BODIPY-Based Conjugated Polymers for Use as Dopant-Free. Hole Transporting Materials for Durable Perovskite Solar

Transcription

1 Supporting Information BODIPY-Based Conjugated Polymers for Use as Dopant-Free Hole Transporting Materials for Durable Perovskite Solar Cells: Selective Tuning of HOMO/LUMO Levels Minkyu Kyeong, Jinho Lee, Kwanghee Lee *, and Sukwon Hong *, School of Materials Science and Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea Heeger Center for Advanced Materials, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea Research Institute for Solar and Sustainable Energies, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheom dan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea Electronic mail: S-1

2 S-2

3 Figure S1. (a) Onset oxidation potential was obtained by cyclic voltammogram in 0.1 M of Bu 4 NClO 4 /MeCN solutions under air atmosphere. (b) Absorption spectra in chloroform solution. (c) Thermogravimetric analysis in flow of N 2. S-3

4 Figure S2. (a) Water and (b) DMF contact angle images of pristine HTLs and PFN-modified HTLs. S-4

5 K6 K6/PFN Intensity (a.u.) K5 K5/PFN K3 K3/PFN K1 K1/PFN Binding energy (ev) Figure S3. Ultraviolet photoelectron spectroscopy spectra of pristine HTLs and PFNmodified HTLs. S-5

6 Figure S4. Photograph of polymer and perovskite films deposited on the corresponding polymer thin films. S-6

7 Figure S5. Scanning electron microscopy (SEM) images of the Perovskite films fabricated on the various polymer substrates. S-7

8 K6 K5 Intensity (a.u.) K3 K θ ( ) Figure S6. XRD spectra of the perovskite polycrystalline films fabricated on the HTL/PFN layers. S-8

9 Figure S7. Device structure and corresponding J V characteristics of the PSC with PFN-only HTM scanned in reverse and forward directions. Table S1. Details of the PSC with PFN-only HTM. HTL V oc (V) J sc (ma/cm2) FF PCE (%) PFN only (Reverse) PFN only (Forward) S-9

10 Figure S8. Cross-sectional scanning electron microscopy (SEM) image of the PSC. S-10

11 Figure S9. (a) J-V characteristics of the PSCs with various HTMs scanned in reverse and forward directions. (b) Stabilized power output curve for PSCs with K1 HTM. S-11

12 Figure S10. Device structure and corresponding J V characteristics of a hole-only device with polymer layers (from K1 to K6). Black line indicates fit to the Mott Gurney law of curve in the range of a space charge limited current (SCLC) regime (slope = 2). S-12

13 Table S2. The calculated hole mobilities are shown in table. Polymer SCLC µ h (cm 2 V -1 s -1 ) K K K K K K S-13

14 Current Density (ma cm -2 ) PEDOT:PSS Voltage (V) Figure S11. J V characteristics of the PSCs with PEDOT:PSS. S-14

15 Figure S12. Decay curve of performance parameters for PSCs with PEDOT:PSS and K1/PFN HTLs as function of exposure time. (a) PCE, (b) V oc, (c) J sc and (d) FF. S-15

16 PCE (%) Under illumination (N2) PEDOT:PSS K1/PFN Maximum power point tracking Time (h) Figure S13. Operational stability of PSC measured by tracking maximum power point (MPP) for 200 hours under continuous illumination in N2 atmosphere. S-16

17 Cost estimation We estimated the cost of our HTMs with the assumption of the previous paper. S1 Based on our synthetic strategy, estimated cost (C g ) was calculated in the light of starting materials, types of purification processes, yield, and synthetic steps. Cost-per-peak Watt (C w ) was estimated based on the following equation: = (1) where p and t is density (assumed to be 1 g cm -3 ) and thickness of the corresponding hole transporting materials (assumed to be 10 nm), η is power conversion efficiency, and I is the solar insolation under peak condition (assumed to be 1000 W m -2 ). The results are summarized in Table S3. Table S3. The estimated cost of new HTMs. HTM Estimated cost ($ g -1 ) Cost-per-peak Watt ($ W -1 p ) K X 10-2 K X 10-2 K X 10-2 K X 10-2 K X 10-3 K X 10-2 S-17

18 Synthetic details of the HTM polymers CH 3 N N B F F H N O O F 3 C O CF 3 H N H N 1) COCF 3 C 11 H 23 O 1) Cl H N 2) BF 3 Et 2 O Et 3 N C 11 H 23 CF 3 N N B F F NIS I R 2 N N B F F R 2 = Me (a) CF 3 (b) C 11 H 23 (c) I 2) BF 3 Et 2 O Et 3 N N N B F F C 4 H 9 C 2 H 5 C 8 H 17 C 6 H 13 C 8 H 17 C 6 H 13 C 12 H 25 C 10 H 21 O O O O S S S S Me 3 Sn SnMe 3 S Me 3 Sn SnMe 3 S Me 3 Sn SnMe 3 S Me 3 Sn SnMe 3 S O O O O C 2 H 5 C 4 H 9 C 6 H 13 C 8 H 17 C 6 H 13 C 8 H 17 C 10 H 21 C 12 H 25 (1) (2) (3) (4) (1) + (a) K1 (1) + (b) K2 (2) + (a) K3 (3) + (b) K4 (3) + (c) K5 (4) + (a) K6 Scheme S1. Overall synthetic scheme of the HTM polymers. Iodination of BODIPY derivatives Certain BODIPY (0.76 mmol, 1 equiv) was dissolved in CH 2 Cl 2 (35 ml, 22 mm), and N- iodosuccinimide (3.05 mmol, 4 equiv) was added in one portion. The mixture was stirred for S-18

19 12 hours in the Schlenk flask covered with Al foil. After reaction, all the volatiles were removed in vacuo and the crude products were purified via flash silica-gel column chromatography affording desired compounds. General procedure of polymerization Stannylated BDT derivatives, diiodinated BODIPY derivatives and palladium catalysts were dissolved in dry and degassed toluene under Ar atmosphere. The solution was refluxed for certain time, and then cooled to room temperature. Subsequently, the polymer solution was poured into methanol. The precipitate was filtered and it was subjected to Soxhlet extraction with methanol, hexane, and chloroform sequentially until the washed solution of each extraction was colorless. The chloroform fraction was concentrated and dried under vacuum to afford product. Poly[BDT(EH)-BODIPY(CH 3 )] (K1) Stannylated BDT(EH) (139 mg, 0.18 mmol), iodinated BODIPY(CH 3 ) (92 mg, 0.18 mmol), Pd 2 (dba) 3 (5 mg, 5.4 µmol, 3 mol%) and P(ο-tolyl) 3 (13 mg, 43 µmol, 24 mol%) in 10 ml of toluene were used to synthesize desired polymer. The reaction was proceeded for 16 hours. The purified product was obtained as dark red solid (48 mg, 68 µmol, 38%). 1 H NMR (400 MHz, CDCl 3, δ): 7.54 (s, 2H), 7.30 (s, 4H), 7.27 (s, 2H), 4.24 (br, 20H), 2.78 (br, 10H), 2.68 (br, 22H), 2.55 (br, 22H), 1.82 (br, 8H), 1.40 (br, 44H), 1.02 (br, 28H), 0.94 (br, 32H). S-19

20 Poly[BDT(EH)-BODIPY(CF 3 )] (K2) Stannylated BDT(EH) (202 mg, 0.26 mmol), iodinated BODIPY(CF 3 ) (148 mg, 0.26 mmol), Pd(PPh 3 ) 4 (9 mg, 7.8 µmol, 3 mol%)) in 12 ml of toluene were used to synthesize desired polymer. The reaction was proceeded for 2 days. The purified product was obtained as dark blue solid (161 mg, 212 µmol, 81%). 1 H NMR (400 MHz, CDCl 3, δ): 7.35 (s, 2H), 4.24 (br, 4H), 2.72 (br, 6H), 2.42 (br, 6H), 1.84 (br, 2H), 1.40 (br, 12H), 1.04 (br, 16H). 19 F NMR (376 Hz, CDCl 3, δ): -51.6, Poly[BDT(HD)-BODIPY(CH 3 )] (K3) Stannylated BDT(HD) (179 mg, 0.18 mmol), iodinated BODIPY(CH 3 ) (92 mg, 0.18 mmol) and Pd(PPh 3 ) 4 (6 mg, 5.4 µmol, 3 mol%) in 10 ml of toluene were used to synthesize desired polymer. The reaction was proceeded for 2 days. The purified product was obtained as dark red solid (161 mg, 173 µmol, 96%). 1 H NMR (400 MHz, CDCl 3, δ): 7.29 (s, 2H), 4.23 (br, 4H), 2.78 (br, 2H), 2.69 (br, 5H), 2.55 (br, 4H), 1.87 (br, 2H), 1.63 (br, 4H), 1.25 (br, 48H), 0.88 (br, 12H). Poly[BDT(HD)-BODIPY(CF 3 )] (K4) Stannylated BDT(HD) (179 mg, 0.18 mmol), iodinated BODIPY(CF 3 ) (102 mg, 0.18 mmol), Pd(PPh 3 ) 4 (6 mg, 5.4 µmol, 3 mol%) in 10 ml of toluene were used to synthesize desired polymer. The reaction was proceeded for 2 days. The purified product was obtained as dark red solid (106 mg, 107 µmol, 60%). 1 H NMR (400 MHz, CDCl 3, δ): 7.35 (s, 2H), 4.24 (br, 4H), 2.73 (br, 6H), 2.42 (br, 6H), 1.89 (br, 2H), 1.64 (br, 4H), 1.31 (br, 42H), 0.87 (br, 12H). S-20

21 19 F NMR (376 Hz, CDCl 3, δ): -51.7, Poly[BDT(HD)-BODIPY(C11)] (K5) Stannylated BDT(HD) (179 mg, 0.18 mmol), iodinated BODIPY(C11) (118 mg, 0.18 mmol) and Pd(PPh 3 ) 4 (6 mg, 5.4 µmol, 3 mol%) in 10 ml of toluene were used to synthesize desired polymer. The reaction was proceeded for 2 days. The purified product was obtained as dark red solid (156 mg, 146 µmol, 81%). 1 H NMR (400 MHz, CDCl 3, δ): 7.31 (s, 2H), 4.24 (br, 4H), 2.68 (br, 6H), 2.55 (br, 6H), 1.90 (br, 2H), 1.65 (br, 4H), 1.25 (br, 62H), 0.87 (br, 15H). Poly[BDT(DT)-BODIPY(CH 3 )] (K6) Stannylated BDT(DT) (213 mg, 0.17 mmol), iodinated BODIPY(CH 3 ) (89 mg, 0.17 mmol) and Pd(PPh 3 ) 4 (6 mg, 5.4 µmol, 3 mol%) in 9 ml of toluene were used to synthesize desired polymer. The reaction was proceeded for 2 days. The purified product was obtained as dark red solid (184 mg, 159 µmol, 94%). 1 H NMR (400 MHz, CDCl 3, δ): 7.29 (s, 2H), 4.24 (br, 4H), 2.69 (br, 6H), 2.55 (br, 6H), 1.89 (br, 2H), 1.63 (br, 3H), 1.25 (br, 80H), 0.86 (br, 12H). S-21

22 Figure S14. 1 H NMR of diiodinated BODIPY(CF3). S-22

23 Figure S C NMR of diiodinated BODIPY(CF3). S-23

24 Figure S16. 1 H NMR of diiodinated BODIPY(C11). S-24

25 Figure S C NMR of diiodinated BODIPY(C11). S-25

26 Figure S18. 1 H NMR of K1. S-26

27 Figure S19. 1 H NMR of K2. S-27

28 Figure S F NMR of K2. S-28

29 Figure S21. 1 H NMR of K3. S-29

30 Figure S22. 1 H NMR of K4. S-30

31 Figure S F NMR of K4. S-31

32 Figure S24. 1 H NMR of K5. S-32

33 Figure S25. 1 H NMR of K6. S-33

34 Figure S26. GPC graphs of K1, K2 and K3. S-34

35 Figure S27. GPC graphs of K4, K5 and K6. S-35

36 References (S1) Petrus, M. L.; Bein, T.; Dingemans, T. J.; Docampo, P. A Low Cost Azomethine-Based Hole Transporting Material for Perovskite Photovoltaics. Journal of Materials Chemistry A 2015, 3, S-36