應用苯并呋喃於主鏈予體－受體高分子之總體異質接面太陽能電池元件研究

- I - (benzooxadiazole, BO) (benzodithiophene) PBDTBO (Mn= 62kg mol-1) HOMO 5.7 %

PTHBO PBTTBO PTTTBO

HOMO PTHBO 1.02 V

PBTTBO (FF= 0.74) PTTTBO

5.3 %

PCyTBO PCySiTBO PCyNTBO

(300 700 nm) PCySiTBO

PC71BM 5.0 %

- II -

ABSTRACT

In this study, we selected a series of main chain donor-acceptor conjugated copolymers which synthesize by BO acceptor and different donor units for application in polymer bulk heterojunction(BHJ) solar cells.

Benzooxadiazole (BO) is a rigid, electron-deficient, coplanar ring structure as an acceptor moiety and this series of polymer materials have many of the characteristics to improve the device efficiency.

PBDTBO with high thermal decomposition temperature, good solubility, high molecular weight (Mn=62kg mol-1), and low HOMO energy level .A BHJ solar cell device provided a high power conversion efficiency(PCE) of 5.7 %. Second, we used a series of thiophene-based conjugated copolymers PTHBO, PBTTBO, and PTTTBO which showed excellent crystallinity. The PTHBO devices showed a high Voc of 1.02 V. With a highly crystallinity, PBTTBO had a high fill factor of 74%. PTTTBO showed a good PCE for 5.3 % with thermal annealing process. Finally, we used a series of conjugated copolymers featuring alternative C-, Si-, and N-bridged dithiophene-based building blocks and BO units. These polymers exhibit broad absorption in the visible range (300 700 nm) to absorbe more photon. PCySiTBO blend with PC71BM exhibited a good PCE value of 5.0 % by an additive process.

- V -

I II III V VIII X 1-1 1 1-2 2 1-3 4 1-3-1 4 1-3-2 5 1-3-3 7 1-3-4 J-V 13 1-3-5 17 1-3-6 19 1-3-7 21

- VI - 1-4 24 1-5 29 2-1 34 2-2 35 2-3 37 2-4 39 3-1 43 3-1-1 43 3-1-2 44 3-1-3 45 3-1-4 48 3-1-5 X XRD 51 3-2 53 3-2-1 PBDTBO 53

3-2-2 PTHBO PBTTBO PTTTBO

60 3-2-3 PCyTBO PCySiTBO PCyNTBO

- VII -

72

93 95

- VIII - 34 43 44 45 49 PBDTBO PCBM=1 1 54 PBDTBO PCBM 55 PBDTBO 58 PTHBO PCBM 61 PBTTBO PCBM 62 PTTTBO PCBM 63 PTHBO PCBM 64 PBTTBO PCBM 66 PTTTBO PCBM 68 PTTTBO PCBM 69 PCyTBO PCBM 73 PCyNTBO PCBM 74

- IX - PCySiTBO PCBM 78 PCySiTBO PCBM 80 PCySiTBO PCBM CN 82 PCySiTBO PCBM DIO 83 PCySiTBO fullerene 87 PCySiTBO fullerene 89

- X - 1-1 (a) (b)PEDOT PSS 5 1-2 6 1-3 8 1-4 9 1-5 10 1-6 10 1-7 11 1-8 12 1-9 I-V 13 1-10 (a) Voc n C60 (b) p Voc 14 1-11 19 1-12 (polyacetylene) 20 1-13 22 1-14 22 1-15 23 1-16 23

- XI - 1-17 (a) Chlorobenzene (b)Toluene

AFM 25 1-18 27 1-19 PBTTPD/PC71BM 28 1-20 donor acceptor 30 1-21 31 1-22 BT BO 32 3-1 TGA 44 3-2 PBDTBO PTHBO DCB UV 46 3-3 PBTTBO PTTTBO DCB UV 46 3-4 PCyTBO PCySiTBO DCB UV 46 3-5 PCyNTBO DCB UV 47 3-6 UV 48 3-7 CV 50 3-8 51 3-9 52 3-10 X 52 3-11 PBDTBO PCBM=1 1 J-V 54

- XII - 3-12 PBDTBO PCBM J-V 55 3-13 AFM 56 3-14 TEM 57 3-15 J-V 58 3-16 PBDTBO PCBM EQE 59 3-17 PTHBO PCBM J-V 61 3-18 PBTTBO PCBM J-V 62 3-19 PTTTBO PCBM J-V 63 3-20 PTHBO PCBM J-V 64 3-21 AFM 65 3-22 PBTTBO PCBM J-V 66 3-23 PBTTBO AFM 67 3-24 PTTTBO PCBM J-V 68 3-25 PTTTBO PCBM J-V 69 3-26 AFM 70 3-27 EQE 71 3-28 PCyNTBO PCBM J-V 73 3-29 PCyNTBO PCBM J-V 74 3-30 PCyTBO AFM 75

- XIII - 3-31 PCyTBO TEM 76 3-32 PCyNTBO AFM 77 3-33 PCyNTBO TEM 77 3-34 PCySiTBO PCBM J-V 78 3-35 AFM 79 3-36 PCySiTBO PCBM J-V 80 3-37 PCySiTBO PCBM AFM 81 3-38 PCySiTBO PCBM CN J-V 82 3-39 PCySiTBO PCBM DIO J-V 83

3-40 PCySiTBO PCBM DIO AFM 85

3-41 PCySiTBO TEM 86

3-42 PCySiTBO fullerene J-V 87

3-43 PCySiTBO fullerene AFM 88

3-44 PCySiTBO fullerene J-V 89

3-45 PCySiTBO PC71BM AFM 90

3-46 PCySiTBO PC71BM TEM 90

3-47 PCySiTBO ICBA AFM 91

- 1 -

1-1

International Energy Agency, IEA 2009 Energy Technology Perspective 2009 1 2050

2005 2.5

CO2 2.3

3×1024 10

- 2 -

1-2

1839 Alexandre

Edmond Becquerel

photovoltaic effect 1954

D. M. Chapin, C. S. Fuller G. L. Pearson Si P-N

junction 6% 2 1 25% 20% α-Si

- 3 - 2

- - Ga In P As

GaAs CdTe CuInGaSe2 CIGS 1 1.6 eV 1.4 1.5 eV

Multi-junction

GaInP/GaAs/Ge 32 %

3

DSSC Dye-Sensitized Solar Cells TiO2 ZnO

Sensitized

11%

4

- 4 - 6.7 % 8.6 %3,4

polymer solar cells

flexibility

spin-coating doctor-blading

1-3

1-3-1 5

1-1(a) normal structure

ITO Indium Tin Oxide

- 5 -

Hole Transport Layer ITO

Active Layer P donor

N acceptor

Ca Al

1-1 (a) (b)PEDOT PSS

1-3-2 5

P donor

HOMO Highest Occupied Molecular Orbital LUMO Lowest Unoccupied Molecular Orbital N acceptor

donor acceptor (a)

- 6 -

( 1-2)

1-2 (1) (2)

(3) (4) 20b

(1) light absorption

donor HOMO LUMO

exciton (2) exciton diffusion 4 20 nm donor acceptor acceptor acceptor (3) charge separation donor

- 7 - acceptor (4) charge collection donor acceptor 1-3-3 5 Graphene ITO

MoOx NiO V2O5 WO3 PEDOT

PSS

PEDOT PSS

hygroscopic acidic ITO

PEDOT PSS 6,7

Heeger

ITO 9 nm MoO3

- 8 - air-stable PEDOT PSS 6 ( 1-3) normal inverted PEDOT PSS ITO

PEDOT PSS ITO ITO

1-3 5f

single-layer device

bilayer devices bulk

- 9 -

1-4 (a) single-layer ; (b)

bilayer ;(c) bulk heterojunction 5c

(1) single-layer device

1959 H. Kallmann M. Pope anthrathcene 8

1978 T.

Feng merocyanine

1-5

- 10 -

1-5

(2) bilayer devices

1986 C.W. Tang

CuPc donor perylene acceptor

donor acceptor 10

0.95 %

P N (

1-6)

excition diffusion length

10 20 11

1-6

- 11 - 100 200

P-N 40

P-N

(3) bulk heterojunction devices

P N

( 1-7) 1995 Heeger MEH-PPV

PCBM 1.5% 12

- 12 -

1-8

P-N P N PCBM

~psec C60

photo induced charege

transfer 13

P3HT/PCBM

P3HT PCBM

- 13 - 1-3-4 J-V I-V J-V 1-9 I-V 5 1-9 I-V J-V

short circuit current Jsc y

open circuit voltage Voc x J-V

- 14 -

(1) Voc

P N

quasi Fermi level P

HOMO N LUMO C.Brabec 15 N LUMO ( 1-10(a)) Scharber 26 Voc HOMO ( 1-10(b)) 16 1-10 (a) Voc n C60 (b) p Voc (2) Jsc photoinduced charge carrier density carrier mobility

- 15 - n e μ E P-N morphology 16,17 (3) FF, fill factor series

resistance, Rs shunt resistance, Rsh

-generation-recombination current surface recombination

edge isolation p-n

leakage current

Rsh=V/Ileak Rsh

- 16 - oc sc

V

I

P

FF



max max max max IP VP P  FF 1-9 x y max P V max P I FF VP_max IPmax Voc Jsc

(4) η Power Conversion Efficiency

Pmax Pin FF sc I Voc FF in oc sc in p p in

P

V

I

FF

P

I

V

P

P

_



_







max max max

- 17 -

(5) EQE External Quantum Efficiency



 











 















A

nm

W

P

I

q

hc

P

I

photons

electrons

EQE

in sc in sc







1240

sec

/

sec

/

0

h Planck constant c EQE

1-3-5

- 18 - conjugation

polyacetylene PA 1970 Shirakawa

All-Trans-Polyacetylene

(SN)x Alan G. MacDiarmid Alan J.

Heeger 1000 S/cm 18 1977 2000 spin-coating 100

- 19 - 1-3-6 band theory energy band Valance Band, VB Conduction Band, CB

Energy gap, Eg Vacuum level

Ionization Potential, IP Vacuum level Electron Affinity, EA 1-11

- 20 - Eg < 0eV 3.5 Eg > 3.5eV 0eV < Eg < 3.5eV σ π bonds π delocalized 1-12 polyacetylene π 1-12 (polyacetylene)

- 21 - 1979 Heeger 19 _π π-π* π SSH Su-Schrieffer-Heeger model 1-3-7 20 ( 1-13) P3HT rr-P3HT∕PCBM 5 %14 P3HT 650 nm 1.9eV extinction coefficient

- 22 - 1-13 donor acceptor ( 1-14) HOMO LUMO 1-15 HOMO LUMO 1-14

- 23 -

1-15

1-16

- 24 - 1-4 5,21 polymer∕fullerene (1) Heeger 12 C60 interpenetrating network C60 phase separation p-n

C60 PCBM [6,6]-phenyl-C61-butyric acid methyl

ester N

Shaheen MDMO-PPV PCBM

Toluene Chlorobenzene

- 25 - Atomic Force Microscopy

23

Chlorobenzene

( 1-17)

1-17 (a) Chlorobenzene (b)Toluene

AFM 23

(2) Polymer∕Fullerene

polymer fullerene

PPV PCBM PCBM 80 wt% (i.e. ratio 1 4)

Van Duren AFM TEM PL TOF-SIMS

67 wt% PCBM 24 rr-P3HT PCBM PCBM 50% P3HT P3HT PCBM 1 0.8~1 14,25

- 26 - (3) annealing 2005 Y. Yang P3HT PCBM 4 % 26 solvent annealing 1.6Ωcm-2 self-organization 27 (4) Bazan 2006 P3HT PCBM

(alkyl thiol) photoresponsivity

28 Bazan Heeger PCPDTBT PC71BM 1-8-octanedithiol 2.8 % 5.5 % 29, 30 Y. Yang 2008 P3HT PCBM ( 1-18) 31

- 27 - 1-18 (a)-(c) (d)-(f) 31 1-18 (a)-(c) P3HT DCB PCBM cluster P3HT (d)-(f) 1,8-octanedithiol OT DCB 200 DCB OT PCBM OT PCBM cluster P3HT 1,8-octanedithiol P3HT PCBM 8.14 mA/cm2 FF 31% 63% DIB

- 28 -

Diiodobutane DIH Diiodohexane DIO Diiodooctane

PBTTPD∕PC71BM X-ray

grazing-incidence small-angle X-ray scattering, GISAXS X-ray grazing-incidence wide-angle X-ray scattering, GIWAXS

PC71BM

PC71BM ( 1-19)

9.1 mA/cm2 12 mA/cm2 5.0 %

7.3 % 32

- 29 -

1-5

1.

2.

3. HOMO Voc 1-20 Voc

donor HOMO acceptor LUMO HOMO

4. LUMO LUMO

LUMO

- 30 -

LUMO LUMO 0.3eV

1-20 donor acceptor

Benzooxadiazole acceptor donor

- 31 - S S N O N C8H17O OC8H17 S S O O S N O N C8H17O OC8H17 S N O N C8H17O OC8H17 S S S C8H17 C8H17 S N O N C8H17O OC8H17 S S C8H17 C8H17 S PBDTBO PTHBO PBTTBO PTTTBO N O N C8H17O OC8H17 S S S S Si N O N C8H17O OC8H17 S S S S N C8H17 C8H17 N ON C8H17O OC8H17 S S S S C8H17 C8H17 C8H17 C8H17 PCyTBO PCySiTBO PCyNTBO n n n n n _n n 1-21 benzothiadiazole BT benzooxadiazole BO ( 1-22) BT BT BT 5 ~ 6 %33 Bo HOMO Voc HOMO LUMO Voc 34 BT R. A. J. Janssen

- 32 -

BT BO Voc, 0.78eV

BT Voc, 0.66eV Voc 0.12eV FF BO FF, 0.6 BT FF, 0.44 BT 35,36 BO Jsc 37, 38 N S N N O N BT BO 1-22 BT BO doner Cyclopentadithiophene

- 33 - 5, 20

- 34 - 2-1 PBDTBO PTHBO PBTTBO PTTTBO PCyTBO PCySiTBO PCyNTBO

PCBM [6,6]-phenyl-C61-butyric acid methyl ester Nano-C PC71BM [6,6]-phenyl-C71-butyric acid methyl ester Nano-C ThCBM [6,6]-thieno-C61-butyric acid methyl ester Nano-C IC60BA indene-C60 bisadduct

bis-PCBM [6,6]-phenyl-C61-bis-butyric acid methyl

ester

Nano-C

- 35 -

ITO MA03 Merck

ITO HNO3 / HCl

Chloroform anhydrous Aldrich

Chlorobenzene anhydrous Aldrich

Dichlorobenzene anhydrous Aldrich

1,2,4-Trichlorobenzene anhydrous Aldrich

1,8-Diiodooctane anhydrous Aldrich

1-Chloronaphthalene anhydrous TCI

PEDOT PSS BATRON 4071 Bayer AG

2-2

P

1. Gel Permeation Chromatography GPC Water 410

Didderential Refractometer Water 600 Controller Waters Styragel Column

polystyrene PS

2.0 mg 1.0 mL Tetrahydrofuran THF Toluene

- 36 -

2. Thermal Gravimetric Analyzer TGA TA Instrument

Q500

2 10 10 /min

40ml/min

Td

3. UV-Vis Absorption spectrometry

Agilent-8453

1×10-5 M 1

wt%

4. Cyclic Voltammetry CV AVD-164

Autolab AVD-164 - 0.1 M

Tetrabutylammonium hexafluorosphate TBAPF6 Acertonitrile

10mL 1 10mg/mL THF

Ag/Ag+ reference electrode

ferrocene/ferrocenium Fc/Fc+ glassy carbon working electrode counter electrode

- 37 -

100 mV/S -200 ~ 2000 mV -200 ~ -2000 mV

5. X-ray High Resolution X-ray Diffractometer

XRD Bruker D8

Kα X X

2-3 (1) ITO

Merck 3×3cm2 ITO ITO

NaCO3

80 ITO 2 NaOH

ITO

UV-Ozone UV-Ozone

- 38 - contact angle (2) PEDOT PSS 5000rpm 40 ITO 130 20 20 30 nm ITO (3) ULVAC CRTM-6000 defect

- 39 -

mask

Mechanical pump Cryo pump 8×10-6

300Å 1000Å 20

2-4

1. Nespot 66902-150W Xenon Lamp Solar Simulator

I-V AM 1.5G

AM 1.5G Photo

Diode 100 mW/cm2

2. I-V Keithley 4200

- 40 - -1 V~2 V

ITO

0.04 cm2 J-V

Voc Jsc FF

Power Convertion Efficient η

3. EQE

EQE

J-V EQE

J-V 10%

4. Stylus Profiler α-step Veeco Dektak 150

(Stylus Profiler)

- 41 -

morphology

AFM tapping mode 5×5 μm2

morphology Rms AFM

piezoelectric ceramic scanner

AFM

contactmode non-contact mode tapping mode

Van Der Waals force

- 42 -

6. Transmission Electron Microscope TEM EFI T12

CCD

TEM

PEDOT PSS

- 43 -

3-1 3-1-1

GPC

Mw (KDa) Mn (KDa) PDI

PBDTBO 254.2 62.1 4.1 PTHBO 52.8 35.2 1.5 PBTTBO 72.4 42.6 1.7 PTTTBO 74.7 41.5 1.8 PCyTBO 36.5 22.8 1.6 PCySiTBO _{45.4 25.2 1.8} PCyNTBO 45.2 23.8 1.9

- 44 -

3-1-2

TGA

thermal decomposition temperature Td Td

5% Td 300oC Td o C 100 200 300 400 500 20 30 40 50 60 70 80 90 100 PBDTBO PTHBO PBTTBO PTTTBO PCyTBO PCySiBO PCyNTBO W eigh t los s (% ) Temperature(oC) PBDTBO 330 PTHBO 310 PBTTBO 312 PTTTBO 315 PCyTBO 316 PCySiTBO 312 PCyNTBO 316 3-1 TGA

- 45 -

3-1-3

-optical bandgap, Egopt 3-2 3-3 3-4

3-5 DCB 10–5 M 300 700 nm λmax (nm) solution λmax (nm) film λonset (nm) film opt g E (eV) a RT Heating PBDTBO 415, 575 416, 578 712 1.74 PTHBO 605, 660 602, 650 605, 662 724 1.71 PBTTBO 574 558 600 726 1.70 PTTTBO 596 558 600 720 1.72 PCyTBO 640 645 777 1.59 PCySiTBO 611 623, 678 756 1.64 PCyNTBO 631 632 777 1.59 a Film onset

- 46 - 300 400 500 600 700 800 0.0 0.2 0.4 0.6 0.8 1.0 PBDTBO in solution film No rmaliz ed abso rption (a.u.) Wavelength(nm) 300 400 500 600 700 800 0.0 0.2 0.4 0.6 0.8 1.0 PTHBO in solution heat solution film Normal ized abs orption (a .u. ) Wavelength(nm) 3-2 PBDTBO PTHBO DCB UV 300 400 500 600 700 800 0.0 0.2 0.4 0.6 0.8 1.0 PBTTBO in solution heat solution film N o rma liz ed a bs o rpt io n ( a .u.) Wavelength(nm) 300 400 500 600 700 800 0.0 0.2 0.4 0.6 0.8 1.0 PTTTBO in solution heat solution film N o rma liz ed a bs o rpt io n ( a .u.) Wavelength(nm) 3-3 PBTTBO PTTTBO DCB UV 300 400 500 600 700 800 0.0 0.2 0.4 0.6 0.8 1.0 PCyTBO in solution film No rmaliz ed abso rption (a.u.) Wavelength(nm) 300 400 500 600 700 800 0.0 0.2 0.4 0.6 0.8 1.0 PCySiTBO in solution film No rmaliz ed abso rption (a.u.) Wavelength(nm) 3-4 PCyTBO PCySiTBO DCB UV

- 47 - 300 400 500 600 700 800 0.0 0.2 0.4 0.6 0.8 1.0 PCyNTBO in solution film No rmaliz ed abso rption (a.u.) Wavelength(nm) 3-5 PCyNTBO DCB UV 3-2 3-5 400 nm

localized π–π* charge transfer

ICT, intramolecular charge transfer PBTTBO PTTTBO PCySiTBO

red-shifted

aggregation π–π π–π

stacking PBTTBO PTTTBO

60oC blue-shifted

π–π stacking

π–π stacking PBDTBO

- 48 - π–π stacking PTHBO 605 nm 660 nm π–π stacking 350 400 450 500 550 600 650 700 750 800 0.0 2.0x104 4.0x104 6.0x104 Abso rptio n Coeffi cient (cm -1 ) Wavelength (nm) Film PTHBO PBTTBO PTTTBO 300 400 500 600 700 800 0 1x104 2x104 3x104 4x104 5x104 Film PCyTBO PCySiTBO PCyNTBO Abso rption Coefficient (cm -1 ) Wavelength (nm) 3-6 UV 3-6 3-1-4 Cyclic Voltammeter CV Ea Electron Affinity

Ip Ionization Potential HOMO LUMO

- 49 - ox onset

E

(V) Eonsetred (V) HOMO (eV)a LUMO (eV)b ec g

E

_(eV)c PBDTBO 0.47 –1.64 –5.27 –3.16 2.11 PTHBO 0.67 –1.21 –5.47 –3.59 1.88 PBTTBO 0.33 –1.80 –5.13 –3.00 2.13 PTTTBO 0.48 –1.74 –5.28 –3.06 2.22 PCyTBO 0.18 –1.76 –4.98 –3.04 1.94 PCySiTBO 0.22 –1.76 –5.02 –3.04 1.98 PCyNTBO 0.09 –1.99 –4.89 –2.81 2.08 a

HOMO determined from onset of oxidation

b

LUMO determined from onset of reduction

c

Electrochemical bandgap Egec LUMO HOMO

HOMO LUMO ox onset E vs. Fc/Fc+ 4.8 ferrocene BO HOMO -5.2 eV HOMO 39 Voc HOMO

- 50 -

LUMO PBDTBO PTHBO PTTTBO HOMO

Voc

- 51 - ec g E ( opt g E ) 40,41b 41 3-8 3-8 3-1-5 X XRD X-ray X (100) (010) (100) d-spacing (010) π–π ( 3-9 )

- 52 -

3-9

3-10 (010) π–π

PBTTBO PTTTBO PCySiTBO 4o

(100) PBTTBO

(200) (300)

PBTTBO

- 53 -

3-2

PCBM

Chloroform CF Chlorobenzene CB othro-Dichlorobenzene DCB 1,2,4-Trichlorobenzene TCB 3-2-1 PBDTBO S S N O N C₈H₁₇O OC₈H₁₇ S S O O PBDTBO n CF DCB PBDTBO

- 54 - PBDTBO PCBM=1 1 Solvent Voc (V) Jsc (mA cm-2) PCE (%) FF CF 0.86 10.0 3.4 0.39 DCB 0.80 8.7 3.8 0.55 0.0 0.2 0.4 0.6 0.8 -10 -8 -6 -4 -2 0 PBDTBO:PC 61BM(1:1) CF DCB C u rr en t d en si ty ( m A /c m 2 ) Voltage (V) 3-11 PBDTBO PCBM=1 1 J-V J-V 3-11 DCB CF FF DCB FF DCB

- 55 - PCBM 1 1 1 4 PCBM J-V 3-12 PBDTBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF 1:1 0.86 10.4 5.7 0.64 1:2 0.81 9.7 4.5 0.57 1:3 0.80 8.5 4.0 0.59 1:4 0.80 7.1 3.2 0.57 0.0 0.2 0.4 0.6 0.8 -10 -8 -6 -4 -2 0 Curr ent density ( mA/c m 2 ) Voltage (V) PBDTBO:PC 61BM(w/w) 1:1 1:2 1:3 1:4 3-12 PBDTBO PCBM J-V

- 56 - PCBM 1 1 1 4 Voc Jsc 10.4mA/cm 2 7.1mA/cm2 3-13 AFM (a)1:1(b)1:2(c)1:3(d)1:4

- 57 -

3-13 PBDTBO PCBM AFM AFM

PCBM 50 Rms PCBM PCBM aggregation PCBM cluster 3-14 TEM (a)1:1(b)1:2(c)1:3(d)1:4 TEM PBDTBO PCBM TEM ( 3-14) PCBM PCBM AFM TEM 1 1

- 58 - 1,8-diiodooctane DIO 1-chloronaphthalene ( CN ) PBDTBO PCBM=1 1 J-V 3-15 PBDTBO Voc (V) Jsc (mA/cm2) PCE (%) FF DIO 2% 0.83 10.99 4.66 0.51 CN 2% 0.85 10.40 5.53 0.63 -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 -12 -10 -8 -6 -4 -2 0 PBDTBO:PC₆₁BM( 1:1 ) 2% DIO 2% CN Curr ent dens ity ( mA /cm 2 ) Voltage (V) 3-15 J-V DIO Jsc Voc FF DCB

- 59 - PCBM DIO CN CN PBDTBO PCBM CN 3-16 PBDTBO∕PCBM EQE 1 1 EQE 1 1 9.7 mA/cm2 6% EQE 1 1 350 400 450 500 550 600 650 700 750 800 0 10 20 30 40 50 60 70 E Q E % Wavelength (nm) PBDTBO/PC₆₁BM 1:1 1:2 1:3 1:4 3-16 PBDTBO PCBM EQE

- 60 -

3-2-2 PTHBO PBTTBO PTTTBO

S N O N C8H17O OC8H17 S N O N C8H17O OC8H17 S S S C8H17 C8H17 S N O N C8H17O OC8H17 S S C8H17 C8H17 S PTHBO PBTTBO PTTTBO n n n (thiophene) BO

thiophene bithiophene thienothiophene

PBDTBO PTHBO

PBTTBO PTTTBO CF DCB

J-V

- 61 - PTHBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF 1:1 0.96 -7.5 3.3 0.45 1:2 0.99 -4.3 1.4 0.34 1:3 0.92 -2.6 0.9 0.39 1:4 0.91 -1.6 0.6 0.38 3-17 PTHBO PCBM J-V

- 62 - PBTTBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF 1:1 0.74 -7.0 3.7 0.72 1:2 0.73 -5.0 2.3 0.64 1:3 0.68 -3.7 1.1 0.46 1:4 0.72 -3.3 1.0 0.43 3-18 PBTTBO PCBM J-V

- 63 - PTTTBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF 1:1 0.85 -8.3 4.5 0.63 1:2 0.83 -6.4 3.7 0.68 1:3 0.82 -5.8 2.8 0.58 3-19 PTTTBO PCBM J-V Voc

HOMO PBTTBO PTTTBO FF

PCBM 1 1

- 64 - PTHBO 35.2 kDa 4.2% (pre-anneal) J-V 3-20 PTHBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF None anneal 0.99 -9.4 4.2 0.45 90oC 1.02 -8.3 4.3 0.50 100oC 1.02 -9.0 4.5 0.49 110oC 1.02 -8.4 4.3 0.50 3-20 PTHBO PCBM J-V

- 65 - 90 110oC 20 100oC 4.5 % 7 % 1.02 V FF AFM ( 3-21) Rms 9.3 nm 8.8 nm phase PCBM

3-21 AFM (a) none anneal (b) pre-anneal

- 66 - J-V 3-22 PBTTBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF None add. 0.74 -7.0 3.7 0.72 1%CN 0.73 -8.0 4.3 0.73 2%CN 0.72 -7.5 3.8 0.70 1%DIO 0.72 -6.7 3.6 0.74 2%DIO 0.70 -6.5 3.3 0.72 3-22 PBTTBO PCBM J-V CN DIO 1%CN 7.0 mA/cm2 8.0 mA/cm2

- 67 - 3.7 % 4.3 % CN PCBM DIO CN AFM ( 3-23) PBTTBO PCBM

3-23 PBTTBO AFM (a) (b) 1%CN

Rms 3.8 nm 3.3 nm height phase

- 68 - PTTTBO J-V 3-24 100 nm 5.04 % PTTTBO PCBM (rpm) Voc (V) Jsc (mA/cm2) PCE (%) FF (nm) 1000 0.85 -8.3 4.5 0.63 130 1200 0.86 -10.4 4.8 0.55 115 1400 0.85 -10.7 5.0 0.55 103 1600 0.84 -10.5 4.5 0.51 86 3-24 PTTTBO PCBM J-V

- 69 - PTHBO pre-anneal 20 J-V 4-25 PTTTBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF None anneal 0.85 -10.7 5.0 0.55 90oC 0.85 -11.5 5.1 0.52 100oC 0.85 -11.6 5.3 0.54 110oC 0.85 -11.1 4.7 0.50 3-25 PTTTBO PCBM J-V 90 110oC 20 100oC 5.3 % PTHBO PTTTBO FF PTTTBO

- 70 -

PCBM

FF AFM ( 3-26)

Rms 3.3 nm 1.0 nm

height phase

3-26 AFM (a) none anneal (b) pre-anneal

3-27 EQE PTHBO

- 71 -

PTTTBO 580 nm 60 % 3-6 PBTTBO

PTHBO PBTTBO PTTTBO EQE

8.6 mA/cm2 7.5 mA/cm2 11.1 mA/cm2

3-27 EQE

4 %

Voc Jsc FF

- 72 -

3-2-3 PCyTBO PCySiTBO PCyNTBO

N O N C8H17O OC8H17 S S S S Si N O N C8H17O OC8H17 S S S S N C8H17 C8H17 N O N C8H17O OC8H17 S S S S C8H17 C8H17 C8H17 C8H17 PCyTBO PCySiTBO PCyNTBO n n n cyclopentadithiophene donor C Si N PCySiTBO PCyTBO PCyNTBO J-V 3-28 3-29

- 73 - PCyTBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF (nm) PCyTBO:PCBM 1:2 0.63 -8.0 2.8 0.56 85 Anneal at 100oC 0.64 -7.4 2.4 0.50 95 0.5%CN 0.63 -8.6 3.0 0.56 87 1%CN 0.62 -8.6 2.8 0.52 87 3 -28 PCyNTBO PCBM J-V

- 74 - PCyNTBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF (nm) PCyNTBO:PCBM 1:1 0.49 -5.1 1.0 0.38 94 Anneal at 100oC 0.50 -3.6 0.6 0.32 86 0.5% CN 0.58 -5.1 1.2 0.40 95 3-29 PCyNTBO PCBM J-V PCyTBO 1 2 90 nm CN 8.0 mA/cm2 8.6 mA/cm2

- 75 -

Rms 0.89 nm 1.03 nm

3-30 PCyTBO AFM (a) (b) 0.5%CN

TEM TEM ( 3-31)

TEM PCBM cluster

- 76 - 3-31 PCyTBO TEM PCyNTBO 1 1 90 nm 0.5%CN PCyTBO HOMO Voc 0.5 V AFM ( 3 -32) PCyTBO Rms TEM TEM ( 3-33) PCyNTBO PCyTBO 1.0 % 1.2 % TEM

- 77 -

3-32 PCyNTBO AFM (a) (b) 0.5%CN

3-33 PCyNTBO TEM

PCyTBO PCyNTBO PCySiTBO

HOMO Voc Jsc XRD

FF Si thiophene

- 78 - DCB J-V 3-34 PCySiTBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF (nm) 1:1 0.68 -9.2 4.0 0.64 101 1:2 0.68 -5.2 2.2 0.63 108 1:3 0.70 -3.3 1.4 0.61 94 3-34 PCySiTBO PCBM J-V 1 1 PCySiTBO Voc Jsc FF AFM( 3-35)

- 79 - Rms 0.96 nm 2.81 nm 3-35 AFM (a) 1:1 (b) 1:2(c) 1:3 TCB CB 1 1 J-V 3-36

- 80 - PCySiTBO PCBM Voc (V) Jsc (mA/cm2) PCE (%) FF DCB 0.68 -9.2 4.0 0.64 TCB 0.70 -6.1 2.2 0.51 CB 0.70 -4.1 1.3 0.45 3-36 PCySiTBO PCBM J-V DCB AFM ( 3-37) CB phase TCB phase DCB Rms TCB TCB TCB

- 81 -

3-37 PCySiTBO PCBM AFM

CN DIO

J-V 3-38

- 82 - PCySiTBO PCBM CN Voc (V) Jsc (mA/cm2) PCE (%) FF None 0.68 -9.2 4.0 0.64 0.5%CN 0.67 -10.0 4.1 0.61 1%CN 0.68 -9.2 4.2 0.67 2%CN 0.68 -9.5 4.3 0.66 3-38 PCySiTBO PCBM CN J-V

- 83 - PCySiTBO PCBM DIO Voc (V) Jsc (mA/cm2) PCE (%) FF None 0.68 -9.2 4.0 0.64 0.5%DIO 0.67 -10.3 4.5 0.65 1%DIO 0.67 -10.3 4.6 0.66 2%DIO 0.66 -10.8 4.7 0.66 4%DIO 0.67 -8.9 3.9 0.65 3-39 PCySiTBO PCBM DIO J-V CN DIO CN CN DIO DIO DIO DIO 2% 9.15 mA/cm2 10

- 84 - mA/cm2 4.0 % 4.7 % AFM ( 3-40) Rms height phase DIO PCBM TEM PCyTBO TEM ( 3-41) TEM PCBM PCBM

- 85 -

- 86 - 3-41 PCySiTBO TEM 2%DIO PCBM Bis-PCBM ThCBM PCBM Voc Jsc J-V 3-42 Bis-PCBM LUMO Voc 0.8 V PCBM 42 PCBM AFM ( 3-43) phase Rms PCBM Bis-PCBM ThCBM PCBM AFM ( 3-43)

- 87 - PCySiTBO fullerene Voc (V) Jsc (mA/cm2) PCE (%) FF PCBM 0.66 -10.8 4.7 0.66 Bis-PCBM 0.80 -7.6 2.8 0.45 ThCBM 0.65 -10.7 4.1 0.60 3-42 PCySiTBO fullerene J-V

- 88 -

3-43 PCySiTBO fullerene AFM

PC71BM ICBA C70

C60 ICBA

LUMO Voc

- 89 - PCySiTBO fullerene Voc (V) Jsc (mA/cm2) PCE (%) FF PC71BM 0.64 -6.7 2.3 0.53 PC71BM 2%DIO 0.64 -13.8 5.0 0.57 ICBA 0.87 -3.2 1.4 0.50 ICBA 2%DIO 0.84 -5.0 1.8 0.43 3-44 PCySiTBO fullerene J-V PC71BM ICBA 2% DIO PC71BM DIO AFM( 3-45) TEM( 3-46) AFM height TEM

- 90 - 3-45 PCySiTBO PC71BM AFM 3-46 PCySiTBO PC71BM TEM ICBA PCBM PC71BM Voc AFM ( 3-47) Rms 4.3 nm 1.91 nm phase

- 91 -

3-47 PCySiTBO ICBA AFM

400 500 600 700 800 0 20 40 60 80 E Q E ( % ) Wavelength (nm) PCySiTBO/PC 61BM PCyTBO/PC 61BM PCyNTBO/PC 61BM PCySiTBO/PC 71BM 3-48 EQE

- 92 -

3-48 EQE PCySiTBO

PCBM PC71BM 350 nm 450 nm

EQE PCyTBO

PCySiTBO PCyNTBO EQE 8.2 mA/cm2

10.2 mA/cm2 4.9 mA/cm2

PCySiTBO PC71BM

- 93 - p-n benzooxadiazole, BO N AFM TEM PBDTBO (Mn=62kg mol-1) HOMO DCB PCBM 1 1 Voc 0.86 V Jsc 10.4 mA cm -2 FF 0.64 5.7 %

PTHBO PBTTBO PTTTBO

HOMO PBTTBO PTTTBO

DCB PCBM 1 1 PTHBO 100oC 20 4.5 % Voc 1.02 V Jsc 9.0 mA cm-2 FF 0.49 PBTTBO 1%CN 4.3 % Voc 0.73 V Jsc 8.0 mA cm -2 FF 0.73 PTTTBO

- 94 - 100oC 20 Voc 0.85 V Jsc 11.6 mA cm-2 FF 0.54 5.3 % PCyTBO PCySiTBO PCyNTBO (300 700 nm) PCyTBO PCBM 1 2 DCB 0.5%CN 3.0 % Voc 0.63 V Jsc 8.6 mA cm-2 FF 0.56 PCyTBO PCBM DCB 1 1 0.5%CN 1.2 % Voc 0.85 V Jsc 5.1 mA cm-2 FF 0.40 PCySiTBO PC71BM 1 1 DCB 2%DIO 5.0 % Voc 0.64 V Jsc 13.8 mA cm -2 FF 0.57

- 95 -

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