2013년 제4회 태양광기술 지식연구회 - 나노구조 무/유기 하이브리드 태양전지 = Nanostructured inorganic-organic hybrid solar cells -

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1 KRICT-EPFL Global Research Lab.

Solar Energy Harvesting Systems Lab.

나노구조 무/유기 하이브리드 태양전지

(Nanostructured inorganic-organic hybrid solar cells)

28 October, 2013

석상일

한국화학연구원 광에너지 융합소재 연구그룹

([email protected])

KRICT-EPFL Global Research Lab.

Outline

 State-of-art of solar cells

 Research scheme: Why nanostructured inorganic-organic hybrid

solar cells?

 Efficient inorganic-organic heterojunction hybrid solar cells

 Sb

2

S

3

/P3HT, Sb

2

S

3

/PCPDTBT system

 CH

3

NH

3

Pb(I

1-x

Br

x

)

3

(x=0 ~1)/PTAA system

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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

Hybrid solar cells (Nano-oxide and polymer) I

II

III Inorganic-organic

Hybrid Heterojunction solar cells Organic solar cells

(Tandem cells)

State-of-the- Art of Solar cells

Our research area

Strategies: Integration of nanostructured architecture, and

solution-processable organic/inorganic materials and new light

harvesters that have high absorption-coefficient

Research scheme

Innovative Inorganic-Organic Hybrid Solar Cells

Hole conducting organic materials (low-fabrication cost by

solution-process:)

Nanostructured inorganic architecture (long-term stability by robust

structure) Quantum effects

DSSCs

OPVs

I/O interface control New light harvesters (High-efficiency)

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20 30 40 50 60 70 80 0 100 200 300 400 500 600 In te nsity (a rb. uni t) 2 theta (deg) Sb 2S3 CBD on Glass PDF 042-1393 Stibnite FTO coated substrate CBD Process

XRD pattern of Sb2S3annealed at ~300 oC after CBD

Sb₂S₃

TiO2

Precursors: SbCl3and Sodium thiosulfate

Sb

2

S

3

/P3HT heterojunction solar cells

Sb₂S₃: a high absorption coefficient (1.8 × 105_cm–1_at

450 nm) and optimum

bandgap (E_g= 1.7 eV)

0.0 0.2 0.4 0.6 0 5 10 15 1 h 2 h 3 h 4 h C u rr ent densi ty ( m A cm -2) Potential (V) mp-TiO₂/P3HT/Au 400 500 600 700 800 0 20 40 60 80 IP C 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 0.092 1 5.3 424 64.1 1.48 2 9.1 465 65.5 2.92 3 12.3 556 69.9 5.06 4 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

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Stability with time

0 200 400 600 800 10 12 14 500 600 700 60 70 80 4 5 6 Js c ( mA c m -2 ) Time (hours) Voc ( m V) FF (% ) Eff. (%) Time [hours] [mA/ cmJsc 2_] Voc [mV] [%]Ff [%]Eff. 0 12.3 556 69.7 5.09 72 12.3 556 69.9 5.09 216 12.1 566 69.4 5.09 360 12.2 556 68.1 4.88 576 12.1 566 64.1 4.66 720 11.8 576 66.5 4.77 0.0 0.2 0.4 0.6 -5 0 5 10 15 P hotocur rent de nsity ( mA/cm 2) Voltage(V) 0 day 30 days Reproducibility: OK !

Nanostructured Sb

2

S

3

/P3HT heterojunction solar cells

KRICT-EPFL Global Research Lab. 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% C u rr e 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-Vcurves over a range of intensities IPCE

Sb

2

S

3

/PCPDTBT heterojunction solar cells

400 500 600 700 800 0 20 40 60 80 100 EQE (%) Wavelength (nm) P3HT PCPDTBT

PCPDTBT

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Panchromatic Photon-Harvesting by Hole-Conducting Materials

300

400

500

600

700

800

0

20

40

60

80 EQE (%

)

Wavelength (nm)

T/S/P

T/S/P-P

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

Sb

2

S

3

/P3HT(PCBM) heterojunction solar cells

300 400 500 600 700 800 900 0 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 0.7 0 5 10 15 20 J sc=16.0 mA/cm 2 , V_oc=595 mV, F.F=65.5%,  = 6.3% C u rr e n t de ns it y ( mA /c m 2 ) Voltage (V) 1 sun dark

Panchromatic Photon-Harvesting by Hole-Conducting Materials

Sb

₂

S

₃

/PCPDTBT(PCBM) heterojunction solar cells

TiO₂

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Solar Energy Harvesting Systems Lab. TiO2 (3.2) Sb2S3 (1.7) Sb2Se3 (1.1) e- e -h+ h+ h+ e -P3HT TiO2 (3.2) h+ P3HT Sb2Se3 Sb2S3 h+ h+ e -e -e -Cascaded band alignment Light power (mW cm-2₎ Jsc (mA cm-2 ) Voc (mV) FF (%) PCE (%) 100 50 10 24.9 14.6 3.0 474.8 424.6 364.3 55.6 60.2 62.3 6.6 7.5 6.8 14 15 16 17 18 19 S/T S/Se/T Se/T In te n s it y ( a .u .) 2 (degree) (020) (120) (020) (120)

Sb

₂

(S/Se)

₃

-/P3HT Heterojunction Solar Cells with Graded Composition

In Review(2013)

KRICT-EPFL Global Research Lab. (b)

Sb

₂

S

₃

/P3HT Heterojunction Solar Cells

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 In Review(2013)

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[PbX₆] octahetra form an extended 3D network by all-corner-connected type

CH₃NH₃I PbI₂ in ɤ-butyrolactone CH3NH3PbI3solution 10 20 30 40 50 60 0.0 0.2 0.4 0.6 0.8 1.0 In tensity ( a .u ) 2 (degree) 0 100 200 300 400 500 0 20 40 60 80 100 120 Weight Derivertive weight Temperature (o_C) W e igh t ( % ) 0 2 4 6 8 10 D e ri v . W e igh t ( % /_o C) 26 %

Nanocrystalline MAPbX

3

/

PTAA

heterojunction solar cells

Perovskite/PTAA heterojunction solar cells

SEM cross-sectional image

SEM surface image

 Dense nanocomposite and thin upper layers

 Is different with conventional dye-sensitized structure

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Efficient planar heterojunction perovskite solar cells by vapour

deposition

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

3-D mp-TiO

₂

/perovskite nanocomposite and thin film layer]



New platform

Perovskite/PTAA heterojunction solar cells

Nature Photonics, 7, 486 (2013)

 Dense nanocomposite and thin upper layers

 Operate differently with conventional DSSC

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Band-gap tuning (MA=CH₃NH₃)

MAPbI3 MAPbBr3 a b c -4.0 E (eV) -5.44 -3.93 MAPbI3 1.5 eV -5.58 -3.36 MAPbBr3 2.2 eV PTAAAu -5.2 TiO2 Nano Lett. 13, 1764−1769 (2013)

Chemical Management of Perovskite CH

3

NH

3

Pb

(I

1-x

Br

x

)

3

A least-squares fit: small bowing parameter (b=0.33eV) a great miscibility

Chemical Management of Perovskite CH

3

NH

3

Pb

(I

1-x

Br

x

)

3

5 0 0 6 0 0 7 0 0 8 0 0 A b s o r b a n c e︵ a . u .︶ W a v e l e n g t h ︵n m ︶ x=0 x=1.0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1 . 0 1 . 5 1 . 6 1 . 7 1 . 8 1 . 9 2 . 0 2 . 1 2 . 2 2 . 3 E︵g e V︶ x E_g(x) = 1.57 + 0.39x+ 0.33x2 E_g[MAPb(I1-xBrx)3] = Eg[MAPbI3] + (E_g[MAPbBr₃] – E_g[MAPbI₃] –b)

x

+ b

x

2 Nano Lett. 13, 1764−1769 (2013)

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x = 0

x = 0.06

x = 0.29

x = 0.20

35 %

55 %

35 %

Humidity

0 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 3 4 5 6 7 8 9 1 0 1 1 1 2

E

f

i

c

i

e

n

c

y︵

%︶

D a y s

Chemical Management of Perovskite CH

3

NH

3

Pb

(I

1-x

Br

x

)

3

Nano Lett. 13, 1764−1769 (2013)