
sig
nals
. e Ra
dio
Co
rporation
of Am
erica
(R
CA)
wa
s
a le
ader
in th
e
st
udy
an
d
de
velopment
of ph
otoconductivity
an
d
of ph
otoconduc-
tive
de
vices
. Ri
chard
H. Bu
be
of RC
A
La
boratories
wr
ote
th
e
cl
assic
bo
ok
Ph
otoconductivity in Solids
[2] in 1960. Tod ...