Highly Efficient Perovskite Solar Cells with Substantial ... - Nature

Highly Efficient Perovskite Solar Cells with Substantial Reduction of Lead Content Chong Liu†, Jiandong Fan†‡*, Hongliang Li†, Cuiling Zhang†, Yaohua Mai†‡* †

Institute of Photovoltaics, College of Physics Science and Technology, Hebei University, Baoding, 071002, China ‡

Institute of New Energy Technology ,College of Information and Technology, Jinan University, Guangzhou, 510632, China E-mail: (J. F.) [email protected]; E-mail: (Y. M.) [email protected].

1

(x =1 )i

@ n

Intensity (a.u.)

(x =1 )i

n

(x =0 .5 )i

DM

n

@

@#

@ SnI2/PbI2

DM F

#

# FTO & PbI2(DMSO)x SnI2(DMSO)x

#

*

*

SO

DM SO

،¤ DM F

&

(x=

0) in

DM SO

5

*

،¤D MF

10

*

&

&

&

15

*

*

20

25

30

35

40

2Theta (deg) Supplementary Figure 1. XRD patterns of PbI2/(SnI2)·(DMSO)x complexes with different Sn concentrations after post annealing treatment at 90 ºC for 10 min.

C=O

C=O

B

C-O

SnI2 in DMSO/DMF_60C/10min

Intensity (a.u.)

B

C-O C-S

PbI2 in DMSO/DMF_W/O anneal

C-S

SnI2 in DMSO/DMF_W/O anneal

C-S

C-O C-S

PbI2 in DMSO/DMF_60C/10min

B

Intensity (a.u.)

C-O

PbI2 in DMSO/DMF_140C/20min

SnI2 in DMSO/DMF_140C/20min

500

1000 1500 2000 2500 3000 3500 4000

500

Wavenumber (cm-1)

1000 1500 2000 2500 3000 3500 4000

Wavenumber (cm-1)

Supplementary Figure 2. FTIR spectra of the perovskite layer deposited from DMSO/DMF solution before and after annealing showing the characteristic C−S and C−O stretching vibrations from the Sn2+- and Pb2+- coordinated DMSO solvent at 960 and 1012 cm−1, and C=O stretching vibrations from the Sn2+- and/or Pb2+- coordinated DMF solvent at 1389 and 1688 cm−1. (a) SnI2·(DMSO)x intermediates; (b) PbI2·(DMSO)x intermediates.

2

Supplementary Figure 3. SEM images of PbI2/(SnI2)·(DMSO)x complexes with different Sn concentrations.

3

Supplementary

Figure 4. SEM images of CH3NH3Pb(1−x)SnxI3 (0≤x≤1) thin films with

different Sn concentrations.

O

I

X=0

3d5/2

Sn

3d3/2

Pb

4f7/2

4f5/2

Intensity (a.u.)

X=0.25

X=0.5

1s

530

3d5/2

X=1 535

540

Binding Energy (eV)

545

620

625

630

635

640

485

490

3d3/2

495

Binding Energy (eV)

Binding Energy (eV)

500

140

145

150

Binding Energy (eV)

Supplementary Figure 5. XPS spectra of Pb, I, Sn and O in CH3NH3Pb(1−x)SnxI3 (0≤x≤1) thin films with different Sn concentrations. 4

PCBM/BCP/Ag MAPb0.75Sn0.25I3 PEDOT:PSS FTO

1 μm

Supplementary Figure 6. The cross-sectional SEM image of CH3NH3Pb0.75Sn0.25I3 solar cell with inverted structure.

20

16

18

14

12

12 PCE

10 8

10 8

PCE (%)

Current Density (mA/cm2)

Current Density

14

18

nsity

10

10

8

8

4

2

2

0

0

0

-2

-2

-2

50 100 150 200 250 300 350 400 450 Time (s)

Current De

12

6

14 12

14

4

0

(b)

16

6

-50

16

PCE

6

PCE (%)

(a)

16

Current Density (mA/cm2)

18

6 4

4

2

2 0

0

100

200

300

400

500

Time (s)

Supplementary Figure 7. Photocurrent density and power conversion efficiency as a function of time for the same cell held close to 0.79 V and 0.60 V forward bias, respectively. (a) CH3NH3PbI3; (b)CH3NH3Pb0.75Sn0.25I3

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