寬能隙電子阻擋層改善有機太陽能電池效率

Efficiency Improvement in Organic Photovoltaic Cells by

Using Wide-Bandgap electron-Blocking Layer

D9670991

(OPV cell) ITO/CuPc (X nm)/C60 (Y nm)/BCP (10 nm)/Al (100 nm) CuPc C60 0.4 V 3.96 mA/cm2 63.1 % 1.00% 1. m-MTDATA 2.MeO-TPD

3.Ir(ppz)3 ITO/electron blocking

layer/CuPc(30 nm)/C60(40 nm) /BCP(10 nm)/Al(100 nm)

1. m-MTDATA(4 nm) 2.MeO-TPD (3 nm) 3.Ir(ppz)3(0.5 nm)

CuPc Pentacene Pentacene ITO/m-MTDATA/CuPc:(R%) Pentacene(30nm)/ C60(40nm)/BCP(10nm)/ Al(100nm) 5% : 7.74 mA/cm2 0.5 V 44.3 % 1.72 %

Abstract

In this thesis, we demonstrate a single heterojunction organic

photovoltaic (OPV) cell using wide-bandgap electron-blocking layer,

which can improve photocurrent absorption efficiency, balance carrier

mobility between acceptor and donor can affect the carrier collection

efficiency, and enhance the short-circuit current (JSC) , open-circuit

voltage (VOC)and the efficiency.

At first, we try to optimize the best structure in OPV cells whose layer in order as glass/ITO/CuPc (X nm)/C60 (Y nm)/BCP (10 nm)/Al

(100 nm), and then modulate the thickness of CuPc (electron donor layer)

X and C60 (electron acceptor layer) Y to get the highest power conversion

efficiency of this structure, which are 0.4 V of open-circuit voltage (VOC),

3.96 mA/cm2 of short-circuit current density (JSC), 63.1% of fill factor

(FF), and 1.00% of power conversion efficiency (PCE).

Secondly, We choose three wide-bandgap materials as electron-blocking layer, including ( 1 ) 4, 4', 4"- tris - ( 2 - methylphenyl

phenylamino ) triphenylamine ( m-MTDATA ) ( 2 ) MeO-TPD, and (3)

Ir(ppz)3, and try to modulate the thickness of electron-blocking layer to

optimize the best properties, including photo-current density and open

circuit voltage. The structure can reduced electron - hole recombination

of OPV cell is ITO / electron-blocking layer / CuPc(X nm) / C60 (Y nm)/

BCP(10nm) / Al(100nm). The optimal thickness is m-MTDATA (4 nm);

Finally, we choose the best performance material, m-MTDATA, as an electron-blocking layer. In additional, we doping pentacene into

electron donor layer to enhance the mobility of CuPc. By the increasing

of concentration on pentacene, we also find short-circuit current density

(JSC ) and power conversion efficiency (PCE) were increased

dramatically. This structure whose layer in order as ITO/CuPc:(R%)

Pentacene (30nm)/C60 (40nm)/ BCP (10nm)/ Al (100nm). We tune

concentration of Pentacene around 5% in CuPc to acquire excellent

characteristics of OPV cell, including: 7.74 mA/cm2 of short-circuit

current, 0.5 V of open-circuit voltage, 44.3% of fill factor, and 1.72% of

efficiency.

………..………...i ……… ..iii ………...………...vi ………... ... 1 1-1 .……… ………… 1 1-2 ……….………. 4 ………... ..6 2-1 ……… ..6 2-2 ………...7 2-3 ………....8 2-3-1 (VOC) ………...8 2-3-2 (ISC)………...………...8 2-3-3 (PCE)………...9 2-3-4 (FF) ………...…10 2-4 ………...10 2-5 ………..……… 12

2-5-1 ………....…………...………13 2-5-2 (VOC) ……….13 2-5-3 (ISC) ………...……14 2-5-4 (PCE) ………15 2-5-5 (FF) ………...15 2-6 ………..………...15 2-6-1 (PCE) ………...15 2-6-2 ………..……….16 2-6-3 (AFM) ………...16 ………..……….….17 3-1 ………...………17 3-2 ………...………18 3-3 ………...………....18 3-4 Al ………18 ………...……...…....20 4-1 .……….………... 20 4-2 CuPc (X nm) ………..21 4-3 C60 (Y nm) ………...………22 4-4 …..………...23

4-4-1 m-MTDATA (A nm)………..….24 4-4-2 MeO-TPD (B nm) ………25 4-4-3 Ir(ppz)3 (C nm) ………...………..26 4-5 CuPc Pentacene ………27 ………...29 …………...………..30

4-1 ………..20 4-2 CuPc ……….22 4-3 C60 ………23 4-4 m-MTDATA ………...24 4-5 MeO-TPD …………..26 4-6 Ir(ppz)3 ……….27 4-7 m-MTDATA RMS………...28 4-8 CuPc pentacene …28

.1-1 (a) (b)BHJ (c) P-I-N ………...34 .1-2 Air Mass(AM) ………..35 .2-1 ………..36 .2-2 ………...…….36 .2-3 ………..37 .2-4 ………..37 .2-5 ………..38 .3-1 ………..39 .4-1 (ITO/CuPc/C60/BCP/Al) …………..40 .4-2 ………41 .4-3 ………42

.4-4 (ITO/ Electron-Blocking Layer/CuPc /C60/BCP/Al) ………..43

.4-5 (ITO/m-MTDATA/CuPc: Pentacene (R%)/C60/BCP/Al) ……….44

.4-6 ITO /CuPc(20 nm)/C60(50 nm)/BCP(10 nm)/Al(100 nm)...45

.4-7 ITO /CuPc(25 nm)/C60(40 nm)/BCP(10 nm)/Al(100 nm)...46

.4-9 ITO /CuPc(35 nm)/C60(40 nm)/BCP(10 nm)/Al(100 nm)...48

.4-10 ITO /CuPc(30 nm)/C60(30 nm)/BCP(10 nm)/Al(100 nm)...49

.4-11 ITO /CuPc(30 nm)/C60(50 nm)/BCP(10 nm)/Al(100 nm)...50

.4-12 ………..51

.4-13 (ITO/m-MTDATA/CuPc/C60/BCP

/Al)………...……….52

.4-14 ITO /m-MTDATA(7.5 nm)/CuPc(30 nm)/C60(40 nm)/BCP

(10 nm)/Al(100 nm) ………53

.4-15 ITO /m-MTDATA(4 nm)/CuPc(30 nm)/C60(40 nm)/BCP

(10 nm)/Al(100 nm) ………54

.4-16 (ITO/MeO-TPD/CuPc/C60/BCP

/Al) ……….55

.4-17 ITO /MeO-TPD(7.5 nm)/CuPc(30 nm)/C60(40 nm)/BCP

(10 nm)/Al(100 nm) ………56

.4-18 ITO /MeO-TPD(3 nm)/CuPc(30 nm)/C60(40 nm)/BCP

(10 nm)/Al(100 nm) ………57

.4-19 (ITO/MeO-TPD/CuPc/C60/BCP

/Al) ………..……….58

.4-20 ITO /Ir(ppz)3(7.5 nm)/CuPc(30 nm)/C60(40 nm)/BCP

(10 nm)/Al(100 nm) ………...………59

.4-21 ITO /Ir(ppz)3(0.5 nm)/CuPc(30 nm)/C60(40 nm)/BCP

(10 nm)/Al(100 nm) ………60

.4-24 m-MTDATA (3 nm) ………..62

.4-25 ITO /m-MTDATA(4 nm)/CuPc:(R%)pentacene (30 nm)/

C60(40 nm)/BCP(10 nm)/Al(100 nm) ………..63

.4-26 ITO/m-MTDATA(4 nm)/CuPc:(3%)pentacene(30 nm)/

C60(40 nm)/BCP(10 nm)/Al(100 nm) ………..64

.4-27 ITO /m-MTDATA(4 nm)/CuPc:(5%)pentacene (30 nm)/

C60(40 nm)/BCP(10 nm)/Al(100 nm) ………..65

.4-28 ITO /m-MTDATA(4 nm)/CuPc:(7%)pentacene (30 nm)/

C60(40 nm)/BCP(10 nm)/Al(100 nm) ………..66

.5-1 (ITO /m-MTDATA(4 nm)/ CuPc :

(5%) pentacene (30 nm)/C60(40 nm) /BCP(10 nm)/ Al

1973 (OPV cell)

1-1

OPV cell PCE 1986 C. W. Tang OPV cell / CuPc

(perylene-derivatives) [1]

/ OPV cell

0.95 OPV cell

2000 S. R. Forrest OPV cell

[2] 3,4,9,10 -perylenetetracarboxylic bisbenzimidazole PTCBI 2.4 2001 P. Peumans S. R. Forrest C60 PTCBI C60 (77 ± 10 Å) PTCBI (30 ± 3Å) C60 3,4- /

4-(polymer poly (3,4-ethylenedioxythiophene): poly

(styrenesulfonate)) PEDOT PSS ITO

3.6 [3] 2004 S. R. Forrest OPV cell

4.2 [4] [5]

Voc 5.7

CuPc OPV cell 10nm[6]

bulk herero-junction BHJ JSC 2003 Sullivan et al. CuPc C60 1:1 BHJ (CuPc C60) 1-1 a-b [7] BHJ JSC( 4.6 mA/cm 2 ) 3.4 mA/cm2 BHJ (0.87 ) (0.75 ) (BHJ ) p-i-n [8] p-i-n CuPc C60 CuPc C60 0.75 0.87 BHJ 1.17 p-i-n 1 sun (100 mW/cm 2 ) (VOC) (JSC)

[8] [9] [10] [11] [12] - [14]

1-2

OPV cell HBL -PCE [15] SnPc / C60 OPV cell - OPV cell

-OPV cell Glass/ITO / CuPc/C60/BCP/Al CuPc

ITO C60 2,9

- 4 ,7 – - 1 10- (2,9-dimethyl-4,7-diphenyl-1,10-

phenanthroline) BCP HBL

MeO- TPD Ir ppz 3 JSC)

(VOC) FF (PCE)

pentacene ITO /m- MTDATA /

CuPc/C60/BCP/Al CuPc

OPV cell pentacene

2-1

80

W/m2

(air mass) AM AM0 90°

1353 W/m2 5800K

AM1 ( 90°)

925 W/m2 AM1.5 48°

844 W/m2 AM1.5

2-2

20 30

20

Chapin, Fuller Pearson

PCE 6 sc- Si sc -Si sc-Si p p p-n p-n (S.C.R.) p-n p-n p-n (1)

( 1) qV nkT S I = I e − (1) IS k q η T KT/ q 0.026V p-n p-n p n p n n p (2) 2-1 ( 1) qV kT S L I = I e − −I (2)

2-3

2-3-1

(V

OC

)

p-n p n p n VOC I 2 3 (3)

2-3-2

I

SC N P

n p = 0 ISC -IL

2-3-3

(PCE)

(4) ( 1) qV kT S L P = IV = I V e − −I V ₍₄₎ 4 Pmax dP/dV = 0 4 Pmax 5 6 (5) (6)

7 8 JSC VOC VPMAX IPMAX 2 - 2

100(mW/cm2) 25 (mW/cm2) (7) (8)

2-3-4

(FF)

Rsa Rsh Rsa p-n -Rsh Rsh Rsa Rsh 2-3 (2) (9) Fill Factor(FF) Rsa Rsh 10 (9) (10)

2-4

OPV cell 2.4

1.

HOMO LUMO 100nm (60 90 )

2.

10 nm[16]

3.

/

BHJ

/

4.

ITO (polyethylene

dioxythiophene doped with polystyrene-sulfonic acid) PEDOT PSS

LiF

2-5

OPV

cell VOC ISC FF IPCE

2-5-1

OPV cell Rsa Rsh (n) V = ± 1 V Rsh [17] [18] (11) (12) V > 0.1V (13) OPV cell (14) I-V (14) (15) Rsa =Rs×A

(11)

(12)

(13)

(14)

(15)

2-5-2

(V

OC

)

OPV cell VOC OPV cell / VOC LOMO [19] [20]

2-5-3

(I

SC

)

OPV cell

- OPV cell

ISC

OPV cell IQE 16

η

IQE

=

η η η η

A ED CT CC (16) ηIQE ;ηA ηED ηCT ηCC d ηA ηED ηCT ηCC (17)-(18)

1

ad A

e

η

_{= −}

− (17) / _D d L ED

e

η

₌

− (18) OPV cell (LD) ηA ηED ηIQE

OPV cell PCE

2-5-4

(PCE)

OPV cell PCE PV cell

PMAX (5) (6)

(7) PCE (8)

2-5-5

(FF)

OPV cell FF PV cell

(10) 2 - 3 FF Rsa Rsh FF Rsa Rsh OPV cell Rsa Rsh

2-6

2-6-1

(PCE)

OPV cell (I-V) IV IV PCE

2-6-2

/ (V- 670) 190 2700nm

2-6-3

(AFM)

AFM P7LS 2-5 19

(19) σ r ε r r

(IPA) (1) (pre-clean) (2) (3) (4)

3-1

OPV cell IPA 5 5 5 5 100

3-2

ITO 3-1 ITO 60 40 ITO 37% 38 3:7 ITO ITO ITO

3-3

ITO ITO ITO 15 ITO

3-4

Al

3 × 10-6 Torr 0.5-2Å 3-1 m-MTDATA MeO-TPD Ir ppz 3

CuPc C60 BCP

4-1

OPV cell Glass/ITO /CuPc(Xnm)/ C60(Ynm)/BCP(10nm)/ (100nm) 4-1 ITO CuPc C60 BCP (m- MTDATA MeO- TPD Ir ppz 3) CuPc C60 4-2 C60 450 nm CuPc 620 nm 4-3 4-1

Organic Material LUMO/ HOMO (eV)

Mobility (cm2/V s)

Exciton diffusion length (nm) CuPc 3.5/5.2 7.0 × 10-3 15 C60 4.5/6.2 5.0 × 10-1 40 BCP 3.5/7.0 2.0 × 10-3 <10 4-1 BCP 10nm 100nm CuPc C60 ITO

/CuPc(Xnm)/ C60(Ynm)/BCP(10nm)/ (100nm) 4-1

ITO CuPc

-1 4 4' 4“ – - 2 - ( 2 - methylphenyl

phenylamino ) (triphenylamine) m- MTDATA 2 MeO- TPD

3 Ir ppz 3 ITO / /CuPc(Xnm)/ C60(Ynm)/BCP(10nm)/ (100nm) 4-4 OPV cell Pentacene CuPc CuPc

ITO /m- MTDATA /CuPc (R )Pentacene(Xnm)/

C60(Ynm)/BCP(10nm)/ (100nm) 4-5

4-2 CuPc

(X nm)

CuPc 20nm C60 50nm [21] [22] Keithley 2400 100mW/cm2 - 1V 1V VOC 0.4 V JSC 3.07 mA/cm 2 FF 55.2 PCE 0.68 4-6

CuPc 25nm VOC 0.4 V JSC 3.73 mA/cm 2 FF 59.2 PCE 0.88 4-7 CuPc 30nm JSC 3.96 mA/cm2 FF 63.1 VOC 0.4V PCE 40nm 1.00 4-8 CuPc 35nm JSC 4.03mA/cm2 VOC 0.4 V FF 57.6 PCE 0.93 4-9 CuPc 30nm 4-2 CuPc (nm)/C60 (40 nm) VOC (V) JSC (mA/cm2) FF (%) η (%) 25 0.4 3.73 59.2 0.88 30 0.4 3.96 63.1 1.00 35 0.4 4.03 57.6 0.93 4-2 CuPc

4-3 C

60

(Y nm)

4-2 CuPc 30nm ITO /CuPc(30nm)/ C60 (Ynm)/BCP(10nm)/ (100nm) CuPc 30nm C60 40nm 4-2 JSC

4.03mA/cm2 3.96mA/cm2 VOC 0.4V FF 63.1 PCE 1.00 4-8 C60 30nm JSC 2.63 mA/cm 2 FF 55.9 VOC 0.4V PCE 0.59 4-10 C60 50nm C60 JSC 3.39mA/cm 2 FF 57.1 VOC 0.4 V PCE 0.76 4-11 CuPc 30nm C60 40nm 4-3 ITO/CuPc(30nm)/C60(40nm)/BCP(10nm)/ (100nm) CuPc (30nm)/ C60 (nm) VOC (V) JSC (mA/cm2) FF (%) η (%) 30 0.4 2.63 55.9 0.59 40 0.4 3.96 63.1 1.00 50 0.4 3.39 57.1 0.76 4-3 C60

4-4

ITO CuPc -M - -MTDATA [23]

ITO / /CuPc(30nm)/ C60(40nm)/BCP(10nm)/ (100nm) 4- 4

4-4-1 m-MTDATA

(A nm)

m- MTDATA -7.5nm ITO/m- MTDATA(Anm /CuPc(30nm)/ C60(40nm)/BCP(10nm)/ (100nm) 4-13 7.5nm VOC 0.5V JSC 4.00 mA/cm 2 FF 25.0 PCE 0.50 4- 14 m-MTDATA (5 nm 3nm) 3nm m-MTDATA (4 nm 3.5nm) m–MTDATA 4nm VOC 0.5V JSC 7.26 mA/cm 2 FF 43.1 PCE 1.56 4-15 4-4 m-MTDATA (nm) VOC (V) JSC (mA/cm2) FF (%) η (%) 7.5 0.5 4.00 25.0 0.50 5 0.5 6.19 41.1 1.27 4 0.5 7.26 43.1 1.56 3.5 0.4 6.68 49.6 1.33 3 0.4 5.93 54.5 1.29 4-4 m-MTDATA

4-4-2 MeO-TPD

(B nm)

MeO-TPD LUMO HOMO m– MTDATA

LUMO/HOMO 1.9V/5.1V m- MTDATA 4-4-1 7.5nm ITO /MeO-TPD(B nm)/CuPc(30nm)/ C60(40nm)/BCP(10nm)/ (100nm) 4-16 7.5nm VOC 0.5V JSC 4.10 mA/cm2 FF 25.9 PCE 0.53 4-17 MeO-TPD (5nm 4nm 3nm 2.5nm) 3nm VOC 0.4V JSC 4.61 mA/cm 2 FF 61.0 PCE 1.12 4 - 18 FF M – MTDATA 43.1 61.0 VOC 0.4 V JSC 4.61mA/cm 2 4-5

MeO-TPD thickness (nm) VOC (V) JSC (mA/cm2) FF (%) η (%) 7.5 0.5 4.10 25.9 0.53 5 0.4 4.36 59.0 1.03 4 0.4 4.24 61.1 1.04 3 0.4 4.61 61.0 1.12 2.5 0.4 3.95 58.9 0.93 4-5 MeO-TPD

4-4-3 Ir(ppz)

3

(C nm)

Ir(ppz)3 1.6V LUMO m-MTDATA 0.3 5.0V HOMO ITO 4-4-1 7.5nm ITO /Ir(ppz)3(C nm)/CuPc(30nm)/ C60(40nm /BCP(10nm / (100nm 4 - 19 7.5nm VOC 0.5V JSC 2.52 mA/cm2 FF 54.9 PCE 0.55 4-20 Ir(ppz)3 5nm 4nm 1nm 0.5nm 0.5nm VOC 0.4 V JSC 3.81 mA/cm2 FF 59.8 PCE 0.91 4–21

m–MTDATA FF 43.1 59.8 VOC 0.4 V JSC 7.26 mA/cm 2 3.81 mA/cm2 4-6 Ir(ppz)3 (nm) VOC (V) JSC (mA/cm2) FF (%) η (%) 7.5 0.5 2.52 54.9 0.55 5 0.4 2.96 60.6 0.72 4 0.4 3.05 62.3 0.76 1 0.4 3.39 63.8 0.87 0.5 0.4 3.81 59.8 0.91 4-6 Ir(ppz)3

4-5

CuPc

Pentacene

4-4 m-MTDATA m - MTDATA 4nm VOC 0.5V JSC 7.26 mA/cm 2 FF 43.1 PCE 1.56 m-MTDATA JSC 7.26 mA/cm2 FF 4-22 4-24 4-7 RMS Pentacene = 1.5 cm2/V-s CuPc

wt. 3 5 7 Pentacene CuPc

m-MTDATA ITO /m- MTDATA 4nm /CuPc

R Pentacene 30nm / C60 40nm /BCP 10nm / 100nm 4-25 wt.3 VOC 0.5V JSC 6.26 mA/cm2 FF 46.6 PCE 1.46 4-26 wt.5 VOC 0.5V JSC 7.74 mA/cm 2 FF 44.3 PCE 1.72 4-27 wt. 7 VOC 0.5V JSC 6.66 mA/cm 2 FF 49.3

PCE 1.31 4-28 OPV cell

4-8

m-MTDATA (nm) Surface roughness (nm) Surface RMS (nm) 7.5 2.116 2.768 4 2.931 3.723 3 3.008 3.709 4-7m-MTDATA RMS

Pentacene concentration (wt. %) VOC (V) JSC (mA/cm2) FF (%) η (%)

0 0.5 7.26 43.1 1.56

3 0.5 6.26 46.6 1.46

5 0.5 7.74 44.3 1.72

7 0.4 6.66 49.3 1.31

OPV cell

m-MTDATA MeO- TPD Ir ppz 3 ITO Pentacene

CuPc m-MTDATA m-MTDATA 4nm VOC 0.5V JSC7.26 mA/cm 2 FF 43.1 PCE 1.56 Pentacene CuPc - Wt.5 pantacene

CuPc OPV cell 1.56 1.72

ITO /m- MTDATA 4nm /CuPc 5 Pentacene 30nm / C60

[1] C. W. Tang, “Two-layer organic photovoltaic cell,” Appl. Phys. Lett.

Vol. 48, p. 83 (1986).

[2] P. Peumans, V. Bulovi and S. R. Forrest, “Efficient photon harvesting

at high optical intensities in ultrathin organic double-heterostructure

photovoltaic diodes,” Appl. Phys. Lett., Vol. 76, p. 2650 (2000).

[3] P. Peumans and S. R. Forrest, “Very-high-efficiency

double-heterostructure copper phthalocyanine/C60 photovoltaic

cells,” Appl. Phys. Lett., Vol. 79, p. 126 (2001).

[4] J. Xue, S. Uchida, B. P. Rand and S.R. Forrest, “4.2% efficient

organic photovoltaic cells with low series resistances,” Appl. Phys.

Lett., Vol. 84, p. 3013 (2004).

[5] J. Xue, S. Uchida, B. P. Rand and S. R. Forrest, “Asymmetric tandem

organic photovoltaic cells with hybrid planar-mixer molecular

heterojunctions,” Appl. Phys. Lett., Vol. 85, p. 5757 (2005).

[6] T. Osasa, Y. Matsui, T. Matsumura, and M. Matsumura,

“Determination of photo-active region in organic thin film solar cells

with an organic heterojunction,” Sol. Energy Mater. Sol. Cells, Vol.

90, p. 3136 (2006).

[7] P. Sullivan, S. Heutz, S. M. Schultes, and T.S. Jones, “Influence of

codeposition on the performance of CuPc-C60 heterojunction

photovoltaic devices,” Appl. Phys. Lett., Vol. 84, p. 1210 (2004).

[8] Bo Yu, Feng Zhu, Haibo Wang, Gao Li, and Donghang Yan,

“All-organic tunnel junctions as connecting units in tandem organic

[9] J. Xue, S. Uchida, B. P. Rand, and S. R. Forrest, “Asymmetric

tandem organic photovoltaic cells with hybrid planar-mixed

molecular heterojunctions,” Appl. Phys. Lett., Vol. 85, p. 5757

(2004).

[10]I. A. Levitsky, W. B. Euler, N. Tokranova, B. Xu, and J. Castracane,

“Hybrid solar cells based on porous Si and copper phthalocyanine

derivatives,” Appl. Phys. Lett., Vol. 85, p. 6245 (2004).

[11]M. Y. Chan, S. L. Lai, M. K. Fung, C. S. Lee, and S. T. Lee,

“Doping-induced efficiency enhancement in organic photovoltaic

devices,” Appl. Phys. Lett., Vol. 90, p. 023504 (2007).

[12]P. Peumans and S. R. Forrest, “Very-high-efficiency

double-heterostructure copper phthalocyanine/C60 photovoltaic

cells,” Appl. Phys. Lett., Vol. 79, p. 126 (2001).

[13]I. Yoo, M. Lee, C. Lee, D. W. Kim, I. S. Moon, and D. H. Hwang,

“The effect of a buffer layer on the photovoltaic properties of solar

cells with P3OT:fullerene composites,” Synt. Meta., Vol. 153, p. 97

(2005).

[14]V. Shrotriya, E. H. E. Wu, G. Li, Y. Yao, and Y. Yang, “Efficient light

harvesting in multiple-device stacked structure for polymer solar

cells,” Appl. Phys. Lett., Vol. 88, p. 064104 (2006).

[15]Ning Li, Brian E. Lassiter, Richard R. Lunt, Guodan Wei, and

Stephen R. Forrest, “Open circuit voltage enhancement due to

reduced dark current in small molecule photovoltaic cells,” Appl.

Phys. Lett., Vol. 94, p. 023307 (2009).

(2000).

[17]J. Xue, S. Uchida, B. P. Rand, and S. R. Forrest, “4.2% efficient

organic photovoltaic cells with low series resistances,” Appl. Phys.

Lett., Vol. 84, p. 3013 (2004).

[18]V. D. Mihailetchi, P. W. M. Blom, J. C. Hummelen, and M. T.

Rispens, “Cathode dependence of the open-circuit voltage of

polymer:fullerene bulk heterojunction solar cells,” J. Appl. Phys., Vol.

94, p. 6849 (2003).

[19]C. J. Brabec, A. Cravino, D. Meissner, N. S. Sariciftci, T. Fromherz,

M. T. Rispens, L. Sanchez, J. C. Hummelen, “Origin of the Open

Circuit Voltage of Plastic Solar Cells,” Adv. Fun. Mater., Vol. 11, p.

374 (2001).

[20]J. C. Bernède, Y. Berredjem, L. Cattin, and M. Morsli,

“Improvement of organic solar cell performances using a zinc oxide

anode coated by an ultrathin metallic layer,” Appl. Phys. Lett., Vol. 92,

p. 083304 (2008).

[21]I. C. Chen, “Improved Efficiency of p-n Junction Organic

Photovoltaic Cell,” NCKU (2008).

[22]K. H. Hsiao, “Study of Silver Oxide Anode of Single

Donor-Acceptor Heterojunction Photovoltaic Cell,” NCKU (2009).

[23]L.L. Chen, W.L. Li, H.Z. Wei, B. Chu, B. Li, “ Organic ultraviolet

photovoltaic diodes based on copper phthalocyanine as an electron

acceptor,” Sol. Energy Mater. Sol. Cells, Vol. 90, p. 1788 (2006).

[24]J. Drechsel, B. Mannig, F. Kozlowski, D. Gebeyehu, A. Werner, M.

on single or multiple PIN structures,” Thin Solid Films, 451-452, p.

515 (2004).

[25]Hiroshi Kanno, Yiru Sun, and Stephen R. Forrest, “High-efficiency

top-emission white-light-emitting organic electrophosphorescent

devices,” Appl. Phys. Lett., Vol. 86, p. 263502 (2005).

[26]Wei-Bing Chen, Hai-Feng Xiang, Zong-Xiang Xu, Bei-Ping Yan,

“Improving efficiency of organic photovoltaic cells with pentacene

Figure

. 1-1

(a) (b) BHJ

(c) P-I-N

(From Appl. Phys. Lett., Vol. 84, p.

48°°°°

48°°°°

. 2-1

0.0 0.1 0.2 0.3 0.4 0.5 -3 -2 -1 0 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V P_MAX V_MAX J_MAX J_SC V_OC ( J．．．．V )_MAX 0.0 0.1 0.2 0.3 0.4 0.5 -3 -2 -1 0 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V P_MAX V_MAX J_MAX J_SC V_OC ( J．．．．V )_MAX P_MAX V_MAX J_MAX J_SC V_OC ( J．．．．V )_MAX

. 2-2

. 2-3

Anode

Cathode

hν

ν

ν

ν

E

Acceptor

Donor

Anode

Cathode

hν

ν

ν

ν

E

Acceptor

Donor

. 2-4

Glass

ITO 145 nm

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

Glass

ITO 145 nm

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

7.0 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV

5.2 eV

6.2 eV

4.5 eV

4.2 eV

3.5 eV

3.5 eV

7.0 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV

5.2 eV

6.2 eV

4.5 eV

4.2 eV

3.5 eV

3.5 eV

. 4-1

(ITO/CuPc/C60/BCP/Al)

400 500 600 700 800 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 A b s o rb a n c e ( a .u .) Wavelength (nm) CuPc C₆₀

. 4-2

Glass

ITO 145 nm

Electron Blocking Layer

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

Glass

ITO 145 nm

Electron Blocking Layer

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

7.0 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 3.5eV

E

le

ct

ro

n

B

lo

ck

in

g

L

a

y

er

7.0 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 3.5eV

E

le

ct

ro

n

B

lo

ck

in

g

L

a

y

er

. 4-4

(ITO/ Electron-Blocking Layer/CuPc /C60/BCP/Al)

Glass

ITO 145nm

m-MTDATA (A nm)

CuPc :(R%)Pentacene

C

₆₀

BCP 10 nm

Al 100 nm

Glass

ITO 145nm

m-MTDATA (A nm)

CuPc :(R%)Pentacene

C

₆₀

BCP 10 nm

Al 100 nm

7.0 eV

1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV

5.2 eV

6.2 eV

4.5eV

4.2 eV

3.5 eV

5.1 eV

3.5 eV

m

-MT

D

A

T

A

4.9 eV

3.0 eV

Pentacene

7.0 eV

1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV

5.2 eV

6.2 eV

4.5eV

4.2 eV

3.5 eV

5.1 eV

3.5 eV

m

-MT

D

A

T

A

4.9 eV

3.0 eV

Pentacene

. 4-5

(ITO/m-MTDATA/CuPc: Pentacene (R%)/C60/BCP/Al)

-1.0 -0.5 0.0 0.5 1.0 0 10 20 30 40 50 60 46 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(20nm)/C₆₀(50nm) 0.0069 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -4 -3 -2 -1 0 1 J_MAX = 2.27 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(20nm)/C₆₀(50nm) J_SC = 3.08 mA/cm2 ηηηη = 0.68 % % % % FF = 55.3 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-6 ITO/CuPc(20 nm)/C

60

(50 nm)/BCP(10 nm)/Al

(100nm)

-1.0 -0.5 0.0 0.5 1.0 0 10 20 30 40 50 60 70 80 60.8 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(25nm)/C₆₀(40nm) 0.0057 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -5 -4 -3 -2 -1 0 1 J_MAX = 2.94 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(25 nm)/C₆₀(40nm) J_SC = 3.73 mA/cm2 ηηηη = 0.88 % % % % FF = 59.2 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-7 ITO/CuPc(25 nm)/C

60

(40 nm)/BCP(10 nm)/Al

(100nm)

-1.0 -0.5 0.0 0.5 1.0 0 10 20 30 40 50 33.9 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(30nm)/C₆₀(40nm) 0.0559 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -5 -4 -3 -2 -1 0 1 J_MAX = 3.34 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(30nm)/C₆₀(40nm) J_SC = 3.96 mA/cm2 ηηηη = 1.00 % % % % FF = 63.1 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-8 ITO/CuPc(30 nm)/C

60

(40 nm)/BCP(10 nm)/Al

(100nm)

-1.0 -0.5 0.0 0.5 1.0 -10 0 10 20 30 40 50 60 70 80 66.6 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(35nm)/C₆₀(40nm) 0.0135 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -5 -4 -3 -2 -1 0 1 J_MAX = 3.10 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(35nm)/C₆₀(40nm) J_SC = 4.03 mA/cm2 ηηηη = 0.93 % % % % FF = 57.6 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-9 ITO/CuPc(35 nm)/C

60

(40 nm)/BCP(10 nm)/Al

(100nm)

-1.0 -0.5 0.0 0.5 1.0 -10 0 10 20 30 40 50 60 70 80 90 100 88.8 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(30nm)/C₆₀(30nm) 0.0134 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -4 -3 -2 -1 0 1 J_MAX = 1.96 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(30nm)/C₆₀(30nm) J_SC = 2.63 mA/cm2 ηηηη = 0.59 % % % % FF = 55.9 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-10 ITO/CuPc(30 nm)/C

60

(30 nm)/BCP(10 nm)/Al

(100nm)

-1.0 -0.5 0.0 0.5 1.0 -10 0 10 20 30 40 50 60 70 80 90 78.6 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(30nm)/C₆₀(50nm) 0.0102 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -4 -3 -2 -1 0 1 J_MAX = 2.54 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V CuPc(30nm)/C₆₀(50nm) J_SC = 3.39 mA/cm2 ηηηη = 0.76 % % % % FF = 57.1 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-11 ITO/CuPc(30 nm)/C

60

(50 nm)/BCP(10 nm)/Al

(100nm)

100 200 300 400 500 600 700 800 900 1000 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 A b s o rb a n c e ( a .u .) Wavelength (nm) m-MTDATA MeO-TPD Ir(ppz)₃

. 4-12

Glass

ITO 145nm

m-MTDATA (A nm)

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

Glass

ITO 145nm

m-MTDATA (A nm)

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

7.0 eV 1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 5.1 eV 3.5eV

m

-M

T

D

A

T

A

7.0 eV 1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 5.1 eV 3.5eV

m

-M

T

D

A

T

A

. 4-13

(ITO/m-MTDATA/CuPc/C

60

/BCP/Al)

-1.0 -0.5 0.0 0.5 1.0 -1 0 1 2 3 4 5 6 7 8 7.1 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V m-MTDATA(7.5nm) 0.0126 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -5 -4 -3 -2 -1 0 1 J_MAX = 2.50 mA/cm2 V_MAX = 0.2 V V_OC = 0.5V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V m-MTDATA(7.5nm) J_SC = 4.00 mA/cm2 ηηηη = 0.50 % % % % FF = 25.0 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-14 ITO/m-MTDATA(7.5 nm)/CuPc(30 nm)/C

60

(40

nm)/BCP(10 nm)/Al(100nm)

-1.0 -0.5 0.0 0.5 1.0 0 10 20 30 40 50 60 70 80 67.8 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V m-MTDATA(4nm) 0.0262 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 J_MAX = 5.21 mA/cm2 V_MAX = 0.3 V V_OC = 0.5V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V m-MTDATA(4nm) J_SC = 7.26 mA/cm2 ηηηη = 1.56 % % % % FF = 43.1 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-15 ITO/m-MTDATA(4 nm)/CuPc(30 nm)/C

60

(40

nm)/BCP(10 nm)/Al(100nm)

Glass

ITO 145 nm

MeO-TPD (B nm)

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

Glass

ITO 145 nm

MeO-TPD (B nm)

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

7.0 eV 1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 5.1 eV 3.5eV

M

eO

-T

P

D

7.0 eV 1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 5.1 eV 3.5eV

M

eO

-T

P

D

. 4-16

(ITO/MeO-TPD/CuPc/C

60

/BCP/Al)

-1.0 -0.5 0.0 0.5 1.0 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 12.8 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V MeO-TPD(7.5nm) 0.0040 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -5 -4 -3 -2 -1 0 1 J_MAX = 2.66 mA/cm2 V_MAX = 0.2 V V_OC = 0.5V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V MeO-TPD(7.5nm) J_SC = 4.10 mA/cm2 ηηηη = 0.53 % % % % FF = 25.9 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-17 ITO/MeO-TPD(7.5 nm)/CuPc(30 nm)/C

60

(40

nm)/BCP(10 nm)/Al(100nm)

-1.0 -0.5 0.0 0.5 1.0 -10 0 10 20 30 40 50 60 70 80 90 77.8 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V MeO-TPD(3nm) 0.0053 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -6 -5 -4 -3 -2 -1 0 1 J_MAX = 3.75 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V MeO-TPD(3nm) J_SC = 4.61 mA/cm2 ηηηη = 1.12 % % % % FF = 60.1 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-18 ITO/MeO-TPD(3 nm)/CuPc(30 nm)/C

60

(40

nm)/BCP(10 nm)/Al(100nm)

Glass

ITO 145 nm

Ir(ppz)

₃

(C nm)

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

Glass

ITO 145 nm

Ir(ppz)

₃

(C nm)

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

7.0 eV 1.6 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 5.0 eV 3.5eV

Ir

(

p

p

z

)

3 7.0 eV 1.6 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 5.0 eV 3.5eV

Ir

(

p

p

z

)

3

. 4-19

(ITO/Ir(ppz)

3

/CuPc/C

60

/BCP

/Al)

-1.0 -0.5 0.0 0.5 1.0 -10 0 10 20 30 40 50 60 70 80 90 _{82.4 mA/cm}2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Ir(ppz)₃(7.5nm) 0.0052 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -4 -3 -2 -1 0 1 J_MAX = 1.84 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Ir(ppz) 3(7.5nm) J_SC = 2.52 mA/cm2 ηηηη = 0.55 % % % % FF = 54.9 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-20 ITO/Ir(ppz)

3

(7.5 nm)/CuPc(30 nm)/C

60

(40

nm)/BCP(10 nm)/Al(100nm)

-1.0 -0.5 0.0 0.5 1.0 -10 0 10 20 30 40 50 60 70 80 90 _{81.9 mA/cm}2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Ir(ppz)₃(0.5nm) 0.0048 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -5 -4 -3 -2 -1 0 1 J_MAX = 3.04 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Ir(ppz)₃(0.5nm) J_SC = 3.81 mA/cm2 ηηηη = 0.91 % % % % FF = 59.8 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-21 ITO/Ir(ppz)

3

(0.5 nm)/CuPc(30 nm)/C

60

(40

nm)/BCP(10 nm)/Al(100nm)

. 4-22

m-MTDATA (7.5 nm)

Glass

ITO 145nm

m-MTDATA (4 nm)

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

Glass

ITO 145nm

m-MTDATA (4 nm)

CuPc

C

₆₀

BCP 10 nm

Al 100 nm

7.0 eV

1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV

5.2 eV

6.2 eV

4.5eV

4.2 eV

3.5 eV

5.1 eV

3.5 eV

m

-M

T

D

A

T

A

4.9 eV

3.0 eV

Pentacene

7.0 eV

1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV

5.2 eV

6.2 eV

4.5eV

4.2 eV

3.5 eV

5.1 eV

3.5 eV

m

-M

T

D

A

T

A

4.9 eV

3.0 eV

Pentacene

. 4-25 ITO/m-MTDATA(4 nm)/CuPc:(R%)Pentacene (30

nm)/C

60

(40 nm)/BCP(10 nm)/Al(100nm)

-1.0 -0.5 0.0 0.5 1.0 0 10 20 30 25.3 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Pentacene(3%) 0.0133 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -8 -7 -6 -5 -4 -3 -2 -1 0 1 J_MAX = 4.87 mA/cm2 V_MAX = 0.3 V V_OC = 0.5V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Pentacene(3%) J_SC = 6.26 mA/cm2 ηηηη = 1.46 % % % % FF = 46.6 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-26 ITO/m-MTDATA(4 nm)/ CuPc:(3%)Pentacene (30

nm)/C

60

(40 nm)/BCP(10 nm)/Al(100nm)

-1.0 -0.5 0.0 0.5 1.0 0 10 20 30 40 32.2 mA/cm2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Pentacene(5%) 0.0125 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 J_MAX = 5.72 mA/cm2 V_MAX = 0.3 V V_OC = 0.5V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Pentacene(5%) J_SC = 7.74 mA/cm2 ηηηη = 1.72 % % % % FF = 44.3 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-27 ITO/m-MTDATA(4 nm)/CuPc:(5%)Pentacene (30

nm)/C

60

(40 nm)/BCP(10 nm)/Al(100nm)

-1.0 -0.5 0.0 0.5 1.0 0 10 20 30 40 38.2 mA/cm 2 C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Pentacene(7%) 0.0089 mA/cm2

(a) J-V characteristic @ dark

0.0 0.2 0.4 0.6 -8 -7 -6 -5 -4 -3 -2 -1 0 1 J_MAX = 4.38 mA/cm2 V_MAX = 0.3 V V_OC = 0.4V C u rr e n t D e n s it y ,m A /c m 2 Voltage,V Pentacene(7%) J_SC = 6.66 mA/cm2 ηηηη = 1.31 % % % % FF = 49.3 % % % % (b) J-V characteristic @ 100 mW/cm2

. 4-28 ITO/m-MTDATA(4 nm)/CuPc:(7%)Pentacene (30

nm)/C

60

(40 nm)/BCP(10 nm)/Al(100nm)

Glass

ITO 145nm

m-MTDATA (4 nm)

CuPc :(5%)Pentacene(30nm)

C

₆₀

(40 nm)

BCP 10 nm

Al 100 nm

Glass

ITO 145nm

m-MTDATA (4 nm)

CuPc :(5%)Pentacene(30nm)

C

₆₀

(40 nm)

BCP 10 nm

Al 100 nm

7.0 eV 1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 5.1 eV 3.5 eV

m

-M

T

D

A

T

A

4.9 eV 3.0 eV

Pentacene

7.0 eV 1.9 eV

CuPc

C

₆₀

B

C

P

ITO

Al

5.0 eV 5.2 eV 6.2 eV 4.5eV 4.2 eV 3.5 eV 5.1 eV 3.5 eV

m

-M

T

D

A

T

A

4.9 eV 3.0 eV

Pentacene

. 5-1

(ITO/m-MTDATA(4 nm)/

CuPc:(5%)Pentacene (30 nm)/C

60

(40 nm)/BCP(10

nm)/Al(100nm))