Dop
in
g T
iO
2 w
ith n
itro
gen
is reco
gn
ized as a procedure to
get sens
it
izat
ion of th
is mater
ial w
ith v
is
ible l
ight.In the present work,
incorporat
ion of n
itro
gen w
ith
in the structure of T
iO
2 th
in f
ilms has been accompl
ishedby N
2+ ion
implantat
ion
in T
iO
2 anatase th
in f
ilms (50 keV
ion ener
gy for doses of 3 × 10
16, 6 × 10
16, and1.2 × 10
17 ions cm
-2) and dur
in
g preparat
ion by metalor
gan
ic chem
ical vapor depos
it
ion (MOCVD) us
in
gn
itro
gen as carr
ier
gas. The analys
is of the samples by X-ray photoem
iss
ion spectroscopy (XPS) and for theMOCVD samples also by secondary
ion mass spectroscopy (SIMS) has shown that n
itro
gen,
in the form ofn
itr
ide-l
ike spec
ies, (N/T
i rat
ios of 0.03 and 0.12 for the MOCVD and the
implanted samples, respect
ively)has become effect
ively
incorporated w
ith
in the structure of T
iO
2. The water contact an
gle on the
implantedth
in f
ilms var
ied from about 80
ima
ges/ent
it
ies/de
g.
gif"> to around 30
ima
ges/ent
it
ies/de
g.
gif"> when
illum
inated w
ith v
is
ible l
ight, depend
in
g on the
iondose. S
im
ilarly, the MOCVD samples showed a sharp decrease
in wett
in
g contact an
gle under v
is
ible l
ightfrom about 80
ima
ges/ent
it
ies/de
g.
gif"> to 55
ima
ges/ent
it
ies/de
g.
gif">. In the two cases, the th
in f
ilms reach total hydroph
il
ic
ity by poster
ior UV
irrad
iat
ion.To account for these results, the poss
ible ex
istence of spec
if
ic exc
itat
ion mechan
isms for v
is
ible or UV photons,the former
involv
in
g the
incorporated n
itro
gen atoms,
is d
iscussed.