Supporting information Inverted P3HT:PC61BM organic solar cells incorporating a -extended squaraine dye with H- and/or J -aggregation. Sergey V. Dayneko, Abby-Jo Payne and Gregory C. Welch* Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary AB, Canada, T2N 1N4 *To whom correspondence should be addressed. Phone: 403-210-7603 e-mail: gregory.welch@ucalgary.ca S-1
Materials The P3HT polymer was purchased from Brilliant Matters and used as received. The SQIQ-A molecule was prepared according to literature: Org. Biomol. Chem. 2017, 15, 3310. All remaining materials were purchased from Aldrich Chemicals and used without further purification. ZnO Sol-Gel: The ZnO sol-gel was prepared by dissolving 0.46 mol L -1 zinc acetate dehydrate and 0.46 mol L -1 ethanolamine in 2-methoxyethanol. The solution was stirred overnight at room temperature. Experimental Section Solar Cells Fabrication and Testing: Solar cells were fabricated on ITO-coated glass substrates, which were first cleaned by sequentially ultra-sonicating in detergent and de-ionized water, acetone, and then isopropanol before use. ITO substrates were first pretreated by UV-ozone for 30 minutes, then the ZnO precursor solution was spin-cast onto the ITO substrate at a speed of 4000 rpm followed by thermal annealing at 200 C in air for 15 minutes. Active layer solutions (P3HT:PC61BM:SQIQ-A weight ratios 1:1:0, 1:1:0.1, 1:1:0.2, 1:1:0.3) were prepared in 1,2-odichlorobenzene (ODCB) with total compound concentration of 40 mg ml -1. The substrates were then kept in an N2 atmosphere glovebox overnight before evaporating MoOx and Ag. The evaporation of 10 nm of MoOx followed by 100 nm of Ag were thermally deposited under vacuum (10-6 Torr). Current density-voltage (JV) characteristics were measured using a Keithley 2420 Source Measure Unit. Solar cell performance used an Air Mass 1.5 Global (AM 1.5G) Solar Simulator (Newport, Model 92251A-1000) with an irradiation intensity of 100 mw cm -2, which was measured by a calibrated silicon solar cell and a readout meter (Newport, Model 91150V). EQE spectra were measured using a QEX7 Solar Cell Spectral Response/QE/IPCE Measurement S-2
System (PV Measurement, Model QEX7) with an optical lens to focus the light into an area about 0.04 cm 2, smaller than the dot cell. The silicon photodiode was used to calibrate the EQE measurement system from 300 to 1100 nm. Equipment UV-vis absorption measurements were carried out on an Agilent Technologies Cary 60 UV-vis spectrometer at room temperature. The photoluminescence spectra measurements were recorded using an Agilent Technologies Cary Eclipse fluorescence spectrophotometer at room temperature. Atomic force microscopy (AFM) images were obtained using a TT2-AFM (AFM workshop) in tapping mode with images processed using Gwyddion software. All X-ray diffraction experiments were performed on a PROTO AXRD Benchtop Powder Diffractometer using θ-2θ scans and Cu K-α radiation. The polarized optical microscopy (POM) images of the solar cells were measured on an Olympus BX53. S-3
(a) (b) (c) (d) Figure S1. Absorption spectra of P3HT:PC61BM:SQIQ-A (1:1:0.3) blended films. A) as-cast and solvent vapor annealed (SVA) using chloroform (CF). B) the CF-SVA films treated by thermal annealing at 130ºC for 10 minutes. C) as-cast and solvent vapor annealed (SVA) using tetrahydrofuran (THF). D) the THF-SVA films treated by thermal annealing at 130ºC for 10 minutes. S-4
Figure S2. The J-V characteristics (left) and EQE (right) of P3HT:PC61BM (ratio 1:1) and P3HT:PC61BM:SQIQ-A (ratio 1:1:0.1, 1:1:0.2 and 1:1:0.3). All BHJ OSCs annealed at 130 C for 10 minutes. Table S1. Photovoltaic performance of the ternary blend (P3HT:PC61BM:SQIQ-A) OSCs with different concentrations of SQIQ-A. P3HT:PCBM:SQIQ-A ratio Voc (V) Jsc (ma cm -2 ) FF (%) PCE (%) (by mass) 1:1:0 0.57 10.61 51 3.1 1:1:0.1 0.57 7.98 52 2.3 1:1:0.2 0.58 7.08 52 2.1 1:1:0.3 0.58 6.45 54 2.0 Device size: 9 mm 2. Substrate Size: 15 x 15 x 0.7 mm. All films thermally annealed at 130 C for 10 minutes. S-5
Figure S3. X-ray diffraction (XRD) patterns of P3HT:PC61BM films. TOP) as-cast. BOTTOM) TA at 130ºC for 10 minutes (bottom). Figure S4. X-ray diffraction (XRD) patterns of P3HT:PC61BM films. TOP) SVA with CF for 3- minutes. BOTTOM) SVA with CF for 3-minutes + TA at 130ºC for 10 minutes. CF = CHCl3. S-6
Figure S5. X-ray diffraction (XRD) patterns of P3HT:PC61BM films. TOP) SVA with THF for 1.5-minutes. BOTTOM) SVA with THF for 1.5-minutes + TA at 130ºC for 10 minutes. THF = C4H8O. Figure S6. X-ray diffraction (XRD) patterns of P3HT:PC61BM films. TOP) SVA with THF for 3-minutes. BOTTOM) SVA with THF for 3-minutes + TA at 130ºC for 10 minutes. THF = C4H8O. S-7
Figure S7. X-ray diffraction (XRD) patterns of P3HT:PC61BM:SQIQ-A films. TOP) as-cast. BOTTOM) TA at 130ºC for 10 minutes (bottom). Figure S8. X-ray diffraction (XRD) patterns of P3HT:PC61BM films SVA with CF for 3- minutes and TA at 130ºC for 10 minutes. CF = CHCl3. S-8
Figure S9. X-ray diffraction (XRD) patterns of P3HT:PC61BM films SVA with THF for 1.5- minutes and TA at 130ºC for 10 minutes. THF = C4H8O. Figure S10. X-ray diffraction (XRD) patterns of P3HT:PC61BM films SVA with THF for 3- minutes and TA at 130ºC for 10 minutes. THF = C4H8O. S-9
Figure S11. Optical microscopy images of P3HT:PC61BM:SQIQ-A blended films. A) CF-SVA 3 minutes. B) THF-SVA 1.5 minutes. C) THF-SVA 3 minutes. All films TA at 130 C for 10 minutes. Polarized optical microscopy images of P3HT:PC61BM:SQIQ-A blended films. D) CF- SVA 3 minutes. E) THF-SVA 1.5 minutes. F) THF-SVA 3 minutes. All films TA at 130 C for 10 minutes. CF = CHCl3 and THF = C4H8O. Figure S12. Optical microscopy images of P3HT:PC61BM:SQIQ-A blended films. A) THF-SVA 5 minutes. B) + TA at 130 C for 10 minutes. C) THF-SVA 10 minutes D) + TA at 130 C for 10 minutes. Polarized optical microscopy images of P3HT:PC61BM:SQIQ-A blended films. E) THF-SVA 5 minutes. F) + TA at 130 C for 10 minutes. G) THF-SVA 10 minutes H) + TA at 130 C for 10 minutes. CF = CHCl3 and THF = C4H8O. S-10