Supplementary data

Low-bandgap non-fullerene acceptors based on selenophene bridge and

alkylated indaceno[1,2-b:5,6-b′]dithiophene for organic solar cells

Xiaowei Zhang,a Qi Wang,a Ziqi Liang,a Miaomiao Li,a,* Yanhou Geng a,b

aSchool of Material Science and Engineering, Tianjin University, Tianjin 300072, P.

R. China.bTianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University, and

Collaborative Innovation Center of Chemical Science and Engineering (Tianjin),

Tianjin 300072, P. R. China.

N N

O

O O

O

N+ N+O--O

Fig. S1 Chemical structure of PDINO.

Fig. S2 1H NMR spectrum of compound 2.

Fig. S3 13C NMR spectrum of compound 2.

Fig. S4 1H NMR spectrum of IDT2SeC2C4.

Fig. S5 13C NMR spectrum of IDT2SeC2C4.

Fig. S6 1H NMR spectrum of IDT2SeC2C4-2F.

Fig. S7 13C NMR spectrum of IDT2SeC2C4-2F.

Fig. S8 1H NMR spectrum of IDT2SeC2C4-4F.

Fig. S9 13C NMR spectrum of IDT2SeC2C4-4F.

Fig. S10 The MALDI-TOF mass spectrum of compound 2.

Fig. S11 The MALDI-TOF mass spectrum of IDT2SeC2C4.

Fig. S12 The MALDI-TOF mass spectrum of IDT2SeC2C4-2F.

Fig. S13 The MALDI-TOF mass spectrum of IDT2SeC2C4-4F.

Fig. S14 TGA curves of IDT2SeC2C4, IDT2SeC2C4-2F and IDT2SeC2C4-4F in N2 with a heating rate of 10 ℃/min.

Fig. S15 The first cooling and the second heating DSC curves of IDT2SeC2C4, IDT2SeC2C4-2F and IDT2SeC2C4-4F in N2 with a heating/cooling rate of 10 /min.℃

Fig. S16 Thin film cyclic voltammograms (CV) of IDT2SeC2C4, IDT2SeC2C4-2F and IDT2SeC2C4-4F.

Fig. S17 J-V characteristics for the electron-only (a, b, c, d, e, f) devices fabricated with IDT2SeC2C4(a, d), IDT2SeC2C4-2F(b, e) and IDT2SeC2C4-4F(c, f).

Table S1 Carriers mobility of IDT2SeC2C4, IDT2SeC2C4-2F and IDT2SeC2C4-4F measured by the space charge limited current (SCLC) method.

Acceptor Treatments μe (cm2V-1s-1)

IDT2SeC2C4As cast 1.02

TA 1.33

IDT2SeC2C4-2FAs cast 1.51

TA 1.82

IDT2SeC2C4-4FAs cast 1.84

TA 2.11

Fig. S18 J-V characteristics for the electron-only (a, b, c, d) devices fabricated with IDT2Se(a, c) and IDT2Se-4F(b, d).

Table S2 Carriers mobility of IDT2Se and IDT2Se-4F measured by the space charge limited current (SCLC) method.

Acceptor Treatments μe (cm2V-1s-1)

IDT2SeAs cast 0.48

TA 0.71

IDT2Se-4FAs cast 0.88

TA 1.17

Fig. S19 out-of-plane (a) and In-plane (b) XRD patterns of neat films based on IDT2Se, IDT2Se-4F, IDT2SeC2C4, IDT2SeC2C4-2F and IDT2SeC2C4-4F.

Table S3. The detailed photovoltaic performances of OSCs based on PBDB-T:IDT2SeC2C4, PBDB-T:IDT2SeC2C4-2F and PBDB-T:IDT2SeC2C4-4F with different D:A ratio (wt:wt). The active layer thickness is ~80 nm.a

AcceptorD:A

ratioVOC (V) JSC (mA/cm2) FF (%) PCE (%)

IDT2SeC2C4

1:0.8 0.88±0.01 (0.88) 15.08±0.43 (15.51) 58.0±0.5 (58.5) 7.81±0.28 (8.09)

1:1 0.88±0.01 (0.88) 16.91±0.27 (17.18) 58.5±0.4 (58.9) 8.65±0.27 (8.92)

1:1.2 0.88±0.01 (0.88) 16.72±0.42 (17.14) 57.5±0.3 (57.8) 7.94±0.45 (8.39)

IDT2SeC2C4-2F

1:0.8 0.77±0.01 (0.77) 17.44±0.56 (18.00) 64.8±0.7 (65.5) 9.08±0.25 (9.33)

1:1 0.81±0.01 (0.81) 18.90±0.29 (19.19) 65.2±0.4 (65.6) 10.00±0.20 (10.20)

1:1.2 0.76±0.01 (0.76) 20.73±0.55 (21.28) 61.5±0.8 (62.3) 9.27±0.34 (9.61)

IDT2SeC2C4-4F

1:0.8 0.75±0.01 (0.75) 20.38±0.45 (20.83) 62.1±0.6 (62.7) 9.54±0.34 (9.88)

1:1 0.77±0.01 (0.77) 21.81±0.21 (22.02) 61.8±0.5 (62.3) 10.32±0.25 (10.57)

1:1.2 0.77±0.01 (0.77) 21.43±0.45 (21.88) 61.4±0.7 (62.1) 9.55±0.26 (9.81)aStatistical and optimal results are listed outside of parentheses and in parentheses, respectively.The average values are obtained from over 15 devices.

Table S4. The detailed photovoltaic performances of OSCs based on PBDB-T:IDT2SeC2C4, PBDB-T:IDT2SeC2C4-2F and PBDB-T:IDT2SeC2C4-4F with different active layer thickness. The D:A ratio (wt:wt) is 1:1. a

AcceptorThicknes

(nm)VOC (V) JSC (mA/cm2) FF (%) PCE (%)

IDT2SeC2C4

60 0.88 ±0.01 (0.88)14.15±0.43

(14.58)

56.0±0.5

(56.5)6.95±0.28 (7.23)

80 0.88±0.01 (0.88)16.91±0.27

(17.18)

58.5±0.4

(58.9)8.65±0.27 (8.92)

100 0.88±0.01 (0.88)15.50±0.58

(16.08)

57.3±0.6

(57.9)7.47±0.45 (7.92)

IDT2SeC2C4-2F

60 0.77±0.01 (0.77)17.27±0.56

(17.83)

60.1±0.6

(60.7)8.24± 0.59 (8.83)

80 0.81±0.01 (0.81)18.90±0.29

(19.19)

65.2±0.4

(65.6)

10.00±0.20

(10.20)

100 0.81 ±0.01 (0.81)18.10±0.62

(18.72)

65.0±0.5

(65.5)9.19±0.34 (9.53)

IDT2SeC2C4-4F

60 0.75±0.01 (0.75)18.45±0.25

(18.70)

52.1±0.6

(52.7)7.64±0.34 (7.78)

80 0.77±0.01 (0.77) 21.81±0.21 (22.02) 62.0±0.4 (62.4)10.32±0.25

(10.57)

100 0.77±0.01 (0.77) 21.81±0.21 61.8±0.5 10.32±0.25

(22.02) (62.3) (10.57)

aStatistical and optimal results are listed outside of parentheses and in parentheses, respectively. The average values are obtained from over 15 devices.

Table S5. The detailed photovoltaic performances of OSCs based on PBDB-T:IDT2SeC2C4 with with different treatments. The active layer thickness is ~80 nm, and the D:A ratio (wt:wt) is 1:1.a

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

SVA (s) TA (oC)

w/o

w/o 0.89±0.01 (0.89) 13.68±0.41 (14.09) 57.2±0.2 (57.4) 6.89±0.30 (7.19)

80 0.88±0.01 (0.88) 14.77±0.38 (15.25) 59.1±0.2 (59.3) 7.51±0.21 (7.72)

100 0.88±0.01 (0.88) 14.71±0.12 (14.83) 56.0±0.4 (56.4) 6.96±0.34 (7.30)

120 0.88±0.01 (0.88) 16.91±0.27 (17.18) 58.5±0.4 (58.9) 8.65±0.27 (8.92)

140 0.89±0.01 (0.89) 14.36±0.25 (14.61) 57.1±0.4 (57.5) 7.06±0.19 (7.25)

30

w/o

0.88±0.01 (0.88) 14.93±0.49 (15.32) 58.8±0.4 (59.2) 7.04±0.27 (7.31)

60 0.88±0.01 (0.88) 15.26±0.31 (15.57) 57.4±0.3 (57.7) 7.47±0.33 (7.80)

90 0.88±0.01 (0.88) 14.83±0.14 (14.97) 58.5±0.5 (59.0 ) 7.42±0.27 (7.69)

120 0.88±0.01 (0.88) 14.22±0.29 (14.51) 57.5±0.4 (57.9) 7.20±0.05 (7.25)

150 0.88±0.01 (0.88) 14.76±0.25 (15.01) 57.0±0.4 (57.4) 7.42±0.20 (7.62)

60120

0.88±0.01 (0.88) 16.66±0.38 (17.04) 57.4±0.3 (57.7) 8.37±0.24 (8.61)

90 0.89±0.01 (0.89) 16.35±0.34 (16.69) 58.9±0.4 (59.3) 8.35±0.23 (8.58)a Statistical and optimal results are listed outside of parentheses and in parentheses, respectively. The average values are obtained from over 15 devices.

Table S6. The detailed photovoltaic performances of OSCs based on PBDB-T:IDT2SeC2C4-2F with different treatments. The active layer thickness is ~80 nm, and the D:A ratio (wt:wt) is 1:1. a

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

SVA (s) TA (oC)

w/o

w/o 0.81±0.01 (0.81) 18.17±0.19 (18.36) 62.3±0.3 (62.6) 9.17±0.10 (9.30)

80 0.82±0.01 (0.82) 19.18±0.41 (19.59) 64.0±0.4 (64.4) 9.63±0.24 (9.87)

100 0.82±0.01 (0.82) 16.69±0.28 (16.97) 65.6±0.3 (65.9) 8.38±0.38 (8.76)

120 0.81±0.01 (0.81) 18.90±0.29 (19.19) 65.2±0.4 (65.6) 10.00±0.20 (10.20)

140 0.82±0.01 (0.82) 17.09±0.20 (17.29) 62.6±0.3 (62.9) 8.54±0.17 (8.71)

30

w/o

0.81±0.01 (0.81) 16.26±0.25 (16.51) 63.4±0.4 (63.8) 8.24±0.19 (8.43)

60 0.81±0.01 (0.81) 16.32±0.46 (16.78) 64.4±0.3 (64.7) 8.51±0.15 (8.66)

90 0.81±0.01 (0.81) 16.13±0.24 (16.37) 63.7±0.5 (64.2) 8.21±0.28 (8.49)

120 0.81±0.01 (0.81) 15.45±0.38 (15.83) 63.9±0.4 (64.3) 8.10±0.16 (8.26)

150 0.81±0.01 (0.81) 15.55±0.41 (15.96) 64.3±0.4 (64.7) 7.98±0.20 (8.18)

60120

0.82±0.01 (0.82) 17.67±0.44 (18.11) 64.9±0.4 (65.3) 9.25±0.23 (9.48)

90 0.82±0.01 (0.82) 17.64±0.42 (18.06) 64.4±0.4 (64.8) 9.16±0.23 (9.39)a Statistical and optimal results are listed outside of parentheses and in parentheses, respectively. The average values are obtained from over 15 devices.

Table S7. The detailed photovoltaic performances of OSCs based on PBDB-T:IDT2SeC2C4-4F with different treatments. The active layer thickness is ~80nm, and the D:A ratio (wt:wt) is 1:1. a

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

SVA (s) TA (oC)

w/o

w/o 0.77±0.01 (0.77) 20.48±0.20 (20.68) 60.2± 0.3 (60.5) 9.49±0.14 (9.63)

80 0.77±0.01 (0.77) 21.67±0.26 (21.92) 57.7±0.3 (58.0) 9.27±0.31 (9.58)

100 0.77±0.01 (0.77) 22.11±0.16 (22.27) 58.9±0.3 (59.2) 9.88±0.33 (10.21)

120 0.77±0.01 (0.77) 21.81±0.21 (22.02) 61.8±0.5 (62.3) 10.32±0.25 (10.57)

140 0.77±0.01 (0.77) 21.29±0.17 (21.46) 57.9±0.3 (58.2) 9.34±0.32 (9.65)

30

w/o

0.77±0.01 (0.77) 21.29±0.19 (21.58) 58.4±0.3 (58.7) 9.34±0.16 (9.50)

60 0.77±0.01 (0.77) 22.60±0.14 (22.74) 58.9±0.4 (59.3) 10.00±0.20 (10.20)

90 0.77±0.01 (0.77) 21.91±0.39 (22.30) 59.4±0.4 (59.8) 9.76±0.34 (10.10)

120 0.77±0.01 (0.77) 21.27±0.29 (21.56) 58.9±0.3 (59.2) 9.43±0.35 (9.78)

150s 0.77±0.01 (0.77) 19.85±0.27 (20.12) 58.7±0.3 (59.0) 8.63±0.33 (8.99)

60120℃

0.77±0.01 (0.77) 22.19±0.28 (22.47) 59.1±0.4 (59.5) 10.00±0.26 (10.26)

90 0.77±0.01 (0.77) 21.20±0.21 (21.41) 60.5±0.3 (60.8) 9.66±0.35 (10.01)a Statistical and optimal results are listed outside of parentheses and in parentheses, respectively. The average values are obtained from over 15 devices.

Table S8. The detailed photovoltaic performances of OSCs based on PBDB-T:IDT2Se and PBDB-T:IDT2Se-4F with different treatments. The active layer thickness is ~80nm, and the D:A ratio (wt:wt) is 1:1. a

Acceptor TA VOC (V) JSC (mA/cm2) FF (%) PCE (%)

IDT2Se

w/o 0.89±0.01 (0.89) 14.51±0.49 (15.00) 58.9±0.4 (59.3) 7.61±0.46 (8.07)

120℃ 0.89±0.01 (0.89) 15.58±0.29 (15.87) 57.7±0.3 (58.0) 7.90±0.29 (8.19)

IDT2Se-4Fw/o 0.81±0.01 (0.81) 14.53±0.29 (14.82) 60.8±0.3 (61.1) 7.20±0.11 (7.31)

120℃ 0.81±0.01 (0.81) 16.88±0.32 (17.20) 60.6±0.4 (61.0) 8.10±0.39 (8.49)a Statistical and optimal results are listed outside of parentheses and in parentheses, respectively. The average values are obtained from over 15 devices.

Fig. S20 J-V characteristics for the electron-only (a, b, c, d, e, f) and hole-only (g, h, i, j, k, l) devices fabricated with PBDB-T:IDT2SeC2C4, PBDB-T:IDT2SeC2C4-2F and PBDB-T:IDT2SeC2C4-4F. The solid lines represent the fit using a model of single carrier SCLC with field-independent mobility.

Table S9 Carriers mobility of PBDB-T:IDT2SeC2C4, PBDB-T:IDT2SeC2C4-2F and PBDB-T:IDT2SeC2C4-4F blends measured by SCLC method.

Blend film Treatmentsμh

(cm2V-1s-1)

μe

(cm2V-1s-1)μh/μe

IDT2SeC2C4As cast 1.33 0.45 2.95

TA 1.53 0.65 2.35

IDT2SeC2C4-2FAs cast 1.48 1.08 1.36

TA 1.85 1.47 1.26

IDT2SeC2C4-4FAs cast 1.83 1.38 1.33

TA 2.14 1.72 1.24

Fig. S21 J-V characteristics for the electron-only (a, b, c, d) and hole-only (e,f g, h) devices fabricated with PBDB-T:IDT2Se, and PBDB-T:IDT2Se-4F. The solid lines represent the fit using a model of single carrier SCLC with field-independent mobility.

Table S10 Carriers mobility of PBDB-T:IDT2Se and PBDB-T:IDT2Se-4F blends measured by SCLC method with chloroform as solvent.

Blend film Treatmentsμh

(cm2V-1s-1)

μe

(cm2V-1s-1)μh/μe

PBDB-T:IDT2SeAs cast 0.48 0.13 3.69

TA 0.81 0.29 2.80

PBDB-T:IDT2Se-4FAs cast 0.61 0.25 2.44

TA 1.03 0.47 2.21

Fig. S22. AFM height (a-c) and phase (d-f) images of PBDB-T:IDT2SeC2C4 (a, d), PBDB-T:IDT2SeC2C4-2F (b, e), and PBDB-T:IDT2SeC2C4-4F (c, f) blend films without any treatment.

Fig. S23. AFM height (a, b) and phase (c, d) images of PBDB-T:IDT2Se (a, c), and PBDB-T:IDT2Se-4F (b, d) blend film.

Fig. S24 Out-of-plane (a) and in-plane (b) XRD patterns of IDT2SeC2C4, IDT2SeC2C4-2F and IDT2SeC2C4-4F neat films.

Fig. S25 Out-of-plane (a) and in-plane (b) XRD patterns of PBDB-T neat films.

Fig. S26 Out-of-plane (a) and in-plane (b) XRD patterns of PBDB-T:IDT2Se, PBDB-T:IDT2Se-4F blend films.