Page S1

Electronic Supplementary Information (ESI)

Quantum dot material engineering boosting quantum dot sensitized solar cells

efficiency over 13%

Huashang Rao,ab Mengsi Zhou,ac Zhenxiao Pan,*ab and Xinhua Zhong*ab

aKey Laboratory for Biobased Materials and Energy of Ministry of Education, College of

Materials and Energy, South China Agricultural University, 483 Wushan Road, Guangzhou

510642, ChinabGuangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, ChinacSchool of Chemistry and Molecular Engineering, East China University of Science and

Technology, Shanghai 200237, China

*Corresponding authors

Email: zxpan@scau.edu.cn (for Z. P.)

zhongxh@scau.edu.cn (for X. Z.)

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.This journal is © The Royal Society of Chemistry 2020

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Table S1. ZnSe thickness dependent ZCISe/ZnSe cell devices’ photovoltaic performance parameters

ZnSe thickness Jsc (mA·cm-2) Voc (V) FF PCE (%)

average 26.69 0.770 0.668 13.71±0.111 MLchampion 26.70 0.780 0.664 13.84

average 26.04 0.773 0.664 13.36±0.112ML

champion 26.19 0.773 0.665 13.46

average 25.68 0.771 0.663 13.14±0.103ML

champion 25.75 0.775 0.663 13.23

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Fig. S1 J−V curves for ZCISe/ZnSe QDs with different ZnSe shell thickness.

0.0 0.2 0.4 0.6 0.80

5

10

15

20

25

ZCISe/1ZnSe ZCISe/2ZnSe ZCISe/3ZnSe

Curr

ent d

ensi

ty (m

A/cm

2 )

Potential (V)

Page S4

Fig. S2 XRD patterns of ZCISe, and derived ZCISe/ZnSe QDs. Line XRD pattern corresponds to bulk tetragonal chalcopyrite CISe.

20 30 40 50 60

(312)(220)

Coun

ts (a

.u.)

2

ZCISe ZCISe/ZnSe

(112)

Page S5

Fig. S3 ZnSe thickness dependent (a) UV−vis absorption, and (b) PL emission spectra.

650 700 750 800 850 9000

50

100

150

200

ZCISe ZCISe/1ZnSe ZCISe/2ZnSe ZCISe/3ZnSe

Inte

nsity

(a.u

.)

Wavelength (nm)400 600 800 1000

ZCISe ZCISe/1ZnSe ZCISe/2ZnSe ZCISe/3ZnSe

Norm

alize

d Ab

sorb

ance

Wavelength (nm)

a) b)

Page S6

Table S2. Photovoltaic parameters of ZCISe and ZCISe/ZnSe core/shell based QDSCs under the illumination of one full sun intensity (100 mW/cm2).

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

ZCISeNMC/Ti

26.2526.1026.4526.0926.30

0.7520.7480.7460.7540.744

0.6350.6330.6320.6350.645

12.5412.3512.5712.4912.65

Average 26.22±0.17 0.750±0.004 0.634±0.002 12.49±0.10

ZCISe/ZnSeNMC/Ti

27.0026.5426.7026.6826.55

0.7690.7610.7800.7650.776

0.6640.6740.6640.6760.660

13.7913.6213.8413.6913.59

Average 26.69±0.19 0.770±0.008 0.668±0.007 13.71±0.11

Page S7

Fig. S4 J−V curves of ZCISe and ZCISe/ZnSe core/shell QDs-based cells under the illumination of one full sun intensity (100 mW/cm2).

0.0 0.20.4

0.60.8

05

1015202530

5431

Curr

ent d

ensi

ty (

mA

/ cm

2 )

SamplesPotential ( V )

20.0 0.2

0.40.6

0.8

05

1015202530

5432

Curr

ent d

ensi

ty (m

A/cm

2 )

SamplesPotential ( V )

1

a) b)

ZCISe ZCISe/ZnSe

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Certified photovoltaic performance of ZCISe/ZnSe QDSC by CPVT (National

Centre of Supervision and Inspection on Solar Photovoltaic Products Quality, China)

Page S9

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Fig. S5 ZCISe and ZCISe/ZnSe sensitized TiO2 mesoporous film electrodes. It is noted that the measured film is consisted of 5.0 µm transparent P25 layer.

600 800 10000

1

2

3

4

ZCISe ZCISe/ZnSe

Abs

orba

nce

Wavelength (nm)

Page S11

Fig. S6 Nyquist curves at different forward bias for (a) ZCISe, and (b) ZCISe/ZnSe based QDSCs.

0 20 40 60 80 1000

50

100

150

200

-Z''(

)

Z'()

350 mV 450 mV 550 mV 650 mV

ZCISea)

0 20 40 60 80 1000

50

100

150

200

-Z''(

)

Z'()

350 mV 450 mV 550mV 650 mV

b) ZCISe/ZnSe

Page S12

Table S3. Extracted EIS parameter values for ZCISe and ZCISe/ZnSe based cells at

bias voltage of −0.65 V.

Cells Rs (Ω·cm2) RCE (Ω·cm2)

Cμ (mF·cm-

2)Rrec

(Ω·cm2) τn (ms)

ZCISe 4.66 1.80 19.30 37.91 731.6

ZCISe/ZnSe 4.55 2.36 18.06 62.30 1125.0