Ferroelastic Fingerprints in Methylammonium Lead

Transcription

1 Supporting information Ferroelastic Fingerprints in Methylammonium Lead Iodide Perovskite Ilka M. Hermes, Simon A. Bretschneider, Victor W. Bergmann, Dan Li, Alexander Klasen,, Julian Mars,, Wolfgang Tremel, Frédéric Laquai,, Hans-Jürgen Butt, Markus Mezger,, Rüdiger Berger, Brian J. Rodriguez, and Stefan A. L. Weber,,* Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, Germany Institute of Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, Mainz, Germany Solar and Photovoltaics Engineering Research Center (SPERC), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 10, Mainz, Germany School of Physics and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland * Corresponding Author: S. A. L. Weber; webers@mpip-mainz.mpg.de

2 Figure S1 Figure S1. Vertical piezoresponse amplitude on MAPbI 3 film in dependence of externally applied AC voltage at f Drive =300 khz (scan angle = 0 ). The linear fit (red line) was applied until 2.5 V AC voltage and exhibited slope of 16.6 ± 1.7 pm/v corresponding to the resonance enhanced piezoelectric coefficient d zz *. The vertical piezoresponse amplitude was measured as a function of the applied AC voltage on a domain oriented in a 115 angle with respect to the cantilever. Up until an AC voltage of 2.5 V the response is linear with a slope of 16.6 ± 1.7 pm/v. 1 AC voltages higher than 3 V caused damages of the sample surface. With 16.6 ± 1.7 pm/v the piezoelectric coefficient d zz * measured here is higher than the previously reported value of 5 pm/v. 2 But as we measured at 300 khz, close to the contact resonance frequency of 315 khz, it is likely that the piezoresponse is further enhanced by the resonance.

3 Figure S2 Figure S2. Lateral PFM measurement on MAPbI 3 film on ITO without PEDOT:PSS (a) Topography, (b) PFM phase, (c) PFM amplitude (V AC = 2.5 V; f Drive = 600 khz). The lateral piezoresponse was measured on a MAPbI 3 film prepared without the PEDOT:PSS layer directly on ITO to obtain information in the influence of the substrate on the twin domain formation. On the grains that crystallized directly on ITO we observed the same periodic pattern in the piezoresponse as on grains that crystallized on PEDOT:PSS.

4 Figure S3 Figure S3. Intensity distributions of (a) the (110) and (b) the (200) Bragg reflections of MAPbI 3 vs. the azimuthal angle χ. The intensity distribution of the (110) Bragg reflection shows an intensity maximum at χ = 90, i.e. close to the specular condition (Figure S2). For the (200) reflection two intensity maxima at χ = 90 ±45. These results suggest that the (110) crystal planes of the MAPbI 3 are preferentially orientated parallel to the surface.

5 Figure S4 Figure S4. Ferroelectric switching experiment on MAPbI 3 film with a scan rate of 0.8 V/s. (a) PFM phase and (b) PFM amplitude in dependence of the applied DC voltage. The ferroelectric switching experiments on the MAPbI 3 films were performed with a scan rate of 0.8 V/s. We did not observe a ferroelectric switching event in the PFM phase. The absence of a ferroelectric hysteresis loop in the PFM phase indicates the absence of out-of plane switchable polarization in the (110) plane of the MAPbI 3 grains.

6 Figure S5 Figure S5. UV-vis absorption spectra of MAPbI 3 film. Figure S5 shows the UV-vis absorption spectra of the perovskite film. The broad absorption of the film covers the visible spectrum with an absorption onset at 800 nm and a peak at 750 nm characteristic for MAPbI 3. 3 An additional peak at around 500 nm is probably caused by the presence of crystalline lead iodide, which was also observed in the XRD measurement in Figure References 1. Kalinin, S. V.; Rodriguez, B. J.; Jesse, S.; Shin, J.; Baddorf, A. P.; Gupta, P.; Jain, H.; Williams, D. B.; Gruverman, A. Vector Piezoresponse Force Microscopy. Microscopy and Microanalysis 2006, 12 (03), Coll, M.; Gomez, A.; Mas-Marza, E.; Almora, O.; Garcia-Belmonte, G.; Campoy-Quiles, M.; Bisquert, J. Polarization Switching and Light-Enhanced Piezoelectricity in Lead Halide Perovskites. J. Phys. Chem. Lett. 2015, 6 (8), Kazim, S.; Nazeeruddin, M. K.; Grätzel, M.; Ahmad, S. Perovskite as Light Harvester: A Game Changer in Photovoltaics. Angew. Chem. Int. Ed. 2014, 53 (11), Christians, J. A.; Miranda Herrera, P. A.; Kamat, P. V. Transformation of the Excited State and Photovoltaic Efficiency of CH3NH3PbI3 Perovskite upon Controlled Exposure to Humidified Air. J. Am. Chem. Soc. 2015, 137 (4), Conings, B.; Drijkoningen, J.; Gauquelin, N.; Babayigit, A.; D'Haen, J.; D'Olieslaeger, L.; Ethirajan, A.; Verbeeck, J.; Manca, J.; Mosconi, E.; Angelis, F. D.; Boyen, H.-G. Intrinsic Thermal Instability of Methylammonium Lead Trihalide Perovskite. Advanced Energy Materials 2015.