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Page 1: SUPPLEMENTARY INFORMATION - berkeleyresearch.physics.berkeley.edu/zettl/pdf/nmat4795-s1.pdfSUPPLEMENTARY INFORMATION. DOI: 10.1038/NMAT4795. NATURE MATERIALS | . 1. 1 Graded band gap

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1

Graded band gap perovskite solar cells

Supplementary Information

Onur Ergen, 1,3,4 S.Matt Gilbert1, 3,4, ,Thang Pham1, 3,4 ,Sally J. Turner, 1,2,4, Mark Tian Zhi Tan 1, Marcus A. Worsley5 and Alex Zettl1, 3,4 1Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA 2Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, USA 3Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA 4Kavli Energy Nanosciences Institute at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA 5 Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA Corresponding Author: Prof. Alex Zettl ([email protected]) Supporting Information Content

A) Material Characterization

• Absorption and Photoluminescence measurements • SEM-EDAX study • Top view SEM Images • XRD patterns

B) Electrical Characterization

• Current density vs. Time • Hall Effect mobility measurements • I-V curve of champion cell • The reverse and forward sweep of perovskite cells • Ohmic contact behavior of GaN • NIR-PL spectra of graded band gap perovskite cells • MASnI3 based solar cell with only GA modification • EQE&IQE data of champion cell with integrated photocurrent • Back surface pits on the GaN suface • Mott-Schottky measurements GaN/Perovskite interface

1

Graded bandgap perovskite solar cells

Supplementary Information

Onur Ergen, 1,3,4 S.Matt Gilbert1, 3,4, ,Thang Pham1, 3,4 ,Sally J. Turner, 1,2,4, Mark Tian Zhi Tan 1, Marcus A. Worsley5 and Alex Zettl1, 3,4 1Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA 2Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, USA 3Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA 4Kavli Energy Nanosciences Institute at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA 5 Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA

Corresponding Author:

Prof. Alex Zettl ([email protected])

Supporting Information Content

A) Material Characterization

• Absorption and Photoluminescence measurements• SEM-EDAX study• Top view SEM Images• XRD patterns

B) Electrical Characterization• Current density vs. Time• Hall Effect mobility measurements• I-V curve of champion cell• The reverse and forward sweep of perovskite cells• Ohmic contact behavior of GaN• NIR-PL spectra of graded band gap perovskite cells• MASnI3 based solar cell with only GA modification• EQE&IQE data of champion cell with integrated photocurrent• Back surface pits on the GaN suface• Mott-Schottky measurements GaN/Perovskite interface

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A) MaterialCharacterization

Concentration variation

Figure S 1 (a) UV-visible light absorption spectra of CH3NH3SnI3-xBrx and CH3NH3Pb(I1-xBrx)3, with varying iodide concentration “x”, b) Photoluminescence (PL), spectra of perovskite cells, CH3NH3SnI3-x and CH3NH3Pb(I1-xBrx)3, by varying iodide concentration “x”. The role of the graphene aerogels

500 600 700 800 900 1000 1100

Abs

orba

nce

(a.u

.)

Wavelength (nm)

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300 400 500 600 700 800 900 1000 1100 1200

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3

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Phot

olum

ines

cenc

e (a

.u.)

Wavelength (nm)

x=1 x=0

x=1 x=0

(a)

(b)

CH3NH3Pb(I1-xBrx)3, x=0 CH3NH3Pb(I1-xBrx)3, x=0.045

CH3NH3Pb(I1-xBrx)3, x=1

CH3NH3Pb(I1-xBrx)3, x=0.5CH3NH3Pb(I1-xBrx)3, x=0.65

CH3NH3Sn(I3-x)Brx, x=1CH3NH3Sn(I3-x)Brx, x=0

CH3NH3Pb(I1-xBrx)3, x=0 CH3NH3Pb(I1-xBrx)3, x=0.045

CH3NH3Pb(I1-xBrx)3, x=1

CH3NH3Pb(I1-xBrx)3, x=0.5CH3NH3Pb(I1-xBrx)3, x=0.65

CH3NH3Sn(I3-x)Brx, x=1CH3NH3Sn(I3-x)Brx, x=0

2

A) MaterialCharacterization

Concentration variation

Figure S 1 (a) UV-visible light absorption spectra of CH3NH3SnI3-xBrx and CH3NH3Pb(I1-xBrx)3, with varying iodide concentration “x”, b) Photoluminescence (PL), spectra of perovskite cells, CH3NH3SnI3-x and CH3NH3Pb(I1-xBrx)3, by varying iodide concentration “x”. The role of the graphene aerogels

500 600 700 800 900 1000 1100

Abs

orba

nce

(a.u

.)

Wavelength (nm)

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300 400 500 600 700 800 900 1000 1100 1200

5

3

7

Phot

olum

ines

cenc

e (a

.u.)

Wavelength (nm)

x=1 x=0

x=1 x=0

(a)

(b)

CH3NH3Pb(I1-xBrx)3, x=0 CH3NH3Pb(I1-xBrx)3, x=0.045

CH3NH3Pb(I1-xBrx)3, x=1

CH3NH3Pb(I1-xBrx)3, x=0.5CH3NH3Pb(I1-xBrx)3, x=0.65

CH3NH3Sn(I3-x)Brx, x=1CH3NH3Sn(I3-x)Brx, x=0

CH3NH3Pb(I1-xBrx)3, x=0 CH3NH3Pb(I1-xBrx)3, x=0.045

CH3NH3Pb(I1-xBrx)3, x=1

CH3NH3Pb(I1-xBrx)3, x=0.5CH3NH3Pb(I1-xBrx)3, x=0.65

CH3NH3Sn(I3-x)Brx, x=1CH3NH3Sn(I3-x)Brx, x=0

3

(a) (b)

(a) (b)

(c) (d)

Figure S 2 Photoluminescence analysis of perovskite cells in air (only CH3NH3PbI3-xBrx ). (a) without GA. (b) with GA modification. (c) Bandgap changing by time with and without GA layer. (d) EDAX line mapping for oxygen signature of a perovskite with and without GA modification. Graphene aerogel encapsulation acts as a barrier for oxygen penetration and moisture ingress.

3

(a) (b)

(a) (b)

(c) (d)

Figure S 2 Photoluminescence analysis of perovskite cells in air (only CH3NH3PbI3-xBrx ). (a) without GA. (b) with GA modification. (c) Bandgap changing by time with and without GA layer. (d) EDAX line mapping for oxygen signature of a perovskite with and without GA modification. Graphene aerogel encapsulation acts as a barrier for oxygen penetration and moisture ingress.

3

(a) (b)

(a) (b)

(c) (d)

Figure S 2 Photoluminescence analysis of perovskite cells in air (only CH3NH3PbI3-xBrx ). (a) without GA. (b) with GA modification. (c) Bandgap changing by time with and without GA layer. (d) EDAX line mapping for oxygen signature of a perovskite with and without GA modification. Graphene aerogel encapsulation acts as a barrier for oxygen penetration and moisture ingress.

4

The role of the h-BN

Figure S 3(a) Top view SEM image of a perovskite sample after peeling off GA layer. The line formations arise due to interfacial adhesion. (b) Top view SEM image of samples without GA improvement. The scale bars in the SEM images are 5µm.

Figure S 4 XRD diffraction patterns of the perovskite layers of a) W/ GA and b) W/O GA.

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5

3

7

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nsity

(a.

u.)

1

10 20 30 40 50 60

5

3

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10 25 40 60

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(a.

u.)

2θ (degree)

2θ (degree)

(b)

(a)

W/ GA

W/O GA

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A) MaterialCharacterization

Concentration variation

Figure S 1 (a) UV-visible light absorption spectra of CH3NH3SnI3-xBrx and CH3NH3Pb(I1-xBrx)3, with varying iodide concentration “x”, b) Photoluminescence (PL), spectra of perovskite cells, CH3NH3SnI3-x and CH3NH3Pb(I1-xBrx)3, by varying iodide concentration “x”. The role of the graphene aerogels

500 600 700 800 900 1000 1100

Abs

orba

nce

(a.u

.)

Wavelength (nm)

1

300 400 500 600 700 800 900 1000 1100 1200

5

3

7

Phot

olum

ines

cenc

e (a

.u.)

Wavelength (nm)

x=1 x=0

x=1 x=0

(a)

(b)

CH3NH3Pb(I1-xBrx)3, x=0 CH3NH3Pb(I1-xBrx)3, x=0.045

CH3NH3Pb(I1-xBrx)3, x=1

CH3NH3Pb(I1-xBrx)3, x=0.5CH3NH3Pb(I1-xBrx)3, x=0.65

CH3NH3Sn(I3-x)Brx, x=1CH3NH3Sn(I3-x)Brx, x=0

CH3NH3Pb(I1-xBrx)3, x=0 CH3NH3Pb(I1-xBrx)3, x=0.045

CH3NH3Pb(I1-xBrx)3, x=1

CH3NH3Pb(I1-xBrx)3, x=0.5CH3NH3Pb(I1-xBrx)3, x=0.65

CH3NH3Sn(I3-x)Brx, x=1CH3NH3Sn(I3-x)Brx, x=0

2

A) MaterialCharacterization

Concentration variation

Figure S 1 (a) UV-visible light absorption spectra of CH3NH3SnI3-xBrx and CH3NH3Pb(I1-xBrx)3, with varying iodide concentration “x”, b) Photoluminescence (PL), spectra of perovskite cells, CH3NH3SnI3-x and CH3NH3Pb(I1-xBrx)3, by varying iodide concentration “x”. The role of the graphene aerogels

500 600 700 800 900 1000 1100

Abs

orba

nce

(a.u

.)

Wavelength (nm)

1

300 400 500 600 700 800 900 1000 1100 1200

5

3

7

Phot

olum

ines

cenc

e (a

.u.)

Wavelength (nm)

x=1 x=0

x=1 x=0

(a)

(b)

CH3NH3Pb(I1-xBrx)3, x=0 CH3NH3Pb(I1-xBrx)3, x=0.045

CH3NH3Pb(I1-xBrx)3, x=1

CH3NH3Pb(I1-xBrx)3, x=0.5CH3NH3Pb(I1-xBrx)3, x=0.65

CH3NH3Sn(I3-x)Brx, x=1CH3NH3Sn(I3-x)Brx, x=0

CH3NH3Pb(I1-xBrx)3, x=0 CH3NH3Pb(I1-xBrx)3, x=0.045

CH3NH3Pb(I1-xBrx)3, x=1

CH3NH3Pb(I1-xBrx)3, x=0.5CH3NH3Pb(I1-xBrx)3, x=0.65

CH3NH3Sn(I3-x)Brx, x=1CH3NH3Sn(I3-x)Brx, x=0

3

(a) (b)

(a) (b)

(c) (d)

Figure S 2 Photoluminescence analysis of perovskite cells in air (only CH3NH3PbI3-xBrx ). (a) without GA. (b) with GA modification. (c) Bandgap changing by time with and without GA layer. (d) EDAX line mapping for oxygen signature of a perovskite with and without GA modification. Graphene aerogel encapsulation acts as a barrier for oxygen penetration and moisture ingress.

3

(a) (b)

(a) (b)

(c) (d)

Figure S 2 Photoluminescence analysis of perovskite cells in air (only CH3NH3PbI3-xBrx ). (a) without GA. (b) with GA modification. (c) Bandgap changing by time with and without GA layer. (d) EDAX line mapping for oxygen signature of a perovskite with and without GA modification. Graphene aerogel encapsulation acts as a barrier for oxygen penetration and moisture ingress.

3

(a) (b)

(a) (b)

(c) (d)

Figure S 2 Photoluminescence analysis of perovskite cells in air (only CH3NH3PbI3-xBrx ). (a) without GA. (b) with GA modification. (c) Bandgap changing by time with and without GA layer. (d) EDAX line mapping for oxygen signature of a perovskite with and without GA modification. Graphene aerogel encapsulation acts as a barrier for oxygen penetration and moisture ingress.

3

(a) (b)

(a) (b)

(c) (d)

Figure S 2 Photoluminescence analysis of perovskite cells in air (only CH3NH3PbI3-xBrx ). (a) without GA. (b) with GA modification. (c) Bandgap changing by time with and without GA layer. (d) EDAX line mapping for oxygen signature of a perovskite with and without GA modification. Graphene aerogel encapsulation acts as a barrier for oxygen penetration and moisture ingress.

3

(a) (b)

(a) (b)

(c) (d)

Figure S 2 Photoluminescence analysis of perovskite cells in air (only CH3NH3PbI3-xBrx ). (a) without GA. (b) with GA modification. (c) Bandgap changing by time with and without GA layer. (d) EDAX line mapping for oxygen signature of a perovskite with and without GA modification. Graphene aerogel encapsulation acts as a barrier for oxygen penetration and moisture ingress.

4

The role of the h-BN

Figure S 3(a) Top view SEM image of a perovskite sample after peeling off GA layer. The line formations arise due to interfacial adhesion. (b) Top view SEM image of samples without GA improvement. The scale bars in the SEM images are 5µm.

Figure S 4 XRD diffraction patterns of the perovskite layers of a) W/ GA and b) W/O GA.

1

5

3

7

Inte

nsity

(a.

u.)

1

10 20 30 40 50 60

5

3

7

10 25 40 60

Inte

nsity

(a.

u.)

2θ (degree)

2θ (degree)

(b)

(a)

W/ GA

W/O GA

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The role of the h-BN

Figure S 3(a) Top view SEM image of a perovskite sample after peeling off GA layer. The line formations arise due to interfacial adhesion. (b) Top view SEM image of samples without GA improvement. The scale bars in the SEM images are 5µm.

Figure S 4 XRD diffraction patterns of the perovskite layers of a) W/ GA and b) W/O GA.

1

5

3

7

Inte

nsity

(a.

u.)

1

10 20 30 40 50 60

5

3

7

10 25 40 60

Inte

nsity

(a.

u.)

2θ (degree)

2θ (degree)

(b)

(a)

W/ GA

W/O GA

4

The role of the h-BN

Figure S 3(a) Top view SEM image of a perovskite sample after peeling off GA layer. The line formations arise due to interfacial adhesion. (b) Top view SEM image of samples without GA improvement. The scale bars in the SEM images are 5µm.

Figure S 4 XRD diffraction patterns of the perovskite layers of a) W/ GA and b) W/O GA.

1

5

3

7 In

tens

ity (

a.u.

)

1

10 20 30 40 50 60

5

3

7

10 25 40 60

Inte

nsity

(a.

u.)

2θ (degree)

2θ (degree)

(b)

(a)

W/ GA

W/O GA

5

Figure S 5 Cross sectional SEM-EDAX analysis of perovskite cells (a) EDAX signal for cell with h-BN, over the area outlined by red box in the inset SEM image. (b) Line mapping of cell with h-BN modification (dashed line indicates the position of h-BN). The scan is along the vertical red line (from top to bottom) shown in the inset SEM image. (c) Line mapping of cell without h-BN modification. The scan is along the red vertical line (from top to bottom) shown in the inset SEM image. Scale bar for inset of a) and b) is 200nm; scale bar for inset of c) is 100nm.

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The role of the h-BN

Figure S 3(a) Top view SEM image of a perovskite sample after peeling off GA layer. The line formations arise due to interfacial adhesion. (b) Top view SEM image of samples without GA improvement. The scale bars in the SEM images are 5µm.

Figure S 4 XRD diffraction patterns of the perovskite layers of a) W/ GA and b) W/O GA.

1

5

3

7

Inte

nsity

(a.

u.)

1

10 20 30 40 50 60

5

3

7

10 25 40 60

Inte

nsity

(a.

u.)

2θ (degree)

2θ (degree)

(b)

(a)

W/ GA

W/O GA

4

The role of the h-BN

Figure S 3(a) Top view SEM image of a perovskite sample after peeling off GA layer. The line formations arise due to interfacial adhesion. (b) Top view SEM image of samples without GA improvement. The scale bars in the SEM images are 5µm.

Figure S 4 XRD diffraction patterns of the perovskite layers of a) W/ GA and b) W/O GA.

1

5

3

7

Inte

nsity

(a.

u.)

1

10 20 30 40 50 60

5

3

7

10 25 40 60

Inte

nsity

(a.

u.)

2θ (degree)

2θ (degree)

(b)

(a)

W/ GA

W/O GA

5

Figure S 5 Cross sectional SEM-EDAX analysis of perovskite cells (a) EDAX signal for cell with h-BN, over the area outlined by red box in the inset SEM image. (b) Line mapping of cell with h-BN modification (dashed line indicates the position of h-BN). The scan is along the vertical red line (from top to bottom) shown in the inset SEM image. (c) Line mapping of cell without h-BN modification. The scan is along the red vertical line (from top to bottom) shown in the inset SEM image. Scale bar for inset of a) and b) is 200nm; scale bar for inset of c) is 100nm.

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B) Electrical Characterization Stability under illumination

Figure S 6 a) Time dependent Current density (solid lines) and Voc (dashed lines) is shown. The cells without h-BN and GA exhibit faster degradation under constant illumination compared to the complete cell with h-BN and GA. (solid lines is Jsc and dashed lines is Voc ) b) Power conversion efficiency of the cells with h-BN and GA (red), cell w/h-BN and W/O GA (black), W/O h-BN and W/O GA (green). Complete cells show a very stable behavior under constant illumination. Even though a decrease was observed in the current density, there is a constant increase in open circuit voltage indicating that efficiency becomes stable with time.

Complete cell (W/h-BN, W/GA)

W/h-BN, W/O GA

W/O h-BN, W/O GA

10 20 30 40 50 60 70 80 90

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20

30

40

Time (min)

Curr

ent D

ensit

y (m

A/cm

2 )

10 20 30 40 50 60 70 80 90

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PCE

(%)

17

16

15

14

22

20

0.2

0.4

Ope

n Ci

rcui

t Vo

ltage

(V

)

0.8

0.6

(a)

(b)

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The role of the graphene aerogels on mobility

Figure S 7 Hall effect measurement. The mobility plotted against the annealing temperature of double layered perovskite cells (re-crystallization temperatures).

20 30 40 50 60 70 80 90 100

50

100

150

200

300

Crystallization Temperature (0C)

Hal

l Mob

ility

(cm

2 V-1

s-1)

Complete cell

Complete cell (W/O GA)

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B) Electrical Characterization Stability under illumination

Figure S 6 a) Time dependent Current density (solid lines) and Voc (dashed lines) is shown. The cells without h-BN and GA exhibit faster degradation under constant illumination compared to the complete cell with h-BN and GA. (solid lines is Jsc and dashed lines is Voc ) b) Power conversion efficiency of the cells with h-BN and GA (red), cell w/h-BN and W/O GA (black), W/O h-BN and W/O GA (green). Complete cells show a very stable behavior under constant illumination. Even though a decrease was observed in the current density, there is a constant increase in open circuit voltage indicating that efficiency becomes stable with time.

Complete cell (W/h-BN, W/GA)

W/h-BN, W/O GA

W/O h-BN, W/O GA

10 20 30 40 50 60 70 80 90

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20

30

40

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Curr

ent D

ensit

y (m

A/cm

2 )

10 20 30 40 50 60 70 80 90

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PCE

(%)

17

16

15

14

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20

0.2

0.4

Ope

n Ci

rcui

t Vo

ltage

(V

)

0.8

0.6

(a)

(b)

7

The role of the graphene aerogels on mobility

Figure S 7 Hall effect measurement. The mobility plotted against the annealing temperature of double layered perovskite cells (re-crystallization temperatures).

20 30 40 50 60 70 80 90 100

50

100

150

200

300

Crystallization Temperature (0C)

Hal

l Mob

ility

(cm

2 V-1

s-1)

Complete cell

Complete cell (W/O GA)

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Figure S 8 J-V curves for 21.7% PCE graded band gap perovskite cell with (red) and without (blue) light illumination.

9

Figure S 9 (a) Reverse and forward sweep (<0.01V/s) J-V for a typical graded band gap perovskite device. (b) Histogram of solar cell efficiencies with reverse and forward sweep, after 1h illumination in air.

(a) 45

40

30

25

35

Curre

nt D

ensit

y (m

A/c

m2 )

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Forward

Reverse

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nts

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R

R

R

R

R

PCE (%)

R

(b)

F F

F

F

F

F

F

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Figure S 8 J-V curves for 21.7% PCE graded band gap perovskite cell with (red) and without (blue) light illumination.

9

Figure S 9 (a) Reverse and forward sweep (<0.01V/s) J-V for a typical graded band gap perovskite device. (b) Histogram of solar cell efficiencies with reverse and forward sweep, after 1h illumination in air.

(a) 45

40

30

25

35

Curre

nt D

ensit

y (m

A/c

m2 )

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

10

5

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Forward

Reverse

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16

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nts

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R

R

R

R

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R

(b)

F F

F

F

F

F

F

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Figure S 10 Ohmic contact behavior illustrated by current-voltage (I-V) plots. The GaN contact paths are made from Ti/Al/Ni/Au (30/100/20/150 nm).

11

Figure S 11 Near infrared photoluminescence (NIR-PL) spectra of graded band gap perovskite solar cells, with both h-BN and GA modifications. Under constant illumination an additional PL peak forms near 1300nm and grows with increasing light intensity.

1

1000 1200 1400 1600

5

3

7

Phot

olum

ines

cenc

e (a

.u.)

Wavelength (nm)

Pre Illumination Post Illumination (15mWcm-2) Post Illumination (60mWcm-2) Post Illumination (100mWcm-2)

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© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.

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10

Figure S 10 Ohmic contact behavior illustrated by current-voltage (I-V) plots. The GaN contact paths are made from Ti/Al/Ni/Au (30/100/20/150 nm).

11

Figure S 11 Near infrared photoluminescence (NIR-PL) spectra of graded band gap perovskite solar cells, with both h-BN and GA modifications. Under constant illumination an additional PL peak forms near 1300nm and grows with increasing light intensity.

1

1000 1200 1400 1600

5

3

7

Phot

olum

ines

cenc

e (a

.u.)

Wavelength (nm)

Pre Illumination Post Illumination (15mWcm-2) Post Illumination (60mWcm-2) Post Illumination (100mWcm-2)

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© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.

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Figure S 12 (a) J-V measurement of MASnI3 based solar cells with and without GA. Devices prepared with GA show better stability in air. (All devices prepared in air). (b) J-V measurement of MASnI3 based devices which are fabricated by following the same procedures as shown in refs. [5] and [13], Type I and Type II respectively. Type I and Type II cells have the similar architecture (FTO/d-TiO2/mp-TiO2/MASnI3/spiro-OMETAD/Au), but different ETL, HTL and Au thicknesses. The table shows the detailed comparison of our cells prepared and cells reported in the literature.

Name Jsc (mA/cm2)

Voc (V)

FF (%)

PCE (%)

Type I-(Ref.5) 16.8 0.88 42 6.4 Type II- (Ref. 13) 12.30 0.82 57 5.73 Type I-(This work) 13.40 0.79 52 5.49 Type II-(This work) 15.9 0.69 49 5.36

(a)

(b)

0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

20

10

Cur

rent

Den

sity

(m

A/c

m2 )

Voltage (V)

Type I-MASnI3-(Ref.5) Type I-MASnI3-(This work) Type II-MASnIBr2-(Ref.13) Type II-MASnIBr2-(This Work)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

20

15

5

10

Curre

nt D

ensit

y (m

A/c

m2 )

Voltage (V)

MASnI3/GA (150nm thick MASnI3) (Freshly illuminated) MASnI3/GA(150nm thick MASnI3) (Under illumination 10min) MASnI3/GA (300nm thick MASnI3) (Under illumination 10min)

MASnI3/GA (300nm thick MASnI3) (Freshly iluminated)

GaN

MASnI3

GA/HTMBack Contact

GaN

MASnI3

HTMBack Contact

MASnI3 (Freshly iluminated cell) MASnI3 (Under illumination 10min)

13

Figure S 13 (a) External quantum efficiency of the champion cell with integrated photocurrent (thick black line). Maximum possible Jsc, if the QE is 100% over the spectrum, is 49.4mA/cm2 and the expected Jsc is 42.32mA/cm2. The EQE spectrum for reference silicon cells is also shown under A.M 1.5. (b) The plot of reflective absorbtion and internal quantum efficiency (IQE) versus wavelength. The inset shows the composition profile and approximate band diagram of the cell.

The integrated current Density(Jsc) = 42.33 mA/cm2 Max possible Jsc with 100% absorption= 49.44 mA/cm2

!

"!

#!

$!

%!

&!

'!

(!

)!

*!

"!!

$!! &!! (!! *!! ""!! "$!! "&!! "(!! "*!!

100

80

60

40

20

300 500 700 900 1100 1300 1400 1500

W/h-BN,W/GA Silicon Ref. Cell 1 Silicon Ref. Cell 2

Wavelength (nm)

EQE

(%)

50

45

40

35

30

25

20

15

10

5

Curre

nt D

ensit

y (m

A/cm

2 )

450 600 750 900 1050 1200 1350

Wavelength (nm)

40

Ref

lect

ive

abso

rpti

on (

%)

60

80

20

0

100

80

60

40

20

IQE

(%)

100

(b)

GaN(3.3eV)

x=0 x=0.3 x=0.02 x=0.29 x=0.79 x=1

HTM(Spiro-OMeTAD)

MASnI3-xBrxMAPb(I1-xBrx)3

(1.22 eV) (1.45 eV) (2.2 eV) (1.77 eV) (1.98 eV) (1.56 eV)

h-BN

(a)

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© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.

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12

Figure S 12 (a) J-V measurement of MASnI3 based solar cells with and without GA. Devices prepared with GA show better stability in air. (All devices prepared in air). (b) J-V measurement of MASnI3 based devices which are fabricated by following the same procedures as shown in refs. [5] and [13], Type I and Type II respectively. Type I and Type II cells have the similar architecture (FTO/d-TiO2/mp-TiO2/MASnI3/spiro-OMETAD/Au), but different ETL, HTL and Au thicknesses. The table shows the detailed comparison of our cells prepared and cells reported in the literature.

Name Jsc (mA/cm2)

Voc (V)

FF (%)

PCE (%)

Type I-(Ref.5) 16.8 0.88 42 6.4 Type II- (Ref. 13) 12.30 0.82 57 5.73 Type I-(This work) 13.40 0.79 52 5.49 Type II-(This work) 15.9 0.69 49 5.36

(a)

(b)

0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

20

10

Cur

rent

Den

sity

(m

A/c

m2 )

Voltage (V)

Type I-MASnI3-(Ref.5) Type I-MASnI3-(This work) Type II-MASnIBr2-(Ref.13) Type II-MASnIBr2-(This Work)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

20

15

5

10

Curre

nt D

ensit

y (m

A/c

m2 )

Voltage (V)

MASnI3/GA (150nm thick MASnI3) (Freshly illuminated) MASnI3/GA(150nm thick MASnI3) (Under illumination 10min) MASnI3/GA (300nm thick MASnI3) (Under illumination 10min)

MASnI3/GA (300nm thick MASnI3) (Freshly iluminated)

GaN

MASnI3

GA/HTMBack Contact

GaN

MASnI3

HTMBack Contact

MASnI3 (Freshly iluminated cell) MASnI3 (Under illumination 10min)

13

Figure S 13 (a) External quantum efficiency of the champion cell with integrated photocurrent (thick black line). Maximum possible Jsc, if the QE is 100% over the spectrum, is 49.4mA/cm2 and the expected Jsc is 42.32mA/cm2. The EQE spectrum for reference silicon cells is also shown under A.M 1.5. (b) The plot of reflective absorbtion and internal quantum efficiency (IQE) versus wavelength. The inset shows the composition profile and approximate band diagram of the cell.

The integrated current Density(Jsc) = 42.33 mA/cm2 Max possible Jsc with 100% absorption= 49.44 mA/cm2

!

"!

#!

$!

%!

&!

'!

(!

)!

*!

"!!

$!! &!! (!! *!! ""!! "$!! "&!! "(!! "*!!

100

80

60

40

20

300 500 700 900 1100 1300 1400 1500

W/h-BN,W/GA Silicon Ref. Cell 1 Silicon Ref. Cell 2

Wavelength (nm)

EQE

(%)

50

45

40

35

30

25

20

15

10

5

Curre

nt D

ensit

y (m

A/cm

2 )

450 600 750 900 1050 1200 1350

Wavelength (nm)

40

Ref

lect

ive

abso

rpti

on (

%)

60

80

20

0

100

80

60

40

20

IQE

(%)

100

(b)

GaN(3.3eV)

x=0 x=0.3 x=0.02 x=0.29 x=0.79 x=1

HTM(Spiro-OMeTAD)

MASnI3-xBrxMAPb(I1-xBrx)3

(1.22 eV) (1.45 eV) (2.2 eV) (1.77 eV) (1.98 eV) (1.56 eV)

h-BN

(a)

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© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.

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14

Figure S 14 Back surface pits on the GaN surface after etching. The cells display excellent light trapping properties due to these textured surface properties.

Pits

15

Figure S 15 Mott-Schottky analysis for the GaN/CH3NH3SnI3 interface. The dotted line is the linear fit to experimental data. The doping density of the perovskite film is found to be 1.4x1017cm-3. The inset shows the cross sectional SEM image of the GaN/ CH3NH3SnI3 device (scale bar is 50nm). The depletion width within the perovskite is calculated to be ~115nm.

-0.3 0.0 0.3 0 .6 0.9

Voltage (V)

0

C-2(x

1015

F-2 )

10

5

15

20 GaN

CH3NH3SnI3

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© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.

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14

Figure S 14 Back surface pits on the GaN surface after etching. The cells display excellent light trapping properties due to these textured surface properties.

Pits

15

Figure S 15 Mott-Schottky analysis for the GaN/CH3NH3SnI3 interface. The dotted line is the linear fit to experimental data. The doping density of the perovskite film is found to be 1.4x1017cm-3. The inset shows the cross sectional SEM image of the GaN/ CH3NH3SnI3 device (scale bar is 50nm). The depletion width within the perovskite is calculated to be ~115nm.

-0.3 0.0 0.3 0 .6 0.9

Voltage (V)

0

C-2(x

1015

F-2 )

10

5

15

20 GaN

CH3NH3SnI3


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