Copyright WILEY-VCH Verlag GmbH & Co. KGaA, 69469 Weinheim, Germany, 2016. Supporting Information for Adv. Mater., DOI: 10.1002/adma.201602696 Stable Low-Bandgap Pb Sn Binary Perovskites for Tandem Solar Cells Zhibin Yang, Adharsh Rajagopal, Chu-Chen Chueh, Sae Byeok Jo, Bo Liu, Ting Zhao, and Alex K.-Y. Jen*
Supporting Information Stable Low Bandgap Pb-Sn Binary Perovskites for Tandem Solar Cells Zhibin Yang, Adharsh Rajagopal, Chu-Chen Chueh, Sae Byeok Jo, Bo Liu, Ting Zhao, and Alex K.-Y. Jen* Dr. Z. Yang, A. Rajagopal, Dr. C.-C. Chueh, Dr. S. B. Jo, Dr. B. Liu, T. Zhao, and Prof. A. K.-Y. Jen Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195-2120, USA * Corresponding author. E-mail: ajen@u.washington.edu Keywords: Sn-based perovskite, low bandgap, compositional engineering, tandem solar cells Figure S1. Summary of the reported perovskite based tandem solar cells with different configurations. [S1-S15] 1
Figure S2. SEM images of the compositional MAPb1-xSnxI3 perovksites with Sn content of 0% (a and f), 25% (b and g), 50% (c and h), 75% (d and i) and 100% (e and j) on PEDOT:PSS films. 2
Figure S3. X-ray diffraction spectra of MAPb 1-x Sn x I 3 perovksites with Sn content of 0%, 25%, 50%, 75% and 100%. Figure S4. SEM images of the MAPb 0.75 Sn 0.25 I 3-x Cl x perovksites with different magnification. 3
Figure S5. Roughness measurement of the compositional MAPb 0.75 Sn 0.25 I 3-x Cl x and MAPb 0.75 Sn 0.25 I 3 perovksites prepared by chlorine assistanted deposition method (a) and solvent washing method (b), respectively. 4
Figure S6. Normalized ultraviolet photoelectron spectra of the MAPb 1-x Sn x I 3 perovskites with Sn content of 0%, 25%, 50%, 75% and 100%. Figure S6b is the magnified figure of Figure S6a. Figure S7. SEM image of the compositional MAPb 0.75 Sn 0.25 I 3 perovskite on NiO x film. 5
Figure S8. Photovoltaic performance and possible mechanism of the compositional MAPb 0.75 Sn 0.25 I 3 perovksite solar cells with NiOx and PEDOT:PSS as hole transporting materials. Figure S9. Ground state absorption (black solid line), photoluminescence (black dashed line) and excited state absorption (red solid line) of MAPb 0.75 Sn 0.25 I 3 perovskite films. Ground state absorption edge is magnified for the comparison. Excited state absorption was recorded 1.5 ps after the pump excitation at 365 nm wavelength with 1.6 μj/cm 2 fluence. 6
Figure S10. Pseudo color plots and line plots of femtosecond transient absorption spectra for the perovskite films on glass (a, d), NiOx (b, e) and PEDOT:PSS (c, f) substrates. Figure S11. (a) Decay dynamics of PB1 and PB2 for MAPb0.75Sn0.25I3 perovskite films up to initial 10 ps. Fast decay of PB1 is followed by appearance of PB2 as reported in the literature.[s16] (b) Long-time scale decay of PB2 depending on the interlayers. 7
Figure S12. X-ray diffraction spectra of MA 1-y FA y Pb 0.75 Sn 0.25 I 3 perovksites with FA + content of 0%, 25%, 50%, 75% and 100%. 8
Figure S13. The typical J-V characteristic (a) and steady-state photocurrent measurement (b) of the MA 0.5 FA 0.5 PbPb 0.75 Sn 0.25 I 3 PVSCs with device area of 10 mm 2 measured under AM 1.5 illumination. The steady-state photocurrent measurement was performed with an applied voltage of 0.66 V at the maximum power point. For the measurement, 16 mm 2 solar cells were measured by applying a shadow mask with an aperture area of 10 mm 2 as shown in the inserted figure. Figure S14. Normalized ultraviolet photoelectron spectra of MA 0.5 FA 0.5 Pb 0.75 Sn 0.25 I 3 perovskites. Figure S9b is the magnified figure of Figure S9a. 9
Figure S15. SEM image of the compositional MA 0.5 FA 0.5 Pb 0.75 Sn 0.25 I 3 perovskite. Figure S16. EQE spectra of the MA 1-y FA y Pb 0.75 Sn 0.25 I 3 perovksites with FA + content of 0%, 25%, 50%, 75% and 100%. 10
Figure S17. The steady-state photocurrent measurement of the MA 0.5 FA 0.5 PbPb 0.75 Sn 0.25 I 3 PVSC with an applied voltage of 0.66 V at the maximum power point under AM1.5 illumination in air. Figure S18. Evolution of Photovoltaic parameters of the MAPb 0.75 Sn 0.25 I 3 perovskite solar cells measured under AM 1.5 illumination in ambient air with humidity of 30% to 40%. 11
Figure S19. Evolution of Photovoltaic parameters of the compositional MA 0.5 FA 0.5 Pb 0.75 Sn 0.25 I 3 perovskite solar cells measured under AM 1.5 illumination in ambient air with humidity of 30% to 40%. 12
Figure S20. Evolution of Photovoltaic parameters of the compositional MA 0.5 FA 0.5 Pb 0.75 Sn 0.25 I 3 perovskite solar cells measured under AM 1.5 illumination in the inert nitrogen atmosphere. 13
Figure S21. The transmittance spectrum of sputtered back ITO electrode. Figure S22. Hysteresis measurement of the semitransparent MAPbI 3 perovskite solar cells at a scan rate of 0.01 V s -1 under AM 1.5 illumination. 14
Figure S23. The steady-state photocurrent measurement of the semitransparent MAPbI 3 perovskite solar cells with an applied voltage of 0.88 V at the maximum power point. Figure S24. The stability of the semitransparent MAPbI 3 perovskite solar cells stored in ambient condition with humidity of 30% to 40%. η and η 0 represent the time-resolved and the original efficiency. 15
Table S1. Photovoltaic parameters of the MA 1-y FA y Pb 0.75 Sn 0.25 I 3 perovskite solar cells measured under AM 1.5 illumination. MA 1-y FA y Pb 0.75 Sn 0.25 I 3 Bandgap (ev) V OC (V) J SC (ma/cm 2 ) FF PCE (%) y=0 1.35 0.82±0.01 22.44±0.52 0.78±0.01 14.35±0.57 y=0.25 1.34 0.80±0.01 22.52±0.45 0.77±0.01 13.87±0.49 y=0.50 1.33 0.78±0.01 23.03±0.57 0.79±0.01 14.19±0.53 y=0.75 1.33 0.70±0.03 16.55±0.87 0.65±0.03 7.53±1.01 y=1 1.31 0.75±0.02 18.08±0.96 0.54±0.04 7.32±0.97 Average values with standard deviation. The data for each sample were obtained from 20 devices. 16
Reference [S1] D. P. McMeekin, G. Sadoughi, W. Rehman, G. E. Eperon, M. Saliba, M. T. Hörantner, A. Haghighirad, N. Sakai, L. Korte, B. Rech, M. B. Johnston, L. M. Herz, H. J. Snaith, Science 2016, 351, 151. [S2] P. Löper, S.-J. Moon, S. M. De Nicolas, B. Niesen, M. Ledinsky, S. Nicolay, J. Bailat, J.-H. Yum, S. De Wolf, C. Ballif, Phys. Chem. Chem. Phys. 2015, 17, 1619. [S3] T. Todorov, T. Gershon, O. Gunawan, Y. S. Lee, C. Sturdevant, L.-Y. Chang, S. Guha, Adv. Energy Mater. 2015, 5, 1500799. [S4] C. D. Bailie, M. G. Christoforo, J. P. Mailoa, A. R. Bowring, E. L. Unger, W. H. Nguyen, J. Burschka, N. Pellet, J. Z. Lee, M. Gratzel, R. Noufi, T. Buonassisi, A. Salleo, M. D. McGehee, Energy Environ. Sci. 2015, 8, 956. [S5] Y. Yang, Q. Chen, Y.-T. Hsieh, T.-B. Song, N. D. Marco, H. Zhou, Y. Yang, ACS Nano 2015, 9, 7714. [S6] S. Albrecht, M. Saliba, J. P. Correa Baena, F. Lang, L. Kegelmann, M. Mews, L. Steier, A. Abate, J. Rappich, L. Korte, R. Schlatmann, M. K. Nazeeruddin, A. Hagfeldt, M. Gratzel, B. Rech, Energy Environ. Sci. 2016, 9, 81. [S7] F. Fu, T. Feurer, T. Jager, E. Avancini, B. Bissig, S. Yoon, S. Buecheler, A. N. Tiwari, Nat. Commun. 2015, 6. [S8] F. Jiang, T. Liu, B. Luo, J. Tong, F. Qin, S. Xiong, Z. Li, Y. Zhou, J. Mater. Chem. A 2016, 4, 1208. [S9] J. H. Heo, S. H. Im, Adv. Mater. 2015, DOI: 10.1002/adma.201501629. [S10] J. P. Mailoa, C. D. Bailie, E. C. Johlin, E. T. Hoke, A. J. Akey, W. H. Nguyen, M. D. McGehee, T. Buonassisi, Appl. Phys. Lett. 2015, 106, 121105. [S11] L. Kranz, A. Abate, T. Feurer, F. Fu, E. Avancini, J. Löckinger, P. Reinhard, S. M. Zakeeruddin, M. Grätzel, S. Buecheler, A. N. Tiwari, J. Phys. Chem. Lett. 2015, 6, 2676. [S12] J. Werner, C.-H. Weng, A. Walter, L. Fesquet, J. P. Seif, S. De Wolf, B. Niesen, C. Ballif, J. Phys. Chem. Lett. 2016, 7, 161. [S13] C.-C. Chen, S.-H. Bae, W.-H. Chang, Z. Hong, G. Li, Q. Chen, H. Zhou, Y. Yang, Mater. Horiz. 2015, 2, 203. [S14] P. Loper, S.-J. Moon, S. Martin de Nicolas, B. Niesen, M. Ledinsky, S. Nicolay, J. Bailat, J.-H. Yum, S. De Wolf, C. Ballif, Phys. Chem. Chem. Phys. 2015, 17, 1619. [S15] Z. Li, P. P. Boix, G. Xing, K. Fu, S. A. Kulkarni, S. K. Batabyal, W. Xu, A. Cao, T. C. Sum, N. Mathews, L. H. Wong, Nanoscale 2016, 8, 6352. [S16] G. Xing, N. Mathews, S. Sun, S. S. Lim, Y. M. Lam, M. Grätzel, S. Mhaisalkar, T. C. Sum, Science 2013, 342, 344. 17