1

1

Architecture, process, and materials for efficient inorganic-organic hybrid solar cells

April 13, 2015

Sang Il Seok

Center for Solar Energy Materials Research,Korea Research Institute of ChemicalTechnology, Korea(seoksi@krict.re.kr)

Future Solar cells Lab., Department of EnergyScience, Sungkyunkwan University, Korea.(seoksi@skku.edu)

2

Global Solar Market Outlook

• 2014 Global Demand Forecast : 47GW• 14GW/China, 10GW/ EU (3GW/UK, 2.5GW/Germany..), 8GW/Japan,

7GW/USA, 8GW/ROW (India, MEA, South America, South Africa, ..)• Supply capacity~63GW; effective capacity~45GW • Transition to supply-driven market in 2014

• 2013 Total Installation: 37 GW• 11.3GW/China, 10.3GW/EU, 7.5GW/Japan, 4.8GW/USA, 4.1GW/ROW

~60GW in 2015

Sources: RPIA (European PV industry association)

2

3

Adv. Mater. 26, 1622–1628 (2014)

>20%

> 8%

KRICT hybrid solar cells

4

KRICT hybrid solar cells

3

5

Outline

State-of-art of solar cellsResearch scheme: Why inorganic-organic heterojunction hybrid solar cells? Inorganic-organic hybrid solar cells Sb2S(e)3-based systems APbX3 perovskite-based systems A =CH3NH3, HN=CHNH2; x=I, Br. ClSummary

6

Solar cells

silicon

Polycrystalline (CIGS)

Dye-sensitized solar cell(Solid-state DSSC)

II-VI compounds (CdTe)III-V compounds (GaAs)

free electron –hole pair

bound electron-hole pair

Quantum dots solar cells(Nano-oxide and polymer)

I

II

III Inorganic-organicHybrid solar cells

Organic solar cells(Tandem cells)

State-of-the- Art of Solar cells

Our research area

Main issues in solar cells are Conversion Efficiency Long-term stability Fabrication cost

4

7

eV-3

-4

-5

-6

-7

FTO

TiO2

Sb2S(e)3

e

h

P3HT PCPDTBT PCDTBT PTAA

Au5.25.5

5.15.25.3

eV-3

-4

-5

-6

-7

FTO HTMsAu

TiO2

APbX3

e

h

HTMs:

P3HT: poly(3-hexylthiophene)PCPDTBT: poly(2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b’]dithiophene)-alt-4,7(2,1,3-benzothiadiazole)PCPTBT: poly (N-9′′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole) PTAA: poly(triarylamine)

Inorganic-organic hybrid solar cells

8

e-

CB

VB

VB

CB

LUMO

HOMO

h+

mp-TiO2

Sb-Chs Polymer

AuIh

Ie

Ih

T

T

1. Ie: Electron injection2. Ie: Hole injection3. T: Transfer

Architecture

Transparent conductive oxide (F-doped SnO2, FTO)

MesoporousTiO2 (mp-TiO2)

Sb-Chs

Compact TiO2blocking layer

Conjugated polymer

PC60(or 70)BMPEDOT:PSS

AuQDs or extremely thin layer

- PC60BM / phenyl-C60-butyric acid methyl ester- PEDOT:PSS / poly(3.4-ethylenedioxythiophene) poly(sty

renesulfonate)

Sb-CHs-based inorganic-organic hybrid solar cells

5

9

20 30 40 50 60 70 800

100

200

300

400

500

600

Inte

ns

ity

(a

rb.

un

it)

2 theta (deg)

Sb2S

3 CBD on Glass

PDF 042-1393 Stibnite

FTO coatedsubstrate

CBD Process

XRD pattern of Sb2S3 annealed at ~300 oC after CBD

Sb2S3

TiO2

Precursors: SbCl3 and Sodium thiosulfate

Nanostructured Sb2S3/P3HT heterojunction solar cells

Sb2S3: a high absorption coefficient (1.8 × 105 cm–1 at 450 nm) and optimum bandgap (Eg = 1.7 eV)

10

eV-3

-4

-5

-6

-7

FTO

TiO2

Sb2S3

e

h

P3HT

Au5.2

5.1

P3HT: poly(3-hexylthiophene)

mp-TiO2/Sb2S3/P3HT hybrid solar cells

6

11

0.0 0.2 0.4 0.60

5

10

15

1 h 2 h 3 h 4 h

Cu

rren

t d

ensi

ty (

mA

cm

-2)

Potential (V)

mp-TiO2/P3HT/Au

400 500 600 700 800

0

20

40

60

80

IPC

E(%

)

Wavelength(nm)

1 h 2 h 3 h 4 h

x 2

mp-TiO2/P3HT/Au

CBD time (h) for Sb2S3 Jsc[mA cm-2] Voc[mV] FF[%] Eff.[%]0 0.63 475 29.2 0.0921 5.3 424 64.1 1.482 9.1 465 65.5 2.923 12.3 556 69.9 5.064 11.0 535 63.8 3.97

Nano Letters, 10, 2609 (2010)

Incident-photon-to-current conversion efficiency (IPCE)

Current density-voltage (J-V) curves

Nanostructured Sb2S3/P3HT heterojunction solar cells

12

Stability with time

0 200 400 600 80010

12

14

500

600

700

60

70

80

4

5

6

Jsc

(mA

cm

-2)

Time (hours)

Vo

c (

mV

)

FF

(%

)

Eff

. (%

)

Time [hours]

Jsc [mA/ cm2]

Voc[mV]

Ff[%]

Eff.[%]

0 12.3 556 69.7 5.0972 12.3 556 69.9 5.09

216 12.1 566 69.4 5.09360 12.2 556 68.1 4.88576 12.1 566 64.1 4.66720 11.8 576 66.5 4.77

0.0 0.2 0.4 0.6-5

0

5

10

15

Ph

oto

curr

ent

de

nsi

ty(m

A/c

m2 )

Voltage(V)

0 day

30 days

Reproducibility: OK !

Nanostructured Sb2S3/P3HT heterojunction solar cells

7

13

mp-TiO2/Sb2S3/HTMs

Inorganic-organic hybrid solar cells

14

Conductingpolymers

Bandgap(eV)

LUMO(eV)

HOMO(eV)

Hole mobility(cm2V-1s-1)

P3HT 2.0 -3.2 -5.2 4.0 x 10-4 (a)

PCPDTBT 1.45 -3.55 -5.3 4.5 x 10-4 (a)

PCDTBT 1.9 -3.6 -5.5 1.0 x 10-4 (a)

PTAA 3.0 -2.2 -5.2 ~4 x 10-3 (b)

a: Space charge limited current (SCLC) hole mobilityb: Hole mobility from field effect transistor

Optical and electrical properties of P3HT, PCPDTBT, PCDTBT, and PTAA

P3HT: poly(3-hexylthiophene)PCPDTBT: poly(2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b’]dithiophene)-alt-4,7(2,1,3-benzothiadiazole)PCPTBT: poly (N-9′′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole) PTAA: poly(triarylamine)

J. AM. CHEM. SOC. 2009, 131, 10814–10815

Nanostructured Sb2S3/various CPs heterojunction solar cells

8

15

0.0 0.1 0.2 0.3 0.4 0.5 0.60

2

4

6

8

10

12

C

urr

ent

den

sity

(m

A/c

m2 )

Potential (V)

P3HT PCPDTBT PCDTBT PTAA

3.0

4.0

5.0

6.0

FTO4.4

P3HT PCPDTBT PCDTBT PTAA

Au5.25.5

5.1

5.25.3TiO2

Bind

ing

ener

gy (

eV)

Sb2S3

= =EAc

PmaxEAc

FFIV

Nanostructured Sb2S3/various CPs heterojunction solar cells

16

001

010

100

= S

= Sb

Long Sb-S bond

Short Sb-S bond

Speculation: Bi-thiophen break the long Sb-S bond and form bidentate chelating bond to Sb

S SSb

S S

S

Toward bi-thiophene moiety in a CP

Efficient hole extraction

Nano Lett. 2011, 11, 4789–4793

9

17

Toward bi-thiophene moiety in a CP

Efficient hole extraction

Nano Lett. 2011, 11, 4789–4793

18

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

0

2

4

6

8

10

12

14

16

18

Jsc=1.7 mA/cm2, Voc=535 mV, FF=70.5%, =6.53%

Jsc=8.3 mA/cm2, Voc=585 mV, FF=68.0%, =6.57%

Jsc=15.3 mA/cm2, Voc=616 mV, FF=65.7%, =6.18%

Cu

rre

nt

de

ns

ity

(mA

/cm

2)

Voltage (V)

1 sun 0.5 sun 0.1 sun Dark

Nano Lett. 2011, 11, 4789–4793

J-V curves over a range of intensities

Sb2S3/PCPDTBT heterojunction solar cells

PCPDTBT

10

19

600 650 700 750 8000

10

20

30

40

P3HT/TiO2

Sb2S

3/TiO2

P3HT/Sb2S

3/TiO

2

Ph

oto

lum

ines

cen

ce (

a.u

)

Wavelength (nm)

• UV-visible absorption spectra • (wavelength of excitation light = 530 nm)

FTOTiO2

Sb2S3P3HT Au

e

h

(1)

(2)(3)

(1)

(2)

(3)

Nanostructured Sb2S3/P3HT heterojunction solar cells

X

400 500 600 700 8000

20

40

60

80

100

EQ

E (

%)

Wavelength (nm)

P3HT PCPDTBT

20

Panchromatic Photon-Harvesting by Hole-Conducting Materials

300 400 500 600 700 8000

20

40

60

80

EQ

E (

%)

Wavelength (nm)

T/S/P T/S/P-P

PCBM : [6,6]-phenyl-C61-butyric acid methyl ester

Nanostructured Sb2S3/P3HT(PCBM) heterojunction solar cells

11

21

300 400 500 600 700 800 9000

20

40

60

80

100

EQ

E (

%)

Wavelength (nm)

T/S/PCPDTBT-PCBM T/S/PCPDTBT

Nano Lett. 12, 1863 (2012)

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.70

5

10

15

20

Jsc

=16.0 mA/cm2,

Voc

=595 mV,

F.F=65.5%, = 6.3%

Cu

rre

nt

de

ns

ity

(mA

/cm

2)

Voltage (V)

1 sun dark

Panchromatic Photon-Harvesting by Hole-Conducting Materials

Nanostructured Sb2S3/PCPDTBT(PCBM) heterojunction solar cells

TiO2

Sb2S3 PCPDTBT

22

0.0 0.2 0.4 0.60

6

12

18

Cu

rren

t de

nsity

(m

A/c

m2 )

Voltage (V)

Light power

(mW cm-2)

JSC

(mA cm-2)

VOC

(mV)

FF

(%)

PCE

(%)

100

50

10

16.1

9.6

2.0

711.0

672.7

600.1

65.0

67.0

70.0

7.5

8.7

8.4

200 220 240 260 280 300 320 340-0.004

-0.003

-0.002

-0.001

0.000

0.001

TA sample Measure voltage -1.0 V -2.0 V

NoTA sample Measure voltage -1.0 V -2.0 V

DL

TS

Sp

ect

ra (

C/C

0)

Temperature (K)

A

Rate Winodws : 0.9242 Hz

Thioacetamidepost-surface-

treatment

C

S

H3C NH2

Adv. Func. Mater. 24, 3587 (2014)

Sb2S3-based inorganic-organic hybrid solar cells

Passivation after CDD

Champion device

12

23

0.0 0.1 0.2 0.30

4

8

12

16

20

24

Cu

rre

nt

de

nsi

ty (

mA

cm

-2)

Voltage (V)

PCE: 3.12 %

Cu-Sb-TU complex sol

Spin coating Thermal decomposition

Repetition

- 6

- 5

- 4

E r

elat

ive

to v

acuu

m (

eV)

TiO2

4.3 CuSbS2

(Eg: 1.5 eV)

3.85

5.35

PC

PD

TB

T

5.3

HTMLight

sensitizerPhoto-

electrode

Au

5.1

e-

e-

h+h+

mp-TiO2/CuSb2S2/PCPDTBT hybrid solar cells

Angew. Chem. Int. Ed. 54, 4005 (2015)

Process

24

Nature Materials 13, 837 (2014) doi:10.1038/nmat4079 Published online 21 August 2014

13

25

A perovskite structure is any material with the same type ofcrystal structure as calcium titanium oxide (CaTiO3), known asthe perovskite structure ABO3.

Named after Russian mineralogist L. A. Perovski.

Most widely studied oxide structure: ABO3

What is Perovskite?

26

A-cation 12-fold coordinatedM-cation, octahedrally coord.X-Halide

Perovskite structure=AMX3 Schematic of MX6 octahedra and the organic moiety of the basic AMX3perovskite unit cell and three-dimensional network formed by AMX3 perovskite unit cells.

J. of Nanoparticles, 2013, 531871 (2013)

Schematic of 2D, 1D, and 0D IO-hybrid derived from parent AMX3 type 3D IO-hybrid

Hybrid Perovskites

14

27

Replacing Dye with Perovskite: Current Perovskite Solar Cells are built upon the architectural basis for DSSCs pioneered by Grätzel(EPFL, Switzerland)

3.81 %

3.13 %

mp-CH3NH3PbI(Br)3/electrolyte (LiI(Br)/I(Br)2 in acetonitrile)

(a) IPCE spectra and (b) I-V action scharacteristic for mp-TiO2/CH3NH3PbBr3(solid line) and CH3NH3PbI3/TiO2 (dashed line) 6.5 % (N. G. Park et al., Nanoscale, 3, 4088−4093. 2011)

T. Miyasaka et al., J. Am. Chem. Soc. 131, 6050 (2009)

Perovskite-sensitized solar cells

Architectures

28H. Snaith et al., Science, 338, 643 (2012)Received 31 May 2012

Left: Schematic representation of full device structure, where the mesoporous oxide is either Al2O3 or anatase TiO2. Right: Cross-sectional SEM image of a full device incorporating mesoporous Al2O3. Scale bar, 500 nm. The construction of a planar-junction diode with the structure FTO/compact

TiO2/CH3NH3PbI2Cl/spiro-OMeTAD/Ag. spiro-OMeTAD: 2,2´,7,7´-tetrakis-(N,Ndi-p-methoxyphenylamine)9,9´-spirobifluorene

Replace Liquid Electrolyte with a Solid Hole Transporting Layer (HTL)

Perovskite-sensitized solar cells

Architectures

15

29

(a) Real solid-state device. (b) Cross-sectional structure of the device. (c) Crosssectional SEM image of the device. (d) Active layer-underlayer-FTO interfacial junction structureN.G. Park eta al., Sci. Report, 2, 591 (2012)Received 5 July 2012

Replace Liquid Electrolyte with a Solid Hole Transporting Layer (HTL)Perovskite-sensitized solar cells

Architectures

30

0.0 0.2 0.4 0.6 0.8 1.0 1.20

4

8

12

16

20

J (m

A/c

m2)

Voltage (V)

P3HT PCPDTBT PCDTBT PTAA Au

0.0 0.2 0.4 0.6 0.8 1.0

0

5

10

15

J (m

A/c

m2 )

Voltage (V)

Voc = 1.0 V Jsc = 16.5 mA/cm2

F.F = 72.7 % η = 12.0 %

6 7 8 9 10 11 12 130

5

10

15

20

25

30

35

Co

un

ts

(%)

Inorganic-organic hybrid perovskite solar cells

Nature Photonics, 7, 486 (2013)

Architectures: new era

16

31

SEM cross-sectional image SEM surface image

Dense nanocomposite and thin upper layers Is different with conventional dye-sensitized structure Perovskite CH3NH3PbI3 as both light harvester and hole conductor

Architectures

32

0 4000 8000 120000.0

0.5

1.0

Inte

nsi

ty (

a.u

)

Etching time (s)

Au4f Pb4f C1s N1s Ti2p Sn3d5 I3d5

700 750 800 850 9000.0

0.5

1.0

mp-TiO2/CH3NH3PbI

mp-TiO2/CH3NH3PbI3/PTAA

mp-Al2O3/CH3NH3PbI3

mp-Al2O3/CH3NH3PbI3/PTAA

Inte

nsi

ty (

a.u

)

Wavelength (nm)

XPS (X-ray photoelectron spectroscopy) depth profile

Photoluminescence (PL) spectra

Nature Photonics, 7, 486–491 (2013)

Architectures

17

33

A. Goossens et al., Nano Lett., 5, 1716–1719 (2005)

3D solar cells, with a remarkable energy conversion efficiency of 5%.

mp-TiO2/CIS/C

Architectures

34

Sargent et al., Nature Nanotechnology, 7, 577-582 (2012)

Schematic of the depleted heterojunctionCQD device

Cross-sectional SEM image of the same device

Sargent et al., ACS Nano, 4, 3374–3380 (2010)

Depleted-Heterojunction Colloidal QD Cells

Architectures

18

35

0.0 0.1 0.2 0.3 0.4 0.5 0.60

5

10

15

20

J (m

A/c

m2 )

Voltage (V)

CITSe-pristine CITSe-heat treated

400 600 800 10000

20

40

60

80

EQ

E (

%)

Wavelength (nm)

CITSe-pristine CITSe-heat treated

17.4 mA/cm2 of short circuit current density (Jsc), 0.40 V of open circuit voltage (Voc), 44.1% of fill factor (F.F) and 3.1 %

CITSeThe Cu:In:Te:Se precursor ratio of 1:1:1:2 resulted in Cu0.23In0.36Te0.19Se0.22 alloy QDs

mp-TiO2/CITSe/Au solar cells

ACS Nano, 7, 4756–4763 (2013)

36

3-D mp-TiO2/perovskite nanocomposite and thin film layer] pillared architecture, and new platform for efficient cells

Nature Photonics, 7, 486 (2013)

mp-TiO2/MAPbI3/PTAA hybrid solar cells

Architectures

19

37

Annealing at 100 oCc

Mixture of GBL/DMSO (MAI+PbI2, PbBr2)

With dripping tolueneW/O

a b

Pure GBL (MAI+PbI2, PbBr2)

WithW/O

Process for Bilayer architecture

Toluene dripping

Nature Materials, 13 (2014) 897

38

5 10 15 20 25 30 35 40

Inte

nsi

ty (

a.u

.)

CH3NH

3I-PbI

2-DMSO

PbI2(DMSO)

2

CH3NH

3I

2 theta (degree)

PbI2

a b

c

5 10 15 20 25

* Perovskite **

Inte

nsi

ty (

a.u

.)

*

130 oC

100 oC

RT

2theta (degree)

70 oC

4000 3500 3000 2500 2000 1500 1000 500

Tra

nsm

itta

nce

Wavenumber (cm-1)

C-N stretchC-H bend

S-O stretch

N-H stretchC-H stretch

N-H bend

a, XRD spectra of PbI2, MAI, PbI2(DMSO)2b, FTIR spectrum of PbI2-MAI-DMSO intermediate phasec, XRD spectra of PbI2-MAI-DMSO intermediate phase powder as a function of

temperature

Nature Materials, 13 (2014) 897

Process for Bilayer architecture

20

39

PbI2-Edge-sharing octahedrons layered structure.

MAPbI3 perovskites-Corner-sharing octahedrons -Perovskite structure

PbI2/MAI- Quick self-assemble

PbI2(MAI)(DMSO)-MAI and DMSO intercalation between layers.-Sequence of guest molecules is unconfirmed.

PbI2(MAI)-MAI intercalation into the PbI2 layered structure.-Imaginary structure.

GBL

-GBL

+MAI

+MAI

A plausible mechanism

or DMF

: MAI

Nature Materials, 13 (2014) 897

Process for Bilayer architecture

40

a

50 m

a b

500 nm

H. J. Snaith et al., Nature, 501, 395 (2013)

Solvent-engineeringprocess

Process for Bilayer architecture

21

41

Efficient planar heterojunction perovskite solar cells by vapourdeposition

H.J. Snaith et al., Nature, 2013, 501, 395–398

42

0 100 200 300 4006

8

10

12

14

16

18

20

Average

Reverse

Po

wer

co

nve

rsio

n e

ffic

ien

cy

(%

)

Thickness of mp-TiO2 (nm)

Forward

0

5

10

15

20

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.10

5

10

15

20

25

Forward

Cu

rren

t d

ensi

ty

︵mA

/cm

2

︶

Reverse

Forward

Voltage (V)

Reverse

a c

b

Photovoltaic performance as a function of scan direction and mp-TiO2 thickness layer.

Nature Materials, 13 (2014) 897

Hysteresis issue: Bilayer architecture

22

43

P-I-N

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90

5

10

15

20

25

reverse scan forward scan

Cu

rren

t d

ensi

ty (

mA

/cm

2 )

Voltage (V)

Scandirection

Jsc

(mAcm-2)Voc

(V)FF(%)

PCE(%)

reverse 19.6 0.846 78.1 12.9

forward 19.6 0.846 75.9 12.6

Glass

ITO

CH3 NH3 PbI3

PCBM

LiF(0.5nm)/A

l

PED

OT:P

SS

Architecture: bilayer structure (balancing between e and h)

N-I-P Depletion

thickness

Energy Environ. Sci., 2014, 7, 2642–2646

44

Band-gap tuning (MA=CH3NH3)

MAPbI3 MAPbBr3

a

b

c

-4.0E (e

V)

-5.44

-3.93MAPbI3

1.5 eV

-5.58

-3.36MAPbBr3

2.2 eV

PTAAAu

-5.2TiO2

Nano Lett. 13, 1764−1769 (2013)

Materials: CH3NH3Pb(I1-xBrx)3

23

45

0.0 0.2 0.4 0.6 0.8 1.0

2

4

6

8

10

12

Effic

ienc

y (%

)

x

500 600 700 800

Ab

sorban

ce

︵a.u.

︶

Wavelength ︵nm ︶

x=0

x=1.0

500 600 700 800

Absorban

ce

︵a.u.

︶

Wavelength ︵nm ︶

. . .

Materials: CH3NH3Pb(I1-xBrx)3

Nano Lett. 13, 1764−1769 (2013)

46

x = 0

x = 0.06

x = 0.29

x = 0.20

35 % 35 %55 % Humidity

0 2 4 6 8 10 12 14 16 18 20 222

3

4

5

6

7

8

9

10

11

12

Efficiency

︵%

︶

DaysNano Lett. 13, 1764−1769 (2013)

Materials: CH3NH3Pb(I1-xBrx)3

24

47

Materials: CH3NH3Pb(I1-xBrx)3

0 5 10 15 202

4

6

8

10

12

14

16

18

20

Scan rate=40ms, Humidity=25%

, y

Eff

icie

ncy

(%)

Days

MAPbI0.85

Br0.15

Reverse scan

MAPbI0.85

Br0.15

Foward scan

MAPbI3 Reverse scan

MAPbI3 Foward scan

48

N

N

N

N O

OO

O

O O

O O

Chemical Formula: C72H62N4O8

Exact Mass: 1110.46

AuHTM(

Compact layer

FTO

CH3NH3PbI3+mp TiO2

0.0 0.2 0.4 0.6 0.8 1.00

5

10

15

20

Cu

rre

nt

de

ns

ity

(mA

/cm

2)

Voltage (V)

spirobifluorene core in the spiro-OMeTAD Pyrene

J. Am. Chem. Soc., 135, 19087 (2013)

Materials: HTMs

25

49

0.0 0.2 0.4 0.6 0.8 1.00

5

10

15

20

Cur

rent

den

sity

︵mA

/cm

2

︶

Voltage (V)

Commercial pp pm po

J. Am. Chem. Soc., 136, 7837 (2014)

Jsc (mA/cm2) Voc (V) FF PCE (%)

merk(pp) Spiro

20.4 1.00 73.7 15.2

pm-Spiro 21.1 1.01 65.2 13.9

po-Spiro 21.2 1.02 77.6 16.7

pp-Spiro 20.7 1.00 71.1 14.9

TiO2

-5.44

-3.93-4.0

E (eV)

MAPbI3

-5.1

Au

-5.22eV -5.31eV -5.22eV

-2.28eV -2.31eV-2.18eV

pp pm po

1 µm

FTO

Materials: HTMs

50

0.0 0.5 1.0 1.5-20

-15

-10

-5

0

5

10

Voltage (V)

Jsc

(mA

/cm

2 )

MAPbBr3

PTAA PF8-TAA PIF8-TAA

-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4-60

-50

-40

-30

-20

-10

0

10

20

MAPbI3/PTAA

MAPbBr3/PTAA

J (m

A/c

m2)

Voltage (V)

PTAA 5.14 eV

5.68 eV5.46 eV

3.93 eV3.38 eV

MAPbI3

5.44 eV5.51 eV

PF8

PIF8

TiO2

4.0 eV

TiO2

4.0 eV

MAPbBr3

1.4V1.29V 1.04V

Energy & Environ Sci. 2014, 7, 2614–2618

Materials: HTMs

26

51

mp-TiO2/FAPbI3/PTAA hybrid solar cells

Materials: Phase stability

Photographs of inorganic-organic hybrid halide powders. Photographs show the color of the as-prepared MAPbI3, annealed FAPbI3 at 170 C, FAPbI3, (FAPbI3)1-x(MAPbI3)x, (FAPbI3)1-x(FAPbBr3)x, and (FAPbI3)1-x(MAPbBr3)x powders with x = 0.15 (from left to right). The (FAPbI3)1-x(MAPbBr3)x powder is the only black powder among the as-prepared FAPbI3-based materials

Nature, 517, 476–480 (2015)

52

10 15 20 25 30 35 40

Inte

nsi

ty (a.

u.)

2theta (degree)

As-prepared powder

170 oC-annealed powder

Powder after 10 days in air

Re-annealed powder

mp-TiO2/FAPbI3/PTAA hybrid solar cells

Materials: Phase stability

XRD spectra of FAPbI3 powders. The as-prepared yellow FAPbI3 powder shows a non-perovskite phase and is converted to perovskite phase by annealing at 170 C. The perovskite FAPbI3 black powder returned to the yellow non-perovskite powder after being stored in air for 10 h; the yellow powder reversibly changed to black perovskite phase by re-annealing at 170 C.

Nature, 517, 476–480 (2015)

27

53Nature, 517, 476–480 (2015)

mp-TiO2/FAPbI3/PTAA hybrid solar cells

10 15 20 25 30 35 40

##

Inte

nsity

(a.u

.)

#

2theta

0.0 0.1 0.2 0.3 0.41

2

3

4

5

0.6

0.5

0.4

0.3

0.2

0.1

Rec

ipro

cal o

f F

WH

M

FW

HM

of

(-11

1) p

eak

x

5 μm

x = 0

x = 0.05

x = 0.15

FAPbI3

(FAPbI3)1-x(FAPbBr3)x

(FAPbI3)1-x(MAPbI3)x

(FAPbI3)1-x(MAPbBr3)xX=0.15

Materials: Phase & morphology

54

10 15 20 25 30 35 40

Inte

ns

ity

(a

.u.)

x=0.30

x=0.15

x=0.10

2theta

x=0.05

#: FTO

##

#

Materials: (FAPbI3)1-x(MAPbBr3)x

mp-TiO2/(FAPbI3)0.85(MAPbBr3)0.15/PTAA

28

55

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.202468

1012141618202224

Cu

rren

t de

nsi

ty

︵mA

/cm

2

︶

Voltage (V)300 400 500 600 700 8000

20

40

60

80

100

Wavelength (nm)

EQ

E (

%)

0

4

8

12

16

20

24

Inte

rgra

ted

Jsc

(m

A/c

m2 )

Jsc (mA/cm2)

Voc (V)

FF(%)

η(%)

22.5 1.11 73.2 18.4

J-V and IPCE characteristics for the best cell obtained in (FAPbI3)0.85(MAPbBr3)0.15

Nature, 517, 476–480 (2015)

mp-TiO2/(FAPbI3)0.85(MAPbBr3)0.15/PTAA

56

Summary

We sucessfully demonstrated efficient inorganic-organic hybrid solar cells antimony chalcogenides andperovskites as light harvesters.

The hysteresis effect can be inhibited or eveneliminated by using FAPbI3 for N-I-P, and MAPbI3 for P-I-N structure, respectively.

The architecture, process, and composition for lightharvesters should be optimized to fabricate furtherefficient solar cells