ᨺᑕගࢆ⏝࠸ࡓゐ፹άᛶᵓ㐀ࡢ᫬㛫ศゎゎᯒศᏊ⛉Ꮫ◊✲ᡤ ၏ ⨾ὠᮌ⌧௦♫఍࡛ỗ⏝ࡉࢀࡿከ✀ከᵝ࡞᭷⏝໬ྜ≀ࡢṤ࡝ࡀࠊᅛయゐ፹ࡢᏑᅾୗࠊேᕤⓗ࡟኱㔞ྜᡂࡉࢀ࡚࠾ࡾࠊ㧗άᛶ࣭㧗㑅ᢥᛶࢆᢸ࠺ᅛయゐ፹⾲㠃ࡢྜ⌮ⓗタィࡣࠊḟୡ௦ࡢ໬Ꮫᢏ⾡ࢆᨭ࠼ࡿ㔜せㄢ㢟ࡢࡦ࡜ࡘ࡛࠶ࡿࠋࡇࡢࡓࡵ࡟ࡣࠊᅛయ⾲㠃ୖ࡛㧗άᛶ࣭㧗㑅ᢥᛶࢆᢸ࠺ゐ፹άᛶᵓ㐀ࢆศᏊ࡛ࣞ࣋ࣝᆒ㉁࡟సᡂࡍࡿゐ፹⾲㠃ࡢタィᡭἲࢆᣢࡕࠊࡲࡓゐ፹཯ᛂࡀຠ⋡Ⰻࡃ㐍⾜ࡋ࡚࠸ࡿࡑࡢሙ (in-situ) ࡛ࠊ࠿ࡘ≀㉁ኚ᥮ࡀᡂࡉࢀࡿ᫬㛫ࢫࢣ࣮࡛ࣝࠊ⾲㠃ࡢゐ፹άᛶᵓ㐀ࡀ࡝ࡢࡼ࠺࡟ാࡃ࠿ࠊࡑࡢࢲ࢖ࢼ࣑ࢵࢡ࡞ᵓ㐀ኚ໬ࢆ⌮ゎࡍࡿࡇ࡜ࡀᚲせ࡛࠶ࡿࠋᡃࠎࡣࠊ⊂⮬ࡢゐ፹⾲㠃ࡢศᏊࣞ࣋ࣝタィἲ࡟ࡼࡾࠊᅛయ⾲㠃ୖ࡟ᆒ㉁࡞㧗άᛶゐ፹ᵓ㐀ࢆసࡾศࡅࠊᨺᑕග࠿ࡽฟࡿ◳ X ⥺ࢆ฼⏝ࡋࡓ in-situ ᫬㛫ศゎ XAFS ᵓ㐀ゎᯒ࡟ྲྀࡾ⤌ࢇ࡛ࡁࡓࠋ࢚ࢿࣝࢠ࣮ศᩓᆺ DXAFS ࡸ QXAFS ἲࡢ᫬㛫ศゎ XAFS ἲࢆ㥑౑ࡍࡿࡇ࡜࡟ࡼࡾࠊ
୍㐣ᛶࡢ༢Ⓨ཯ᛂ㐣⛬࡟࠾࠸࡚ࠊ᫬ࠎ้ࠎኚ໬ࡍࡿゐ፹⮬㌟ࡢືࡁࡸാࡁࢆࣜ࢔ࣝࢱ࢖࣒࡛
᫂ࡽ࠿࡟ࡍࡿࡇ࡜࡟ᡂຌࡋࠊ≀㉁ኚ᥮࡟࠾ࡅࡿゐ፹⮬㌟ࡢᵓ㐀㏿ᗘㄽࢆᥦ᱌ࡋࡓࠋ㧗άᛶࢆᢸ࠺ゐ፹ࡢᮏ㉁ࢆ᫂ࡽ࠿࡟ࡋࠊྠ᫬࡟ゐ፹⮬㌟ࡢᵓ㐀ࢆタィ࡛ࡁࡿᡭἲࢆᣢࡘࡇ࡜࡛ࠊึࡵ
࡚ḟࡢゐ፹タィ࡟㏻ࡌࡿᵓ㐀ゎᯒࡀᐇ⌧࡛ࡁࡿࠋࡇࡇ࡛ࡣࠊin-situ ᫬㛫ศゎ XAFS ࡟ࡼࡿᐇ㧗άᛶゐ፹࡟࠾ࡅࡿゐ፹཯ᛂ㐣⛬ࡢࣜ࢔ࣝࢱ࢖
࣒ᵓ㐀ゎᯒ࡜ࡋ࡚ࠊ(1) ክࡢゐ፹཯ᛂ㸫࣋ࣥࢮࣥ࡜㓟⣲࠿ࡽࡢࣇ࢙ࣀ୍࣮ࣝẁྜᡂ࡟ୡ⏺᭱㧗ࡢゐ፹≉ᛶࢆ♧ࡍ᪂ᆺ Re ゐ፹ࡢࢲ࢖ࢼ࣑ࢵࢡᵓ㐀ኚ໬ࡢゎᯒ[1]ࠊ(2) ᐇ⇞ᩱ㟁ụ Pt/C ࢝ࢯ࣮ࢻゐ፹㐠㌿᫬ࡢ⾲㠃཯ᛂ࡜ゐ፹ຎ໬ᶵᵓࡢゎ᫂[2]ࠊ(3) ⮬ື㌴᤼࢞ࢫί໬ CZ ゐ፹࡟࠾ࡅࡿ㓟⣲྾ⶶ/ᨺฟ㐣⛬ࡢゎᯒࢆ⤂௓ࡍࡿ[3]ࠋ

[1] R. Bal, M. Tada, T. Sasaki, Y. Iwasawa, Angew. Chem. Int. Ed. 45, 448-452 (2006). [Hot paper][2] M. Tada, S. Murata, T. Asaoka, K. Hiroshima, K. Okumura, H. Tanida, T. Uruga, H. Nakanishi, S.
Matsumoto, Y. Inada, M. Nomura, Y. Iwasawa, Angew. Chem. Int. Ed. 46, 4310-4315 (2007).
[3] T. Yamamoto, A. Suzuki, Y. Nagai, T. Tanabe, F. Dong, Y. Inada, M. Nomura, M. Tada, Y.
Iwasawa, Angew. Chem. Int. Ed. 46, 9253-9256 (2007).

㸫㸫

ㆬᛯ⸅ᇦ෻ᔕ೙ᓮ䉕ᗧ࿑䈚䈢ಽሶ䊧䊔䊦⸅ᇦ⴫㕙⸳⸘᡼኿శ䉕↪䈇䈢⸅ᇦᵴᕈ᭴ㅧ䈱ᤨ㑆ಽ⸃⸃ᨆ
ಽሶ⑼ቇ⎇ⓥᚲ᡼኿శᄞ䈱෻ᔕ䊔䊮䉷䊮䈎䉌䈱ᄞ䈱෻ᔕ䊔䊮䉷䊮䈎䉌䈱䊐䉢䊉䊷䊦⋥ធวᚑ䈮䊐䉢䊉䊷䊦⋥ធวᚑ䈮਎⇇ᦨ㜞䈱⸅ᇦᕈ⢻䉕਎⇇ᦨ㜞䈱⸅ᇦᕈ⢻䉕␜䈜ᣂဳ⸅ᇦ䉕㐿⊒␜䈜ᣂဳ⸅ᇦ䉕㐿⊒

1 s㑆䈮1600࿁, 38,800,000࿁䈱⸅ᇦ䉰䉟䉪䊦䉕ታ⃻໑ ⟤ᵤᧁ㛳⇣⊛䈭⸅ᇦᵴᕈ䉕ታ⃻㛳⇣⊛䈭⸅ᇦᵴᕈ䉕ታ⃻

⊒㔚

e-

L2
㔚⸃⾰

L3

H2O

eH+
H+

H2

6

O2

4

12

2

H+

8

0
0

1

Angew. Chem. Int. Ed. 45, 448 (2006).
J. Phys. Chem. C 111, 10095 (2007).

3

time / s4

ClO4 - ClO4 -㍲૕䉕⴫㕙䈮䈱䈞䉎㍲૕䉕⴫㕙䈮䈱䈞䉎䈣䈔䈪ਇᢧ䈏⊒⃻䈣䈔䈪ਇᢧ䈏⊒⃻

0

5

N
O

-

HO
-

HO
-

-

-

OH
-

-

OH

HO

-

OH

-

-

OH

OH

OH

-

HO

HO HO

H

OH OH
OH

OH

+

OH
-

OH
HO OH O
OH
O
O
HO
OH
O OHO OH
O OH
OH O
O
O
O
OH OH
HO HO
O
OH
OHO
O
O O O

-OH

OH

HO HO O OH O
OH
OH
OH
OO
O HO HO OH OH OH
OH
O
O

OH

-

-

OH

O

OH

OH

Cu

t-Bu

O
-

㪊ᰴర⚦ሹ䈻䈱࿕ቯൻ䍃᭴ㅧᄌ឵Chem. Commun., 2562 (2004).
Chem. Commun., 2506 (2005).
Angew. Chem. Int. Ed. 46, 7220 (2007).
Angew. Chem. Int. Ed. 47, 9230 (2008).
Angew. Chem. Int. Ed. 47, 9252 (2008).

4
2

R /10 -1 nm

H
OH H
OH
H H
H
HO OH
OH
H
H
H
HO HO
OH H
OH
H
OH
H OH
H
H HOH
OH
HO
OH
H
H
HO
OH
H

L1

M

㊄ዻ㍲૕䈱⴫㕙࿕ቯൻ䊶ቅ┙ൻ

|FT|[k 3 F(k)]

t-Bu

N

O

O

O

O
O O

O

HN O
ਇᢧ䈪䈭䈇ಽሶ䉕૶䈦䈩OSi OMeO NH
ਇᢧ䈪䈭䈇ಽሶ䉕૶䈦䈩
O
OO
O Si
MeO O
O
Si
O
⴫㕙਄䈪ਇᢧჇ᏷
⴫㕙਄䈪ਇᢧჇ᏷
EtO O
O Si

Si OEtMeO Si O O
SiOOOO OMe⴫㕙ਇᢧ⥄Ꮖ⚵❱ൻChem. Commun., 2542 (2004).
J. Phys. Chem. B 109, 9905 (2005).

ታΆᢱ㔚ᳰ䈱Pt䉦䉸䊷䊄⸅ᇦ䈱ഠൻᯏ᭴䉕਎⇇䈪ೋ䉄䈩⸃᣿OO

ੱᎿ㉂⚛⸅ᇦ䉕⥄࿷䈮⴫㕙䈮⸳⸘ੱᎿ㉂⚛⸅ᇦ䉕⥄࿷䈮⴫㕙䈮⸳⸘

OMe⴫㕙䊝䊧䉨䊠䊤䊷䉟䊮䊒䊥䊮䊁䉞䊮䉫
Phys. Chem. Chem. Phys. 4, 4561 (2002).
Phys. Chem. Chem. Phys. 4, 5899 (2002).
J. Catal. 211, 496 (2002).
J. Phys. Chem. B 108, 2918 (2004).

⴫㕙ⓨ㑆ൻቇୃ㘼Chem. Lett. 34, 1362 (2005).
J. Catal. 245, 173 (2007).

M.
M. TadaTada andand Y.
Y. Iwasawa,Iwasawa, Chem.
Chem. Commun.
Commun. (Invited(Invited Feature
Feature Article),
Article), 2833
2833 (2006).
(2006).

XAFS X-ray Absorption Fine Structure(XAFS) Spectrum䊐䉢䊉䊷䊦⋥ធวᚑ↪䈱ᣂဳRe⸅ᇦ䈱ഃ಴䊐䉢䊉䊷䊦⋥ធวᚑ↪䈱ᣂဳRe⸅ᇦ䈱ഃ಴䊐䉢䊉䊷䊦 䋭 Ფᐕ100䊜䉧䊃䊮એ਄䈏䊔䊮䉷䊮䈎䉌วᚑPF

ㆊ෰40ᐕ䈱㑆䇮5%એ਄䈱䊔䊮䉷䊮ォൻ₸䇮䈎䈧
50%એ਄䈱䊐䉢䊉䊷䊦ㆬᛯᕈ䉕␜䈜⸅ᇦ䈲䈭䈇䇯

O

NH 3

CVD

Re
CH 3 HZSM-5

⸅ᇦᵴᕈ⒳

O
O
Re
O
Re
Re
Re
N Re OO Re N Re
Re
Re
O
Re
O
O O
Al
HZSM-5O2OO

F( k ) = 6 A j ( k ) sin( 2 k Rj + Iij ( k ) )jA j ( k ) = N j S j ( k ) F j ( k) e xp ( - 2 Vj 2 k 2 ) e xp ( - 2 R j / O( k ) ) / k Rj 2

XANES

Re

EXAFS
(1) Interatomic distance(2) Coordination number(3) Debye Waller factor
400 eV

20 eV

I

P

᷹ቯ⹜ᢱ
䊑䊤䉾䉫ⷺ
Bragg㈩⟎Photoelectron backscatteringfrom local environmentᤨ㑆ಽ⸃XAFSᴺ䈮䉋䉎⸅ᇦ⥄り䈱᭴ㅧㅦᐲ⺰⸃᣿⸅ᇦ䊅䊉☸ሶ䈱፣უ䊶ಽᢔㆊ⒟䉕⋥ធ᷹ⷰ⸅ᇦ䊅䊉☸ሶ䈱፣უ䊶ಽᢔㆊ⒟䉕⋥ធ᷹ⷰ

Dispersive XAFS (DXAFS)

䌘✢

X-ray

Photon energy

Core electron transition
to unoccupied valence orbitals

Quick XAFS (QXAFS)

2 m ( E- Eo e xp ) / h 2k =O
HZSM-5ᤨ㑆ಽ⸃XAFS᷹ቯᴺᤨ㑆ಽ⸃XAFS᷹ቯᴺ
I0

2

250 eV

Angew.
Angew. Chem.
Chem. Int.
Int. Ed.
Ed. 45,45, 448448 (2006)(2006) (HOT(HOT PAPERㆬቯ)
PAPERㆬቯ)ᦺᣣᣂ⡞ઁ6⹹䈮ឝタ.
ᦺᣣᣂ⡞ઁ6⹹䈮ឝタ.

䊝䊉䉪䊨䊜䊷䉺䊷

Bragg angle

EXAFS(1) Oxidation state(2) Coordination(3) SymmetryOsample'P F

OO⓸⚛ౝ൮ᣂဳRe10䉪䊤䉴䉺䊷

X-ray

PF

CH3ReO3䈱
CVD 䈮䉋䉎
⚦ሹౝ࿕ቯൻ

Ꮏᬺ⊛ታ⃻䈱ო䉕ೋ䉄䈩Ꮏᬺ⊛ታ⃻䈱ო䉕ೋ䉄䈩⿥䈋䉎ᣂဳ⸅ᇦ䉕ႎ๔䇯⿥䈋䉎ᣂဳ⸅ᇦ䉕ႎ๔䇯ォൻ₸10%,
ㆬᛯᕈ94%䉕ォൻ₸10%,
ㆬᛯᕈ94%䉕HO਎⇇䈪ೋ䉄䈩ታ⃻䇯਎⇇䈪ೋ䉄䈩ታ⃻䇯I

I0

Crystal

XANES< 50eV䉪䊜䊮ᴺ: ῜⊒ᕈㆊ㉄ൻ‛䊶Ớ⎫㉄䉕૶䈉3Ბ㓏䊒䊨䉶䉴䇯ᄞ䈱෻ᔕ: 䊔䊮䉷䊮䈫O2䈎䉌1Ბ䈪䊐䉢䊉䊷䊦䉕วᚑ (C&ENews)㪦㪉䊘䊥䉪䊨䊜䊷䉺䊷

R

Angew. Chem. Int. Ed. 42, 4795 (2003).

q

䉰䊮䊒䊦

Angew. Chem. Int. Ed. 45, 448 (2006).
J. Phys. Chem. C 111, 10095 (2007).

䊐䉢䊉䊷䊦⋥ធวᚑ䈱⸅ᇦᵴᕈ᭴ㅧ䈱௛䈐䉕⸃᣿䊐䉢䊉䊷䊦⋥ធวᚑ䈱⸅ᇦᵴᕈ᭴ㅧ䈱௛䈐䉕⸃᣿|FT|[k 3 F(k)](1) ᬦ౞ḧᦛ⚿᥏䈪ಽశ(2) ⹜ᢱ䈲᷹ቯኻ⽎䈱䉣䊈䊦䉩䊷䉕৻᜼䈮ๆ෼(1) 䊝䊉䉪䊨䊜䊷䉺䊷䉕㜞ㅦ䈪᝹ᒁ(2) Ꮧ⭯⹜ᢱ䈻䈱ㆡᔕ䈏น⢻

64⥄േゞឃ䉧䉴⸅ᇦ䈱⥄േゞឃ䉧䉴⸅ᇦ䈱㉄⚛ๆ⬿㉄⚛ๆ⬿//᡼಴ㆊ⒟䈮
᡼಴ㆊ⒟䈮
䈍䈔䉎ᣂ⃻⽎䉕⊒⷗䈍䈔䉎ᣂ⃻⽎䉕⊒⷗

Pt

Energy / eV

Energy / eV৻ㆊᕈ෻ᔕ䈱䊥䉝䊦䉺䉟䊛᷹ቯ:৻ㆊᕈ෻ᔕ䈱䊥䉝䊦䉺䉟䊛᷹ቯ:

1 spectrum (EXAFS) : 50 ms 䌾

1 spectrum: 10 㱘s 䌾 (100 ms)ታΆᢱ㔚ᳰ⸅ᇦ䈱ታΆᢱ㔚ᳰ⸅ᇦ䈱⿠㔚ᤨ䈱⴫㕙෻ᔕ䈫⿠㔚ᤨ䈱⴫㕙෻ᔕ䈫ഠൻᯏ᭴䉕⸃᣿
ഠൻᯏ᭴䉕⸃᣿

H
OH H
OH
H H
H
HO OH
OH
H
H
H
HO HO
OH H
OH
H
OH
H OH
H
H H OH
OH
HO
H
OH
H
HO
OH
H

8

0
0

OH OH

-

-

-

HO HO

OH

-

-

-

OH

OH

OH

OH

OH

-

OH
-

OH

-

-

OH

2

-OH

H+

- -

HO OH
-

HO HO-

1

4

R /10 -1 nm

Angew. Chem. Int. Ed. 46, 9253 (2007).

Pt

12

2

-

3

time / s
4

OH

OH

-OH
HO OH
O
OH
HO O OH OH
OH
OO
O OH
HO HO- OH OH
OH
O
O

HO

0

5

OH

HO OH OOHOOOHO OHO OH
O OH
OH O
O
O
O
OH
OH
HO HO
O
OH
OHO
O
O
O O

HO

Angew. Chem. Int. Ed. 46, 4310 (2007).

㸫㸫

In-situᤨಽഀXAFS䈮䉋䉎Άᢱ㔚ᳰ⸅ᇦ䈱䊥䉝䊦䉺䉟䊛᭴ㅧ⸃ᨆ- Άᢱ㔚ᳰゞታ⃻䈻ะ䈔䈢⺖㗴⸃᳿䈮䈧䈭䈏䉎䈎䋿 -⊒㔚᧦ઙਅ䈪䈱Άᢱ㔚ᳰ⸅ᇦ䈱in-situ XAFS᷹ቯ⎬X✢䈱㜞䈇ㅘㆊജ䉕↪䈇䇮ᄢ㊂䈱᳓䈏ሽ࿷䈜䉎⊒㔚᧦ઙਅ䈪䉅䇮Pt䊅䊉☸ሶ⸅ᇦ䈱in-situ᭴ㅧⷰኤ䉕ታ⃻䈚䈢䇯
PC(QXAFS)⊒㔚e-

Trigger

PC(P/G stat)㔚⸃⾰㔚᳇ൻቇ⸘᷹䈫㔚᳇ൻቇ⸘᷹䈫XAFS
XAFS᷹ቯ䉕᷹ቯ䉕หᤨ䈮ⴕ䈇䇮Άᢱ㔚ᳰ䈏௛䈇䈩䈇䉎หᤨ䈮ⴕ䈇䇮Άᢱ㔚ᳰ䈏௛䈇䈩䈇䉎䈠䈱႐䈪⸅ᇦ䈱᭴ㅧᄌൻ䉕ᝒ䈋䈢䇯䈠䈱႐䈪⸅ᇦ䈱᭴ㅧᄌൻ䉕ᝒ䈋䈢䇯Counter

eH+

O2

H2

P/G stat

Encorder
H+

ࠕࡁ࡯࠼
⸅ᇦ

H2O

Angew.
Angew. Chem.
Chem. Int.
Int. Ed.
Ed. 46,46, 4310
4310 (2007).
(2007).

ࠞ࠰࡯࠼⸅ᇦ

2007ᐕ3᦬
2007ᐕ3᦬ ᣣ⚻↥ᬺᣂ⡞ઁ5⹹䈮ឝタ.
ᣣ⚻↥ᬺᣂ⡞ઁ5⹹䈮ឝタ.
2007ᐕ3᦬
2007ᐕ3᦬ ╙99࿁⸅ᇦ⸛⺰ળᵈ⋡⊒⴫.
╙99࿁⸅ᇦ⸛⺰ળᵈ⋡⊒⴫.
2008ᐕ᧲ᶏൻቇᎿᬺળᛛⴚ⾨.
2008ᐕ᧲ᶏൻቇᎿᬺળᛛⴚ⾨.

V-F
converter

Current ampliferSi(111)
monochromatorcathodemirror2

Synchrotron

X-rayΆᢱ㔚ᳰゞታ⃻䈱䈢䉄䈱ᔅ㗇⺖㗴
mirror1- ゞ૕䈱ᷫㅦ: 㔚ᳰ♽䈱On/Off (㔚࿶೙ᓮ) 䉕ⶄᢙ࿁➅䉍㄰䈜䈖䈫䈏ᔅⷐ- 䈖䈱On/Offᠲ૞䉕➅䉍㄰䈜䈫䇮ᓢ䇱䈮䉦䉸䊷䊄䈱Pt⸅ᇦ䈏㔚⸃⾰ጀ䈮ṁ಴- 䉦䉸䊷䊄⴫㕙䈪૗䈏⿠䈖䈦䈩䈇䉎䈱䈎䇮䈬䈱䉋䈉䈮ṁ಴䈏ଦㅴ䈘䉏䉎䈱䈎䈠䈱⴫㕙෻ᔕ䈱⹦⚦䈲ో䈒⸃᣿䈪䈐䈩䈇䈭䈇䇯- ᄢ㊂䈱᳓䈏ሽ࿷䈜䉎in-situ᧦ઙ䈪䈱᭴ㅧ⸃ᨆ䈏ᔅ㗇䇯anodeΆᢱ㔚ᳰ䉶䊦䈱㔚࿶ᄌൻᤨ䈱㔚᳇⊛෻ᔕ㔚࿶ᄌൻ䈪䉶䊦䉕ᵹ䉏䉎㔚ᵹ䈲䇮ᢙ⑽䈪䉷䊨䈮⥋䉎䇯
Pt LIII ┵䈱QXAFS᷹ቯ䈮䈲䇮ᦨૐ䈪䉅15⑽䈏ᔅⷐ䇯
Voltage
1.0 V Trigger

delay
t

T1

ᤨ㑆ಽ⸃⢻䈱
ะ਄䈏ᔅⷐ

T2

Waiting
trigger

P/GP/G statstat(2) EXAFS (TG-QXAFS)- Pt-Pt㈩૏ᢙ (☸ሶᓘ䉕෻ᤋ)- Pt-O㈩૏ᢙ (⴫㕙䈱OH䈱ᢙ, Ptᓸ☸ሶ䈱ṁ಴䉕෻ᤋ)- Pt-Pt, Pt-O䈱⚿ว〒㔌Æ Ptᓸ☸ሶ䈱਄䈱⴫㕙෻ᔕ䈮䈧䈇䈩䈱ᖱႎÆ Ptᓸ☸ሶ䈱቟ቯᕈ䋨ṁ಴䋩䈮䈧䈇䈩䈱ᖱႎ

QXAFS
QXAFS

t2=15 s

Time

t=0

QXAFS
QXAFS spectrum
spectrumforfor 1515 ss

Combining
15 fragments of QXAFS(3) Potentiostat- Άᢱ㔚ᳰ䉶䊦䉕ᵹ䉏䉎㔚ᵹ䈱ᄢ䈐䈘䊶ᤨ㑆ᄌൻÆ 㔚ᭂ⴫㕙䈪䈱㔚᳇ൻቇ෻ᔕ (㔚ሶ⒖േ) 䈱ㅦᐲ(㔚᳇2㊀ጀ䈱ᒻᚑ, Ptᓸ☸ሶ䈱Ꮺ㔚䈭䈬䋩

TG-QXAFSTG-QXAFS forfor 11 ss

Time-Gating QXAFSᴺ䈮䉋䉎Άᢱ㔚ᳰ⿠㔚ᤨ䈱
Pt/C䉦䉸䊷䊄⸅ᇦ䈱ᤨ㑆ಽ⸃᭴ㅧ⸃ᨆ
㔚ᳰOFF (0.4 Æ 1.0 V)
ChargeCharge(P/G(P/G stat)
stat)

0.8

Άᢱ㔚ᳰ⿠㔚ᤨ䈮䉦䉸䊷䊄⴫㕙䈪⿠䈖䉎෻ᔕᯏ᭴䉕⸃᣿

0.5

-

0.6

Charge /CPt
Pt valence
valence (XANES)(XANES)

0.4

OH OH- HOHO- - OHHOHO- - OH OH
OH
OH- OH OHHO HO HOOH

-0.4

Pt valence

0.7
0.4

Pt valence

Charge /C

Pt charging-1
Pt-O formation kd=0.011 s
kPt-O=0.013 s-1

0.0

-0.2
0.6

0.3

-0.6

1.0
1.0 V
V

㔚ᳰOffㆊ⒟㔚ᳰON (1.0 Æ 0.4 V)

0.9
0.8

0.2

e- transfer

e- transfer

-0.8

0.5

0.1

20

40

60

80

100

120

0

20

40

Time /s

0.5

7
6

0.0
40

60

Time /s

80

100

120

CN (Pt-Pt)

CN (Pt-Pt)

1.0

CN
CN (Pt-O)(Pt-O)

2.0
1.5

9
1.0
8
0.5

7
6

0.0
0

20

40

60

Time /s

80

100

120

CN (Pt-O)

920

ke1=0.39 s-1
HOHH
H H OH HOHH
HHOHO HHOHO H OHH
OH OH
H OH
H
OH
H H
HO
HO OH
H H
HO
OH
H

120

10

CN (Pt-O)

1.5

0

100

11

2.0

10

8

80

Time /sCN
CN (Pt-Pt)(Pt-Pt) (EXAFS)(EXAFS)

11

60

OH
OH
HOHO
OH
HOHO
OH OH OHOH
HO HO HO OH OH
OH

k’e2=0.17 s-1

e- transfer

0.0

OH
OH
HOHO
OH
HOHO
OH OH OHOH
HO HO HO OH OH
OH

e- transferk’e1=2.86 s-1

Pt-O dissociationk’Pt-O=0.39 s-1

ke2=0.049 s-1

0.2

0SPring-8
BL01B1

AIR(1) XANES (TG-QXAFS, DXAFS)- Pt d ゠㆏䈱㔚ሶኒᐲ (Ptଔᢙ䈮⋧ᒰ)Æ Ptᓸ☸ሶ⸅ᇦ䈱Charging/discharging

Finisht1

MC
H2 N2 AIR

In-situ XAFS᷹ቯ䈎䉌Άᢱ㔚ᳰ䈮㑐䈜䉎䈬䈱䉋䈉䈭ᖱႎ䈏ᓧ䉌䉏䉎䈎?

0.4 V
Start

MC
H2

Fuel
Fuel cell
cell
SystemSystemTime-Gating Quick XAFS (TG-QXAFS)

Ion chamber(I)

Ion chamber(I0)

Pt discharging
k’d=0.039 s-1

0.4
0.4 V
V

㔚ᳰOn(⊒㔚)ㆊ⒟-OH OH-HOHOOH
HOHO- - OH OH OH
OH- OH OHHOHO HOOHᤨೞታ↪Άᢱ㔚ᳰ䈱⿠㔚ㆊ⒟䈮䈍䈔䉎8䈧䈱⚛ㆊ⒟ో䈩䈱෻ᔕㅦᐲቯᢙ䉕᳿ቯ䇯ታ↪Άᢱ㔚ᳰ䈱⿠㔚ㆊ⒟䈮䈍䈔䉎8䈧䈱⚛ㆊ⒟ో䈩䈱෻ᔕㅦᐲቯᢙ䉕᳿ቯ䇯䈖䉏䉁䈪หᤨ䈮⿠䈖䉎䈫⠨䈋䉌䉏䈩䈐䈢㔚᳇ൻቇ෻ᔕ䈫⸅ᇦ⥄り䈱᭴ㅧᄌൻ䈖䉏䉁䈪หᤨ䈮⿠䈖䉎䈫⠨䈋䉌䉏䈩䈐䈢㔚᳇ൻቇ෻ᔕ䈫⸅ᇦ⥄り䈱᭴ㅧᄌൻ䈱㑆䈮䇮᣿⏕䈭ᤨ㑆Ꮕ䈏ሽ࿷䈜䉎ᣂ䈚䈇⃻⽎䉕⊒⷗䇯䈱㑆䈮䇮᣿⏕䈭ᤨ㑆Ꮕ䈏ሽ࿷䈜䉎ᣂ䈚䈇⃻⽎䉕⊒⷗䇯㸫㸫

㔚࿶Ⴧടᤨ䈱Pt䉦䉸䊷䊄⸅ᇦഠൻ䉕᷹ⷰ
ChargeCharge(P/G(P/G stat)stat)䉦䉸䊷䊄㔚ᭂ⴫㕙䈪⿠䈖䉎Pt⸅ᇦṁ಴䈱৻࿃䉕⸃᣿

CN
CN (Pt-Pt)(Pt-Pt)(EXAFS)(EXAFS)

11

1.4

1.0
0.8

CN (Pt-Pt)

Pt
Pt valence
valence(XANES)(XANES)

1.0

0.5

1.5

9
1.0
8
0.5

7

0.6

CN
CN (Pt-O)(Pt-O)0.0

6

0.0
0

50

< 500 ms
䈱ೋᦼㆊ⒟

100

0

150

50

100

150

Time /sTime /s

Pt-Pt dissociation kPt-Pt = 0.031 s-1
Pt-O formation
kPt-O = 0.026 s-1

0.75

CN (Pt-O)

1.2

e- transfer
H
OH H
OH
H H
H
HO OH
OH
H
H
H
HO HO
OH H
OH
H
OH
H OH
H
H
H
OH
OH
HO
OH
H
H
HO
OH
H

-

-

HO
-

HO

HO

-

-

-

-

OH

-

-

-

OH

OH

OH

OH

HO HO

OH
-

-

OH

0.65
0.60

<500
<500 ms䈱ೋᦼㆊ⒟䈱
ms䈱ೋᦼㆊ⒟䈱
Pt⸅ᇦ䈱᭴ㅧᄌൻ䉕Pt⸅ᇦ䈱᭴ㅧᄌൻ䉕䊥䉝䊦䉺䉟䊛ⷰኤ䈜䉎䈖䈫䊥䉝䊦䉺䉟䊛ⷰኤ䈜䉎䈖䈫
䈮䉅ᚑഞ䇯
䈮䉅ᚑഞ䇯

0.4
0.4 VV ÆÆ 1.4
1.4 VV

0

100

200

300

400

OH
OH
-OH
HO OH
HO HO O OH O
OH
OH
OH
OO
O OH
OH
HO HO
OH
OH
O
O

kPt-O=0.026 s-1
kPt-Pt=0.031 s-1

OH

OH

HO

OH O
OH
O
O
OH
O OHO OH
O OH
OH O
O
O
O
OH
OH
HO HO
O
OH
OHO
O
O O O

HO

kXANES=0.010 s-1䉶䊦㔚࿶䈏Ⴧട䈜䉎䈫䇮Ptᓸ☸ሶ⴫㕙䈱Pt-Pt⚿ว䉕ಾᢿ䈚䈩䇮䉶䊦㔚࿶䈏Ⴧട䈜䉎䈫䇮Ptᓸ☸ሶ⴫㕙䈱Pt-Pt⚿ว䉕ಾᢿ䈚䈩䇮㉄⚛ේሶ䈏⴫㕙╙2ጀ䈮ẜ䉍ㄟ䉃䇯㉄⚛ේሶ䈏⴫㕙╙2ጀ䈮ẜ䉍ㄟ䉃䇯ᤨ㑆ಽ⸃⢻:
ᤨ㑆ಽ⸃⢻: 44 ms
ms

0.45

-

OH

1.4
1.4 V
V
Pt charging

ke2=0.040 s-1

0.55
0.50

OH

-

䉣䊈䊦䉩䊷ಽᢔဳDXAFS䉣䊈䊦䉩䊷ಽᢔဳDXAFS

1.4
1.4 VV ÆÆ 0.4
0.4 VV

H+

OH OH

OH

-

ke1=0.40 s-1

0.70

Pt valence

Pt-O formation
Pt-Pt dissociation
e- transfer

0.4
0.4 V
V

2.0

10

1.5

Pt valence

Charge /C

2.0

䈖䈱ㆊ⒟䈏➅䉍㄰䈘䉏䉎䈫䇮Ptᓸ☸ሶ⴫㕙䈎䉌Pt䈏೸㔌䈚䈩䇮䈖䈱ㆊ⒟䈏➅䉍㄰䈘䉏䉎䈫䇮Ptᓸ☸ሶ⴫㕙䈎䉌Pt䈏೸㔌䈚䈩䇮ṁ಴䋨⸅ᇦഠൻ䋩䈏ㅴⴕ䈜䉎䇯ṁ಴䋨⸅ᇦഠൻ䋩䈏ㅴⴕ䈜䉎䇯
Angew. Chem. Int. Ed. 46, 4310 (2007).

Time /ms

CZ (Ce22Zr22Oxx) 䈱᭴ㅧ⥄േゞឃ䉧䉴ᵺൻ⸅ᇦ䈱㉄⚛ๆ⬿//᡼಴ㆊ⒟䈱⸃᣿
OSC value: 1506 Pmol O / g

Angew. Chem. Int. Ed. 46, 9253 (2007).

TOYOTA CRDL. INC.

OXYGENOXYGEN STORAGE
STORAGE|FT|[k 3 F(k)]64vacant
site

12

2

8

Ce

0
0

1

4
2

R /10 -1 nm

3time / s
4

0

5

Zr

2007ᐕ12᦬17ᣣ ᦺᣣᣂ⡞Ce
Ce22Zr
Zr22O
O77

Ce
Ce22Zr
Zr22O
O88
N-phase (Fluorite-type)(lattice parameter: 0.526 nm)
Ce4+: 0.097 nm

Pyrochlore-type structure(lattice parameter: 0.537 nm)
Ce3+: 0.114 nm
cf. Zr4+ 0.084 nm; O2- 0.138 nm㉄⚛᡼಴ㆊ⒟䈱Ce LIII
┵ᤨಽഀDXANES
III
with 1 wt% Pt
573 K
H2 12.4 kPa
2.0Pt᳓⚛ㆶర䈮䉋䉎
᳓⚛ㆶర䈮䉋䉎CZ
CZ㉄⚛᡼಴ㆊ⒟䈱
㉄⚛᡼಴ㆊ⒟䈱
Ce
Ce䈱ᄌൻ䉕
䈱ᄌൻ䉕300
300 msmsᲤ䈮䊥䉝䊦䉺䉟䊛ㅊ〔Ფ䈮䊥䉝䊦䉺䉟䊛ㅊ〔1.5Ce
Ce22Zr
Zr22O
O77

䎔䎑䎓

Ce4+

䎓䎑䎙
䎓䎑䎗
䎓䎑䎕
䎓䎑䎓
䎔䎑䎓

Ce
Ce22Zr
Zr22O
O88

1.0

5720

5740

5760

5780

㉄⚛ๆ⬿
Ce3+

Ce4+

䎓䎑䎙
䎓䎑䎗

䎓

䂾 773 K
䂦 673 K
䂔 573 K䎕䎗䎙Time / s㸫㸫

Ce3+

3+
Ce
෻ᔕ㐿ᆎ
11 ssએౝ䈮෻ᔕ㐿ᆎએౝ䈮Oxidation of Pt/Ce2Zr2O7
O2: 12.4 kPa

䎓䎑䎓Energy / eV

Ce4+

90%
90%䈱
䈱Ce
Ce䈱ଔᢙ䈏ᄌൻ䈱ଔᢙ䈏ᄌൻ

䎓䎑䎛

䎓䎑䎕
0.5
5700

㉄⚛᡼಴

Reduction of Pt/Ce2Zr2O8
H2: 12.4 kPa䎓䎑䎛

Coefficient㉄⚛᡼಴Coefficient2.5㉄⚛ๆ⬿/᡼಴ㆊ⒟䈱Ce LIII┵DXANES䈱⸃ᨆIII
Fobs = C1 F Ce3+) + C2 F (Ce4+)
for Ce L3-edge XANES spectra
Coefficient (C2)

Ce4+

Coefficient (C1)

Ce3+

䎛

䎔䎓

䎔䎕

㉄⚛᡼಴ㆊ⒟䈱Zr K┵ᤨಽഀDXAFS
Ce2Zr2O7

Ce2Zr2O8㉄⚛ๆ⬿/᡼಴ㆊ⒟䈱Zr K┵DXANES䈱⸃ᨆ
Fobs = C1 F Ce Zr O ) + C2 F (Ce Zr O )for the Zr K-edge XANES spectra

with
1 wt% Pt

773 K
㉄⚛᡼಴

1.6

2

Coefficient (C2)573 K
H2 12.4 kPa
1.4᳓⚛ㆶర䈮䉋䉎
᳓⚛ㆶర䈮䉋䉎CZ
CZ㉄⚛᡼಴ㆊ⒟䈮䈍䈔䉎㉄⚛᡼಴ㆊ⒟䈮䈍䈔䉎
Zr
Zr䈱ᄌൻ䉕
䈱ᄌൻ䉕22 msmsᲤ䈮䊥䉝䊦䉺䉟䊛ㅊ〔Ფ䈮䊥䉝䊦䉺䉟䊛ㅊ〔

1.2

7

2

2

8

Ce
Ce22Zr
Zr22O
O88

Coefficient (C1)CeO
Ce22ZrZr
1.022O77

0.8
17980

18000

18020

18040

18060

Reduction Process
H2 12.4 kPa

0.8

㉄⚛᡼಴

0.6
0.4

䂾 773 K
䂦 673 K
䂔 573 K

0.2
0.0
1.0

18080

Energy / eV㉄⚛ๆ⬿Oxidation Process
O2 12.4 kPa

0.8
0.6
0.4
0.2
0.0
0

2

4

6

8

10

12

14

time / s㉄⚛᡼಴ㆊ⒟䈱Zr K┵DEXAFS

CN of Zr-O

Zr -O

䎛䎑䎓

න⊒෻ᔕ䈮䈍䈔䉎᭴ㅧᄌൻ䉕න⊒෻ᔕ䈮䈍䈔䉎᭴ㅧᄌൻ䉕22 ms
msᲤ䈮ㅪ⛯᷹ቯ䈜䉎䈖䈫䈮ᚑഞᲤ䈮ㅪ⛯᷹ቯ䈜䉎䈖䈫䈮ᚑഞ
Zr-O
Zr-O⚿ว䈱ಾᢿ⚿ว䈱ಾᢿ//ᒻᚑㆊ⒟䉕⸃ᨆ
ᒻᚑㆊ⒟䉕⸃ᨆ

㉄⚛᡼಴

䎚䎑䎓

CNof

䎙䎑䎘
䎙䎑䎓
䎘䎑䎘
䎕䎑䎕䎓
䎕䎑䎕䎓

d (Zr-O) /㷬

Acquisition time: 2 ms

䎚䎑䎘

0.220 nm䎕䎑䎔䎛Rof Zr -O/ 0.1nm

Zr-O㉄⚛ๆ⬿/᡼಴ㆊ⒟䈱
Zr K┵DEXAFS䈱⸃ᨆ䎛䎑䎘

CN = 㫧 0.7
R = 㫧 0.002 nm

䎕䎑䎔䎙
䎕䎑䎔䎙
䎕䎑䎔䎗

䎕䎑䎔䎕

0.208 nm

䎕䎑䎔䎕

䎕䎑䎔䎓
䎕䎑䎓䎛

|FT|[k 3 F(k )]

䎓

䎔

䎕

䎓

䎔

䎕

䎖

䎗

䎘

䎙

䎚

䎖

䎗

䎘

䎙

䎚

tim e / s

㉄⚛᡼಴

773 K
H2: 12.4 kPa

䎛䎑䎘

6

䎛䎑䎓

2
0
4

1

R

2

/1 0 -1

nm

3

tim e / s
4

0

5

Zr-O
Zr-O⚿ว䈱ᒻᚑ⚿ว䈱ᒻᚑ//ಾᢿ䈲䇮ಾᢿ䈲䇮
66 ss䈎䈔䈩ㅴⴕ䈜䉎䇯䈎䈔䈩ㅴⴕ䈜䉎䇯(Zr(Zr XANESXANES䈱⚿ᨐ䈫ห᭽䈱⚿ᨐ䈫ห᭽))

䎚䎑䎘
䎚䎑䎓

䎚䎑䎓
䎙䎑䎘
䎙䎑䎘
䎙䎑䎓
䎙䎑䎓
䎘䎑䎘

䎕䎑䎕䎓

8

0

CNof Zr -O
CN
of Zr-O

12

䎚䎑䎘

䎕䎑䎔䎛

d (Zr-O) /㷬4䎛䎑䎓

Rof Zr -O/ 0.1nm

Ptt

2

1.0

䎕䎑䎔䎙
䎕䎑䎔䎗
䎕䎑䎔䎕
䎕䎑䎔䎓

0.20995 nm (XRD)
䎓

䎔

䎕

䎖

䎗

䎘

䎙

䎚

㉄⚛ๆ⬿

773 K
O2: 12.4 kPatime / s㉄⚛ๆ⬿/᡼಴ㆊ⒟䈱ᵴᕈൻ䉣䊈䊦䉩䊷㉄⚛ๆ⬿(ㅦᐲቯᢙ (773 K))㉄⚛᡼಴ᤨ㑆ಽ⸃XAFS᭴ㅧ⸃ᨆ䈎䉌⷗䈧䈎䈦䈢ᣂ䈚䈇⃻⽎
kJ mol-1

20(k = 1.39 s-1)

43 (k = 2.17 s-1)

Zr XANES

4(k = 0.46 s-1)

43 (k = 0.39 s-1)

Zr EXAFS

4

Ce XANES36

䊶 Pt䈱᦭ή䈪ೋㅦᐲ䈲ᄌ䉒䉌䈭䈇䇯䊶 Ce䈱ଔᢙᄌൻ (20 kJ mol-1)
䊶 Zr-O⚿วᒻᚑ䈲⊒ᾲ෻ᔕ (Ea㻃0)䊶 Pt䈏䈭䈇䈫ㆶర䈲ᱴ䈬ㅴⴕ䈚䈭䈇䇯䊶 Ce䈫Zr䈲ห䈛Ea䊶 ㆶరㅦᐲ䈲᳇⋧H2࿶ജ䈮ଐሽ䇯

䊶䊶 25%䈱㉄⚛䈏ᶖ⾌䈘䉏䈢䈣䈔䈪25%䈱㉄⚛䈏ᶖ⾌䈘䉏䈢䈣䈔䈪3+䈏Ce
4+䈮㉄ൻ䈘䉏䉎䇯
80%䈱Ce80%䈱Ce3+
䈏Ce4+
䈮㉄ൻ䈘䉏䉎䇯

䊶䊶 40%䈱᳓⚛䈏ᶖ⾌䈘䉏䈢䈣䈔䈪40%䈱᳓⚛䈏ᶖ⾌䈘䉏䈢䈣䈔䈪
4+䈏Ce
3+䈮ㆶర䈘䉏䉎䇯
90%䈱Ce90%䈱Ce4+䈏Ce3+䈮ㆶర䈘䉏䉎䇯

O
O22䈏
䈏Pt/CZ
Pt/CZ⴫㕙䈪⸃㔌
⴫㕙䈪⸃㔌
㸣
㸣
䊋䊦䉪ౝㇱ䈮
䊋䊦䉪ౝㇱ䈮OO䈏᜛ᢔ䈏᜛ᢔ ((ᓞㅦᓞㅦ))
Zr-O
Zr-O⚿ว䉕ᒻᚑ
⚿ว䉕ᒻᚑ

Zr-O
Zr-O⚿ว䈏ಾᢿ⚿ว䈏ಾᢿ ((ᓞㅦ
ᓞㅦ))
H
H22䈏
䈏Pt
Pt⴫㕙䈪⸃㔌⴫㕙䈪⸃㔌 ((ᓞㅦᓞㅦ))㸣㸣䊋䊦䉪ౝㇱ䉕
䊋䊦䉪ౝㇱ䉕OO䈏᜛ᢔ䈚䈩
䈏᜛ᢔ䈚䈩
⴫㕙䈪
⴫㕙䈪H
H22O
O䉕↢ᚑ䊶⣕㔌䉕↢ᚑ䊶⣕㔌

(1) In-situ ᤨಽഀXAFS䈮䉋䉍䇮CZ䈱㉄⚛ๆ⬿/᡼಴ㆊ⒟䈮䈍䈔䉎Ce, Zrਔ䉰䉟䊃䈱᭴ㅧᄌൻ䉕䊥䉝䊦䉺䉟䊛⸘᷹䈚䇮ㅢᏱ䈱䉧䉴ๆ⌕䉇ᾲ㊂ಽᨆ䈭䈬䈱䊙䉪䊨䉴䉮䊏䉾䉪䈭ᖱႎ䈎䉌䈲᣿䉌䈎䈮䈪䈐䈭䈇࿕ṁ૕ౝㇱ䈱ฦ෻ᔕ䉰䉟䊃䈱䉻䉟䊅䊚䉾䉪䈭േ䈐䉕ᝒ䈋䉎䈖䈫䈮ᚑഞ䈚䈢䇯(2) ቢో࿕ṁ૕䉕ᒻᚑ䈚䈩䈇䉎‛⾰ (Ce2Zr2Ox) 䈮䈍䈇䈩䇮1䈧䈱෻ᔕ䈮㑐䉒䉎⚿᥏ౝ䈱2䈧䈱෻ᔕ䉰䉟䊃䈏หᦼ䈚䈩෻ᔕ䈚䈭䈇䈖䈫䉕⷗಴䈚䈢䇯(3) ㉄⚛ๆ⬿/᡼಴䈱䈇䈝䉏䈱ㆊ⒟䈮䈍䈇䈩䉅䇮㉄⚛෻ᔕ㊂䈏㊂⺰䈮⥋䉌䈭䈇䈱䈮䇮Ce䈱㉄ൻㆶర䈏ቢੌ䈚䈩䈚䉁䈉䈖䈫䈏䉒䈎䈦䈢䇯ㅢᏱ䈱1ኻ1䈱䉪䊤䉲䉦䊦䈭㉄ൻㆶర䈪䈲⺑᣿䈪䈐䈭䈇⃻⽎䇯㉄⚛䈱േ䈐䉕઻䈉Zr஥䈮Ce䈱㉄⚛䈏ዋ䈚᛼䈚಴䈘䉏䈢䉍䇮ᒁ䈦ᒛ䉌䉏䈢䉍䈜䉎ਛ㑆⁁ᘒ䈏ሽ࿷䈜䉎䈱䈪䈲䈭䈇䈎䋿㔚ሶ䈱᝼ฃ䈏వ䈮ᒁ䈐㊄䈮䈭䈦䈩䇮࿕ṁ૕ౝㇱ䈱㉄⚛䈏േ䈐಴䈜䇯䊶䊶䊶 䈖䈱⸅ᇦ䈏ఝ䉏䈢OSC䉕␜䈜ⷐ࿃䈪䈅䉎䈫⠨䈋䉌䉏䉎䇯㸫㸫

⻢ㄉ᧲੩ᄢቇᄢቇ㒮ℂቇ♽⎇ⓥ⑼ൻቇኾ᡹
JASRI/SPring-8
㜞↰᣽᮸ᢎ᝼䊶ቝ⇐⾐᦮຦ඳ჻⼱↰⡸ඳ჻䊶ട⮮๺↵ඳ჻᧲੩ᄢቇᄢቇ㒮Ꮏቇ♽⎇ⓥ⑼የ᎑ᱜᴦᢎ᝼
䊃䊣䉺⥄േゞᩣᑼળ␠Άᢱ㔚ᳰ㐿⊒䉶䊮䉺䊷᧛↰ᚑ੫᳁䊶ਛ⷏ᴦㅢ᳁䊶᧻ᧄା৻᳁

ጤỈᐽ⵨ᢎ᝼
KEK PF㊁᧛᣽ᴦᢎ᝼䊶Ⓑ↰ᐽብಎᢎ᝼
᧲੩ᄢቇᄢቇ㒮ᣂ㗔ၞഃᚑ⑼ቇ⎇ⓥ⑼૒䇱ᧁጪᒾಎᢎ᝼
⼾↰ਛᄩ⎇ⓥᚲᦺጟ⾫ᒾ᳁䊶ᑝ᎑৻ፏ᳁㐳੗ᐽ⾆᳁ਃ੗ൻቇ䊺⸅ᇦ⑼ቇ⎇ⓥᚲ
⮮↰ᾖౖඳ჻䊶⮮ේ⻞ੑඳ჻䊶෸Ꮉ㓉ඳ჻
᧲ᄢ㒮ℂጤỈ⎇ⓥቶ
Dr. Bal 䊶 Dr. Kantam 䊶 ⼱ᳰବ᣿ඳ჻
ጊᧄቁඳ჻䊶㋈ᧁ䈅䈎䈰ඳ჻䊶਄᧛ᵗᐔፉᧄ୶↵䊶↰ਛ㉿૫䊶ศ↰ᷕ䊶⿒Ⴆఝ૞
ಽሶ⑼ቇ⎇ⓥᚲ
Dr. Yang 䊶 Dr. Wengᧁਅ⌬㓶䊶᧛਄ᄢテ䊶⍹㤥ᔒ䊶ਠ↰␭ሶ

Funding:᧲੩ᄢቇ21਎♿COE䊶䉫䊨䊷䊋䊦COE⧯ᚻ⎇ⓥ (A), ⧯ᚻ⎇ⓥ (B)․ቯ㗔ၞ⎇ⓥ䇸දᄼᯏ⢻⸅ᇦ䇹․ቯ㗔ၞ⎇ⓥ䇸㈩૏ⓨ㑆䈱ൻቇ䇹․ቯ㗔ၞ⎇ⓥ䇸ᭂᓸ᭴ㅧ෻ᔕ䉻䉟䊅䊚䉪䉴䇹
NEDOᰴ਎ઍᛛⴚ㐿⊒੐ᬺ䊃䊣䉺⥄േゞᩣᑼળ␠ਃ੗ൻቇ䊺⸅ᇦ⑼ቇ⎇ⓥᚲ
ᣣ↥⥄േゞ✚ว⎇ⓥᚲ

㸫㸫

㑄⛣㔠ᒓ㓟໬≀ࢼࣀᵓ㐀యࡢ᭱㏆ࡢ◊✲㸦,㸧ZnOࡢ㸱D ࢼࣀᵓ㐀యࡢస〇࡜ Randomlaser Ⓨ᣺࡬ࡢᛂ⏝
Recent study on nano-structured semiconducting materials based on transition metal oxides—(1)Fabrication of 3D mamostructures of ZnO and their application to random laser emission
✀ᮧ ᴿࠊⱑ ⷣࠊ᳿ ្㢒ࠊ๽ ᶞᖹ㒯 ᫂Ụ
S. Tanemura1,2*, L. Miao2,1, H.Y. Yang4, S.P. Lau4, B.K. Tay4㸦㈈㸧ࣇ࢓࢖ࣥࢭ࣑ࣛࢵࢡࢫࢭࣥࢱ࣮ࠊᮦᩱᢏ⾡◊✲ᡤ୰ᅜ⛉Ꮫ㝔 ᗈᕞ࢚ࢿࣝࢠ࣮◊✲ᡤࢩ࣏࣮ࣥ࢞ࣝ༡ὒᕤ⛉኱Ꮫ 㟁Ẽ࣭㟁ᏊᕤᏛ⛉ࠊThe semiconductor oxide materials, e.g., ZnO and TiO2, have attracted much attention over decades due to theirunique advantages: stable, inexpensive, wide band gap and etc. These unique properties lead to various novel
applications which different from conventional semiconductors greatly: photo-induced reactivity [1], optoelectronic
device [2-3], solar cell [4-5], smart windows [6] and etc. To prepare these semiconductor oxides in nanometer-scale
and to find the novel optical properties of the prepared nano-materials different from those of conventional bulk
materials should contribute to the development of innovative nano-systems and nano-structured materials.
In our laboratory, we recently focused on the synthesis, optical properties and novel applications of ZnO. Several
kinds of nanostructures: nano-films[7-12], nanobamboos[13], nanorods[14,15], and nanowalls[16-19] were fabricatedby either physical or chemical methods. In this presentation, we highlight the accomplishment on 3D nano-wall ZnO[16-19].
A solid-vapor phase thermal sublimation technique was employed to fabricate low-cost and mass-production of
ZnO 3D random-wall structure on ZnO/SiO2/Si substrate without any catalyst and additive in tube furnace as shown in
Fig.1. We prepared 3 samples by following the conditions listed in Table 1, where Tp: the temperature of mixed
powder at the bottom of the tube; Ts: the temperature of substrate; Tdep: deposition time; ZnO: C: the weight percentage
for raw materials ZnO powder and carbon powder; Ptol: base pressure under the evacuation of the tube furnace, and O2:
introduced oxygen rate. The oxygen flow rate was 150ml/min. The substrates (ZnOfilm/SiO2/Si) were used.
“Patterning” in Table1 means that we used Cu-mesh mask in sputtering process for top thin layer of ZnO.

Fig.1. Schematics of the tube furnace used for the fabrication of ZnO nanostructure.

SampleName.
A
B
C

Table 1. Typical fabrication conditions of samples A, B and C.
Tp/Ts (oC)
ZnO: C Oxygen flow
Tdep
Patterning(mg)(ml/min)(min)
1000/630
500:20150
30
X1000/730
500:2015030‫ۑ‬1000/730
500:20150
30
X

Figure 2 shows the SEM images of three samples. Except sample C, Samples A and B display vertically [001]grown nanorods with hexagonal end planes, averaged diameters in about 100~200 nm, and the length ranging from500~1700 nm. Although the substrate temperature is slightly different, the morphology difference of sample B fromthat of sample A is the patterned c-axis growth of rods. The coalescence of several rods is apparent in sample A.
Although three samples show very strong and narrow near band edge emission centered at 380 nm in wavelength㸫㸫

(a)

(b)

(d)

(c)

500nm

200n
Fig. 2. SEM images of ZnO nanostructures synthesized in the conditions listed in Table 1. (a) nanorods in Sample A;(b) low-magnified image of nanorods with mesh patterning in Sample B and insert high magnified-image; (c) 3-D
random-wall nano structure in Sample C; (d) cross-sectional and tilted SEM images of 3-D random wall nanostructurein Sample C. The cavities with 20-200 nm in diameters are holed throughout the layer. The wall has irregular heightfrom 250-95 nm.
without any broad green band emission centered at 500nm, no lasing action was observed except a single broad
spontaneous emission peak (amplified spontaneous emission: ASE) with a full width at half maximum of ~ 20 nm forsamples A and B under high power pumping as 0.8MW/ cm2. Random laser action with strong coherent feedback has
been firstly observed at the wavelength between 375 nm- 395 nm under 355 nm optical excitation with thresholdpumping intensity 0.38 MW/cm2 in sample C with ZnO 3-D random-wall nanostructure as shown in Fig.3 There is no
significant difference between TE and TM mode in randomlasing.

a.

Pumpinga: 0.8MW/cm

Sam ple 32

b : 0.5MW/cm 22

Output Intensity (a.u)

c: 0.38M W/cm
d: 0.20M W/cm 2

a
b
c
d
360

370

380

390

400

410

W avelength (nm)Fig.3. (a) Evolution of emission spectra of sample C (ZnO 3D random walls) under different pump intensities (frombottom: 0.20, 0.38, 0.50, and 0.80 MW/cm2). Holizontal axis: wavelength in nm, and vertical axis: out put intensity ina.u. ; (b) Output light- pumped light curves.
References[1] O. Carp, C. L. Huisman, A. Reller, Progress in Solid State Chemistry 32 (2004) 33.
[2] S. J. Pearton, D.P. Norton, K. Ip, Y. W. Heo, T. Steiner, Progress in Mater. Sci., 50(2005) 293.
[3] A E J. Gonzalez and S G. Santiago, Semicond. Sci. Technol. 22, 709 (2007).
[4] O’Regan B, Gra¨tzel M. Nature 353 (1991)737.
[5]

W. J. E.

Beek,

M. M.

Wienk,R. A. J.

Janssen,Adv.

Mater.

16(2004)1009.

[6] P. Jin, L. Miao, S. Tanemura, G. Xu, M. Tazawa, K. Yoshimura, Appl. Surf. Sci.212-213 (2003) 775.
[7] Y. G. Cao, L. Miao, S. Tanemura, and M.Tanemura, Adv. Material Res., 11-12 (2006) 159-162[8] Y.G. Cao, L.Miao, S.Tanemura, M.Tanemura, Y.Kuno, Y.Hayashi, Y.Mori, Jap. J. Appl. Phys,45 (2006) 1623-1628[9] Y.G. Cao, L.Miao, S.Tanemura, M.Tanemura, Y.Kuno, Y.Hayashi, Appl. Phys. Lett. 88 (2006) 251116 1-3[10] F.Y. Ran, L. Miao, Y. G..Cao, S. Tanemura, M. Tanemura, Trans MRS Jpn. 33[4] (2007) 1247-1250[11] L.Miao, S. Tanemura, M.Tanemura, S.P.Lau, B.K.Tay, J.Materials Science, Materials in Electronics, DOI 10 (2007) S343-346[12] F.Y.Ran, L.Miao, S.Tanemura, M.Tanemura, Y.G.Cao, S.Tanaka, N.Shibata, Materials Sci. & Enginrg., B148 (2008) 35-39[13] L.Miao, S.Tanemura, M.Tanemura, Y.Hayashi, R.P. Wang, S.Toh, K.Kaneko, Int. J. of Modern Physics 19 (2005) 2804-2810[14] L. Miao Y. Ieda, S. Tanemura, M. Tanemura, Y. Hayashi, S. Toh, K. Kaneko, S. P. Lau and B. K. Tay, Sci. Tech. Adv. Material
8 ((2007) 443-447[15] X.H.Zhang, S.J. Chua, A.M.Yong, H.Y.Yang, S.P.Lau, F.Yu, X.W. Sun, L.Miao, M.Tanemura, S.Tanemura, Appl. Phys. Lett,
90 (2007) 13107[16] L.Miao, S.Tanemura, Y.Ieda, M.Tanemura, Y.Hayashi, H.Y.Yang, S.P.Lau, B.K.Tay, Y.G.Cao, Surface Sci., 601 [13] (2007)
2660-2663[17] S.Tanemura, L.Miao, M.Tanemura, F.Y.Ran, Y.G.Cao, H.Y.Yang, S.P.Lau, Proc. IEEE Nano Elecronics Conference (IEEE
NEC) 08 , (2008) 58-63[18] L. Miao , S. Tanemura*, H.Y. Yang, S.P. Lau, J. Nano tech. (2009), (in printing).
[19] L.Miao, S.Tanemura, H.Y. Yang, S.P. Lau, G.Xu, Phys. Status Solidi C (2009) (in printing)㸫㸫

The 111th HVME Seminar
9th March 2009, Kyusyu Univ.

Our Publication Lists on this Subject
JFCC
JFCC

JFCC
JFCC
1)

Recent Study on Nano-Structured Semiconducting
Materials Based on Transition Metal Oxides-(1) Fabrication of 3D nanostructures of ZnO and theirapplication to random laser emision
Sakae TANEMURA*
L. Miao2),
H.Y. Yang3), S.P. Lau3)䇮B.K.Tay3)*Japan Fine Ceramics Centre, Nagoya, Japan
2)Key Lab. Renewable energy & Gas hydrate,
Gangzhou Inst. Energy Conversion, CAS, China
䋳䋩Electric & Electronic Dept., Nanyang Tech. Univ, Singapore
1

L. Miao Y. Ieda, S. Tanemura, M. Tanemura, Y. Hayashi, S. Toh, K. Kaneko,
S. P. Lau and B. K. Tay“Synthesis, microstructure, and photoluminescence of well-alighned ZnOnanorods on Si substrates”
Sci. Tech. Adv. Material 8 ((2007) 443-447
䋲) L.Miao, S.Tanemura, Y.Ieda, M.Tanemura, Y.Hayashi, H.Y.Yang, S.P.Lau,
B.K.Tay, Y.G.Cao“Synthesis,morphology, and random laser action of ZnO nanostructure”
Surface Sci., 601 [13] (2007) 2660-2663
䋳) X.H.Zhang, S.J. Chua, A.M.Yong, H.Y.Yang, S.P.Lau, F.Yu, X.W. Sun, L.Miao,
M.Tanemura, S.Tanemura
Linewidth dependence of exciton radiative lifetime in ZnO nanorods
Appl. Phys. Lett, 90 (2007) 13107
4) S.Tanemura, L.Miao, M.Tanemura, F.Y.Ran, Y.G.Cao, H.Y.Yang, S.P.Lau“Synthesis, Optical properties, and Functional Applications of ZnO Nanomaterials: A Review”,
Proc. IEEE Nano Elecronics Conference (IEEE NEC) 08, pp58-63.
5) L. Miao , S. Tanemura*, H.Y. Yang, S.P. Lau,
“Synthesis and random laser application of ZnO nano-walls: Review”
J. Nano Tech. (in printing) (2009)6) L.Miao, S.Tanemura, H.Y. Yang, S.P. Lau, G.Xu
“Random laser action in 3-D ZnO nanostructures”
2
Phys. Stat. Solidi, C (in printing) (2009)

Research background (1)ZnO characteristics and Possible applications

Presentation Content
JFCC
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Short wavelength
optoelectronic applications(LED (wide band), Laser)

Wide band gap
semiconductor (3.37eV)

1.Research background2.Fabrication of ZnO nano rods and 3-D nanorandom-wall by a chemical reaction/vapor transportation deposition method
3. Characterization of Optical properties :Photonic material in
the blue-UV region

High exciton binding energy(60meV> room temp.)Æ
High amplitude gain
Easy induced emission

9PL spectra;
9Random laser action by Nd:YAG䋨355nm䋩 excitation;
9Mueller matrix ellipsometry analysis;
9Polarization

JFCC

Mechanical actuators andpiezoelectric sensor/transducer

Piezoelectric and pyroelectric
properties

Transparent electrode for
Display and/or PV

High transmittance3

4

On Random lasing

References on ZnO random lasing
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JFCC

Random lasing is not usual lasing action occurred by amplitude gain of light travelingbetween two forwarding mirrors, but by closed-loop scattering through inhomogeneously
distributing media and coherent amplification of light. This laser is emitted spherically indirection. Physical mechanism such as quantum confinement of the excited electrons andexcitons, enhancement of DOS near band edge, and accelerated recombination of excitonsand electrons by light emission might be assisted.

䋱䋩㪤㪅㪟㪅㪟㫌㪸㫅㪾 㪼㫋㩷㪸㫃㪃 㵰㪩㫆㫆㫄㪄㪫㪼㫄㫇㪼㫉㪸㫋㫌㫉㪼㩷㪬㫃㫋㫉㪸㫍㫀㫆㫃㪼㫋㩷㪥㪸㫅㫆㫎㫀㫉㪼 㪥㪸㫅㫆㫃㪸㫊㪼㫉㵱㪃㩷㪪㪺㫀㪼㫅㪺㪼㪃㩷㪉㪉㪐㪉㩿㪉㪇㪇㪈㪀㩷㪈㪏㪐㪎㪃㩷㪭㪸㫇㫆㫉㩷㫇㪿㪸㫊㪼㩷㫋㫉㪸㫅㫊㫇㫆㫉㫋㪸㫋㫀㫆㫅㩷㫄㪼㫋㪿㫆㪻㩷㫆㫅㩷㪘㫌㩷㫋㪿㫀㫅㩷㪽㫀㫃㫄㩷㪺㪸㫋㪸㫃㫐㫊㫀㫊㪆㫊㪸㫇㪿㫀㫉㪼㪃㩷㫎㫀㫉㪼㩷㪻㫀㪸㫄㪼㫋㪼㫉㪑㩷㪉㪇㪄㪈㪌㪇㫅㫄㪃㩷㫃㪼㫅㪾㫋㪿㪑㩷㪉㪄㪈㪇㫌㫄㪅㩷㫋㫎㫆㩷㫅㪸㫋㫌㫉㪸㫃㫃㫐㩷㪽㪸㪺㪼㫋㪼㪻㩷㪿㪼㫏㪸㪾㫆㫅㪸㫃㩷㪼㫅㪻㩷㪽㪸㪺㪼㫊㩷㫆㪽㩷㪼㫇㫀㫋㪸㫏㫀㪸㫃㫐 㪾㫉㫆㫎㫅㩷㪱㫅㪦 㪸㪺㫋㫀㫅㪾㩷㪸㫊㩷㫄㫀㫉㫉㫆㫉㫊㪅㩷䋲䋩㪪㪅㪝㪅㪰㫌 㪼㫋㩷㪸㫃㪃㩷㵰㪩㪸㫅㪻㫆㫄 㫃㪸㫊㪼㫉㩷㪸㪺㫋㫀㫆㫅㩷㫀㫅㩷㪱㫅㪦 㫅㪸㫅㫆㫉㫆㪻 㪸㫉㫉㪸㫐㫊㩷㪼㫄㪹㪼㪻㪼㪻 㫀㫅㩷㪱㫅㪦㪼㫇㫀㫃㪸㫐㪼㫉㫊㵱㪃㩷㪘㪅㪧㪅㪣㪅㩷㪏㪋㩿㪉㪇㪇㪋㪀㩷㪊㪉㪋㪈㪄㪊㪉㪋㪊㪃㩷㪤㪦㪭㪧㩷㪼㫇㫀㫋㪸㫏㫀㫐 㫄㪼㫋㪿㫆㪻㩷㫆㫅㩷㫊㪸㫇㪿㫀㫉㪼㪆㪤㪾㪦㩿㪎㪇㪇㫅㫄㪀㪆㪱㫅㪦㩷㪽㫀㫃㫄㩿㪉㪇㪇㫅㫄㪀㩷㪸㫋㩷㪋㪇㪇㩷㷄㪃㩷㪻㫀㪸㫄㪼㫋㪼㫉㪑㩷㪎㪇㫅㫄㪃㩷㫃㪼㫅㪾㫋㪿㩷㪉㫌㫄㪃㩷㪈㪅㪎㫏㪈㪇㪈㪈㫅㪸㫅㫆㫉㫆㪻㫊㪆㪺㫄㪉㪅䋳䋩㪪㪅㪧㪅㪣㪸㫌 㪼㫋㩷㪸㫃㪃㵱㪣㪸㫊㪼㫉 㪸㪺㫋㫀㫆㫅㩷㫀㫅㩷㪱㫅㪦㫅㪸㫅㫆 㫅㪼㪼㪻㫃㪼㫊㪑㩷㪺㫆㫅㪼㩷㪸㫅㪾㫃㪼㩷㪉㪇㫆㪃㩷㪈㪇㪇㪄㪱㫅㪦 㫅㪸㫅㫆㫅㪼㪼㪻㫃㪼㫊 㫊㪼㫃㪼㪺㫋㫀㫍㪼㫃㫐㩷㪾㫉㫆㫎㫅㩷
ZnO
㪉㪇㪇㫅㫄㩷㫀㫅㩷㫄㫀㪻㪄㪻㫀㪸㫄㪼㫋㪼㫉㪃㩷㪉㪇㪇㪄㪋㪇㪇㫅㫄㩷㫀㫅㩷㫆㫅㩷㫊㫀㫃㫀㪺㫆㫅㩷㪸㫅㪻㩷㫇㫃㪸㫊㫋㫀㪺㩷㫊㫌㪹㫊㫋㫉㪸㫋㪼㫊㵱㪃㩷㫃㪼㫅㪾㫋㪿㪃 㪊㪅㪇㬍㪈㪇㪏㪆㪺㫄㪉 㫀㫅㩷㪻㪼㫅㫊㫀㫋㫐㪘㪅㪧㪅㪣㪅㪃㪏㪎㩿㪉㪇㪇㪌㪀㩷㪇㪈㪊㪈㪇㪋 , 㪘㫉㪂㩷㪠㫆㫅㩷

Initial works on random laser action
N. M. Lawandy et al, “Laser action in strongly scattering
media”,Nature, 368 (1994) 436:Colloidal solution containing
rhodamine 640 perchlorate dye in methanol and TiO2
(rutile)㪹㫆㫄㪹㪸㫉㪻㫄㪼㫅㫋㩷㫄㪼㫋㪿㫆㪻㩷㫆㫅㩷㪱㫅㪦 㫋㪿㫀㫅㩷㪽㫀㫃㫄㩷㩿㪌㪉㪇㫅㫄㪃㩷㪹㫐㩷㪝㪚㪭㪘㪀㪆㫇㫃㪸㫊㫋㫀㪺㩷㪽㫀㫃㫄㩷㫆㫉㩷㪱㫅㪦㩿㪊㪇㪇㫅㫄㪃㩷㪹㫐㩷㪝㪚㪭㪘㪀㪆㪪㫀㪦㪉㩷㩿㪉㪇㪇㫅㫄㪀㩷㪆㪪㫀 㪸㫋㩷㫉㫆㫆㫄㩷㫋㪼㫄㫇㪅On ZnO random laser:
H. Cao et al: Phys. Rev. Lett, 82(1999) 2278, 84(2000) 5584,
ZnO particles is excited by Nd:YAG laser( O =355nm )threshold energy(562kW/cm2),
5

FCVA:Filtered Cathodic
Vacuum Arc method㸫㸫SiO2
Si

Closed-loop path light scattering

6

Random lasing by ZnO nano-structure

Fabrication method for ZnO nano-optoelectronics
JFCC

ZnO䋺promising for UV laser
But䊶䊶䊶

Reported methods

䇺Random laser䇻 䊶䊶䊶 No requirement for p-n junction
ZnO

Nd:YAG laser(

JFCC

It is difficult to gethigh quality p-type

1.Filtered Cathodic Vacuum Arc (FCVA)
2.Molecular Beam Epitaxy (MBE)
3.Metalorganic Chemical Vapour deposition
4.Pulsed Laser Deposition (PLD)

O =355nm )SiO2Limitations:Si

Necessary needs:
Output emission

5.Ion bombardment (seeds/corn processing) at
R.T.
Complicated vacuum equipment
Expensive substrate
Low-cost, high quality thin film or nanostructures
A chemical reaction/vapor transportation deposition

We proposed: method in a tube furnace to fabricate low-cost andClosed-loop path light scattering

Closed-loop scattering and coherent
amplification of incidental lightmass-production of ZnO nano-rods/3-D random-wallstructure on ZnO/SiO2/Si substrate without any
8catalyst and additive.

Lasing!
7

Experimental (TCR/VTD)

Synthesis conditions for lasing ZnO nanostructures
depending on substrate conditions

JFCC

JFCC

The schematic diagram of the horizontal furnace
heater

N2 gas
to
pump

O2gas

Gas flowSamplesZnO film(300nm)/SiO2/Si

T p./T s. (oC)T dep.(min)ZnO:C(mg)

Ptol
(Pa)

O2
(ml/min)Sample 1:smoothsurface

1000/63030

500:2040

150

Sample 2: roughsurface

1000/73030

500:2040

150

ZnO nanorods
ZnO,Graphite
quartz tube
substrate
heaterExperimental parameters being optimized after tremendous experiments whichbeing performed by various set of parameters.

non direct heating zone
Parameters:

Note: Tp: the temperature of mixed powder; Ts: the temperature of substrate;
Tdep: deposition time; ZnO: C: the weight percentage for raw materials ZnO
powder and carbon powder; Ptol: total pressure;

The ratio of ZnO:C, The temperature of mixed raw materials, the temperature of
substrate, gas flow, deposition time, reaction gas, catalyst, substrate

FE-SEM image and PL of ZnO nanorods arrays
grown on ZnO film (300nm) (sample 1, 630㷄䋩

910

FE SEM image of ZnO nanostructure grown on
ZnO film (730㷄䋩(sample 2)

JFCC

JFCC

380nm
PL intensity (a.u.)

Strong near band edge emission

Weak emission from oxygen
vacancy

3500

4000

4500
5000
Wavelength (Å)

5500

6000

500nm
500nm

Range: 60-350 nm
Length:500-700 nm

㫆㫌㫋㫇㫌㫋㩷㫇㫆㫎㪼㫉㩿㪸㪅㫌㪅㪀

Diameter:

No lasing !!

㪊㪍㪇

㪊㪎㪇

㪊㪏㪇

㪊㪐㪇

㪋㪇㪇

200nm

Cross-sectional and tilted SEM
The top view of SEM image shows quite
images of 3-D random walldifferent in morphology. Any isolated
nanostructure. The wall has
nanorod is not observed, and the nanorods
grown along c-axis are coalesced to form the irregular height from 250-95 nm .
honeycomb wall with 80~100 nm in thickness.

㪋㪈㪇㫎㪸㫍㪼㫃㪼㫅㪾㫋㪿㩿㫅㫄㪀11㸫㸫

Honeycomb-shaped 3-D
nano random-wall

12

Mueller matrix spectroscopic
ellipsometry analysis

Refractive index of ZnO nanowalls comparedwith ZnO thin films

JFCC

2.2

(a)130nm
L3

ZnO

Void (35%)

L2. 300nm

ZnO

Void
(25%)

L1. 435nm

SiO2

Buffer layer

Sub.

Si100-HOR

Si substrate

ZnO 3-D nanowalls
2.0
Refractive index (n)ZnO thin film

Dispersion formula of refractive index n(E) and k(E) for ZnO: F &B 2terms formula
Bruggemen EMT: applied for ZnO thin film and 3-D structure
Energy range: 848-429nm.
>F <M(O), 㰱M(O  <7 O 㰱7 O @F: 14.85
The thicknesses achieved by SE fit to SEM observation very well.

1.6

13

Pumping

0.86

Incidence
0.84 lightangle depend 1.6
P=Pgen

JFCC

0.88

2.6

㪇㪅㪋

㪇㪅㪌

㪇㪅㪍

㪇㪅㪎

㪇㪅㪏

㪇㪅㪐

㪉

㫇㫌㫄㫇㩷㫇㫆㫎㪼㫉㩿㪤㪮㪆㪺㫄㩷㩷㩷㩷
㪀

b
c
d
360

2.0
2.2
2.4
Photon energy (eV)

㪇㪅㪊

a

0.86
0.84

1.8

2.8

370

380

390

400

410

Wavelength (nm)When the pump power reached a threshold as high as 0.38MW/cm2, a dramatic
emission oscillation in a line width as narrow as 0.4 nm emerged from thesingle-broad emission spectra.

No polarization
15(a) Pumping power dependent Emission spectra of TE and/or TM
mode and(b) corresponding pumping laser power vs out-put laser power

JFCC

(a)
TE

TE

TM
TM

14

Threshold:0.38MW/cm2

2

0.90

P-70deg.
pgen-70deg.
p-50 deg.
pgen-50 deg.

0.88

2.8

㫆㫌㫋㫇㫌㫋㩷㫇㫆㫎㪼㫉㩿㪸㪅㫌㪅㪀

0.92

0.90

2.6

Sample 3
Coherent
feedback2

c: 0.38MW/cm
d: 0.20MW/cm 2

Output Intensity (a.u)

0.94

0.92

a: 0.8MW/cm

b: 0.5MW/cm 2

Pgen

0.94

2.0
2.2
2.4
Photon energy (eV)

Evolution of emission spectra of the ZnO 3-D
random-wall of sample 2

0.98
0.96

1.8

Compared with ZnO thin films, ZnO nanowalls has: Similar
curve shape, but lower refractive index value

JFCC

0.96

1.6

1.2

1.00
0.98

ZnO nanowalls
ZnO layer
Pure ZnO film
200 nm ZnO on SiO2

1.8

1.4

Optical polarization property of ZnO nanowall

P

JFCC

No great diference wasfound in TE and TM mode
except out-put laser power.
(b)

TE

TM

17

㸫㸫

16

Summary

JFCC

Through a simple solid-vapour phase thermal sublimation
technique :# 3-D ZnO random-wall structure and well-aligned ZnOnanorods were grown on ZnO thin film using Si substrate# Morphology is the key parameter# Closed-loop scattering and coherent amplification of lightare realized by 3-D random wall.
#Relatively lower threshold is obtained (0.38 mW/cm2)#No great difference was found in TE and TM polarization
mode of random lasing and Mueller matrix analysis.
#Compared with ZnO thin films, ZnO nanowalls shows similar
refractive index curve shape, but lower refractive index value .
Our method to fabricate mirrorless UV lasers on silicon substrate is
unique and this will make the mass production of low-cost UV lasing
sources and their integration with silicon-based electronics feasible.

18

6L216L& ㉸ⷧ⭷ᵓ㐀ࡢ㟁Ꮚ≧ែᰣཎ ᾈ
஑ᕞ኱Ꮫ⥲ྜ⌮ᕤᏛ◊✲㝔!
 ࢩࣜࢥ࣮ࣥ࢝ࣂ࢖ࢻ㸦SiC㸧ࡣ Si ࡟᭰ࢃࡿḟୡ௦ࣃ࣮࣡ࢹࣂ࢖ࢫࡢᇶᮏ≀㉁࡜ࡋ࡚ᮇᚅࡉ
ࢀ࡚࠸ࡿࠋࡋ࠿ࡋࠊᚑ᮶ἲ࡛ᙧᡂࡉࢀࡓ SiO2 ⭷࡜ SiC ࡜ࡢ⏺㠃࡟࠾ࡅࡿḞ㝗ᐦᗘࡀ㧗࠸ࡓࡵࠊࢳࣕࢿࣝ⛣ືᗘࡣ SiO2/Si ࡟ẚ࡭ 1㹼2 ᱆ᑠࡉࡃࠊSiC ࢆ⏝࠸ࡓ MOS ࢹࣂ࢖ࢫࡢᐇ⏝໬ࢆ㜼ࡴ኱ࡁ࡞せᅉ࡜࡞ࡗ࡚࠸ࡿࠋ ᭱㏆ᡃࠎࡣࠊSiC(0001)ୖ࡟⛛ᗎ㓄ิᵓ㐀ࢆᣢࡘࢩࣜࢥࣥ㓟❅໬⭷㸦SiON ㉸ⷧ⭷㸧ࡀ࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗ࡍࡿࡇ࡜ࢆぢฟࡋࠊࡑࡢᵓ㐀ࢆప㏿㟁Ꮚᅇᢡ(LEED)ゎᯒ࡟ࡼࡾỴᐃࡋࡓ
㸦Fig. 1㸧[1]ࠋSiON/SiC(0001)⏺㠃࡟ࢲࣥࢢࣜࣥࢢ࣎ࣥࢻࡣ࡞ࡃࠊࣂࣝࢡ⤊➃ࡋࡓ SiC(0001)
㠃ࡢୖ࡟ࠊཎᏊ࡛ࣞ࣋ࣝᛴᓧ࡞⏺㠃ࢆᣢࡗ࡚࠸ࡿࠋࡲࡓࠊSiON ㉸ⷧ⭷ࡣࠊ❅໬ࢩࣜࢥSiࣥ༢ᒙ࡜ࡑࡢୖࡢ㓟໬ࢩࣜࢥࣥ༢ᒙ࠿ࡽᡂ

O

ࡿ஧㔜ᒙ⭷࡛࠶ࡿࠋ㉮ᰝࢺࣥࢿࣝศග(STS)ᐃ࡟ࡼࡿ࡜ࠊ᭱ୖᒙࡢ㓟໬ࢩࣜࢥࣥᒙࡣࠊ

N༢ᒙ࡛࠶ࡾ࡞ࡀࡽࣂࣝࢡࡢ SiO2 ࡢࣂࣥࢻࢠ
ࣕࢵࣉ࡜࡯ࡰྠࡌ ~ 9 eV ࡢ್ࢆᣢࡘࡇ࡜ࡀ

C

ぢฟࡉࢀࡓ[1]ࠋSiON ㉸ⷧ⭷ࡢ⌮ㄽⓗ◊✲ࡣࠊᡃࠎࡢㄽᩥฟ∧ᚋ᪩࠸᫬ᮇ࡟࠾ࡇ࡞ࢃࢀࠊ

Fig. 1 SiON/SiC(0001)ࡢᵓ㐀ࣔࢹࣝ㸦ഃ㠃ᅗ㸧ᡃࠎࡢ⤖ᯝࢆᨭᣢࡋࡓ [2]ࠋ SiON ㉸ⷧ⭷ࡢ⭷ཌࡣ㹼0.6 nm ࡛࠶ࡿࡢ࡛ࠊࢼࣀࢫࢣ࣮ࣝࢹࣂ࢖ࢫ࡬ࡢᒎ㛤ࡀᮇᚅࡉࢀࡿࠋ
ࡑࡢⅭ࡟ࡣࠊࣂࣥࢻࢠࣕࢵࣉᵓ㐀ࢆ᫂ࡽ࠿࡟ࡍࡿࡇ࡜ࡀ㔜せ࡛࠶ࡿࡢ࡛ࠊSAGA-LS BL12 ࡟࠾࠸࡚㌾ X ⥺྾཰(SXA)ཬࡧෆẆග㟁Ꮚศග(CLPES)ࠊSPring-8 ࡢ BL27SU ࡟࠾࠸࡚Ⓨගศ
ගἲ(SXE)ཬࡧ CLPES ࡟ࡼࡾ◊✲ࡋࡓࠋ N 1sࠊO 1s ࡢ SXA, SXE, CLPES ࠿ࡽࠊ❅໬ࢩࣜࢥࣥ༢ᒙࠊ㓟໬ࢩࣜࢥࣥ༢ᒙࡢྛ༢ᒙࡈ࡜ࡢࣂࣥࢻࢠࣕࢵࣉࠊࣂࣥࢻ࢜ࣇࢭࢵࢺࢆぢ✚ࡶࡿࡇ࡜ࡀฟ᮶ࡓࠋࣂࣥࢻศᩓࡢᐃࡣࠊKEK-PF ࡢ BL18A ࡛࠾ࡇ࡞ࡗࡓࠋ⌮ㄽ࡜ࡢⰋ࠸୍⮴ࡀᚓࡽࢀࡓ [2]ࠋtochihar@mm.kyushu-u.ac.jp[1] T. Shirasawa, K. Hayashi, S. Mizuno, S. Tanaka, K. Nakatsuji, F. Komori, H. Tochihara, Phys.
Rev. Lett. 98, 136105 (2007).
[2] P. Krüger, B. Baumeier, J. Pollmann, Phys. Rev. B 77, 085329 (2008).

㸫㸫

SiO2/SiC interface problem

JKIHFJKG>>:8'@RC,

%7$;</- (SiC)• :-/;-!6*3¬~3 eV­• «Y¨jh¬Si~10H­• «Cbh¬Si~5H­$ L)g6-12Bh

>B0:<+/&Xw 

SiO2/SiC«©~§ah• Si, C dangling bond
• Si suboxides• C clusters• C suboxides

SiO2
InterfaceSiC)6.8OhSi10-1~-2
SiC-MOS+/&_PZi`m¨/SiC©

Band gap of the topmost layer of the SiON

Crystalline SiON film on SiC(0001)
uP

Si¥
¥P(SiON)¡¡ o¦Atom-resolved STM images

3 x 3 Vv|£

Sample preparation

LEED 



Topm ost
SiO2 layer

Empty state image (Vs = 4.5 V)STM)

1340˚CN2
1 atm~15 min2~30 min

(0 1)
(1 0)

6
[1120]

RT
H2 etching

Nitridation
Oxidation

.*,+[1120]

8  8 nm2

40  40 nm2

Ei = 245 eV

5Å

Current (nA)

H2
1 atm

Protrusions correspond to Si atoms

Filled state image (Vs = -5.0 V)D¢¨[Wq|£z
Si oxidelayer• Q[948 =} kd©
• |£?(;#7;#5;-• SiC©L|o

Si nitride
layer[1120]

O

N

Si

4

8.7 eV

2
0
-2
-4
-6
-7 -5

[0001]
5Å

Consistent with the structure model
.-*2'%&31

C

Shirasawa et al., PRL 98, 136105 (2007)

Atomic-layer resolved band-gap structure

-3

-1

1

3

5

7

Sample bias voltage (V)The band gap of the mono-atomic
SiO2 layer is comparable to bulk
SiO2 of 9 eVProtrusions correspond to O atoms

m/SiC©

STS I-V characteristic

Reproduced by an ab-initio calculation
4
F. Devynck et al., Appl. Phys. Lett., 91, 061930 (2007)

XAS&XES on SiON/SiC(0001)
O K-edge

XAS: Soft X-ray absorption spectroscopy/X($  
XES: Soft X-ray emission spectroscopy/X(0  

N K-edgeXAS

XES^

Photoelectron
Analyzer
SampleMirrorXAS & XESJ¤r¨[n

Cbe
F

USGs

@SPring-8 BL27SU & SAGA-LS BL12Q[cM/;-!6*3|£
XAS
Cbe
PDOS
h

F¨[e

h

SPring-8 BL27SU
Si oxidelayer

XAS@SAGA-LS BL12 ?X7 ."#afbdZeC A( (TEY) E/E = 3000
\f^[C A( (AEY) E = 0.4 eV

Si nitride
layer

Kjh

XES

O 1s
N 1s

F¨[e
PDOS
h

Grating

SR

XES
O

N

Si

SPring-8 BL27SU ?X7 E_`f]ce
%N MCCDN&, E/E ~ 1300

C㸫㸫

CCD
Detector

O & N K-edge XAS at SAGA-LS BL12N 1s PESIntensity (arb. units)

Intensity (arb. units)





400

405

3

Intensity (arb. units)

Intensity (arb. units)

530

535

540

AES TEY

395

Incident photon energy (eV)O XES

540.1 eV539.1 eV405

410

408.2 eV407.2 eV530

*1 Shirasawa et al., PRL 98, 136105 (2007).
*2 Krüger et al PRB 77, 085329 (2008).

Band-gap profile of SiON film

N2p PDOS

537.1 eV525

8.3±0.8 eV

Binding energy below CBM (eV)h =433.2 eV538.1 eV

Emitted photon energy (eV)

380

384

388

392

396

400

Emitted photon energy (eV)K.8!<E\l F¨[ePDOSRt

3.0 eV

XES
TEY
AEY

8.3 eV0.2 eV

6.3±0.6 eV

1.9 eV®Xy/;-!6*3/8"I10

Binding energy below CBM (eV)"calculation

by x@Z]f54
SAGA-LS BL-12 (No. 080286N): 20 hrs
Spring-8 BL-27SU (No. 2007A2009): 48 hrs

CBM

6.3 eV

6.3 eVVBM

90.1 eV

3.0 eV0.1 eV
3.1 eV
CBM

Band-gap profile SiON/SiC(0001)
experimentAp =
STS{*1 : 8.7 eV
=Q{*2 : 8.9 eV

XES
TEY
AEY

N XES
Intensity (arb. units)

Intensity (arb. units)541.1 eV400

Incident photon energy (eV)h =554.2 eV542.1 eVO2p PDOSAEY
TEY

Intensity (arb. units)545

Band-gap profile SiON film

Intensity (arb. units)

540

CBMYX,S-O, -OOVQ/!+MPM

=

N K-edge XAS

Intensity (arb. units)

Intensity (arb. units)

AEY
TEY



545

Photon energy (eV)O K-edge XAS

3.1 eV-=4QWXC9

Krüger et al PRB 77, 085329 (2008).

O & N K-edge XES at Spring-8 BL27SU

535[11-20]

Photon energy (eV)Binding energy (eV)

520

[0001]

Sample410

O K-edge XAS

N 1s, O 1s %;#81<"N

Y*h

O 1s PES

530

Si-O-Si5
-O : <DQTU;-O : <DQ0E
395

Binding energy (eV)Polarization dependence of O K-edge XAS

N K-edge XAS

8.3 eVVBM
0.2 eV 1.99 eV#.!
_ª• CBMSiON?

T. Shirasawa Univ. Tokyo=

E. Kobayashi   SAGA-LS
T. Kinoshita   Spring-8 , JASRI  Spring-8 , JASRI 
T. MuroS. Tsuneyuki Univ. Tokyo=}• ©SiC bilayer!6*3g• SiON-SiCCBM2'*,
mSiO2/SiC TZ

12㸫㸫