The lack of thermal stability of perovskite solar cells is hindering the progress of this technology towards adoption in the consumer market. Different pathways of thermal degradation are activated at different temperatures in these complex nanostructured hybrid composites. Thus, it is essential to explore the thermal response of the mesosuperstructured composite device to engineer materials and operating protocols. Here we produce devices according to four well-established recipes, and characterize their photovoltaic performance as they are heated within the operational range. The devices are analysed using transmission electron microscopy as they are further heated in situ, to monitor changes in morphology and chemical composition. We identify mechanisms for structural and chemical changes, such as iodine and lead migration, which appear to be correlated to the synthesis conditions. In particular, we identify a correlation between exposure of the perovskite layer to air during processing and elemental diffusion during thermal treatment.
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G.D., S.C. and C.D. acknowledge funding from ERC under grant number 259619 PHOTO EM. C.D. acknowledges financial support from the EU under grant number 312483 ESTEEM2. F.M., L.C. and A.D.C. acknowledge funding from ‘Polo Solare Organico’ Regione Lazio, the ‘DSSCX’ MIUR-PRIN2010 and FP7 ITN ‘Destiny’. G.D. and S.C. thank F. de la Peña and P. Burdet for assistance with PCA analysis.
The authors declare no competing financial interests.
Supplementary Figures 1-9 (PDF 861 kb)
Sample A: montage of STEM-HAADF images upon heating. (AVI 13147 kb)
Sample B: montage of STEM-HAADF images upon heating. (AVI 16477 kb)
Sample C: Montage of STEM-HAADF images upon heating. (AVI 30350 kb)
Sample D: montage of STEM-HAADF images upon heating. (AVI 26096 kb)
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Divitini, G., Cacovich, S., Matteocci, F. et al. In situ observation of heat-induced degradation of perovskite solar cells. Nat Energy 1, 15012 (2016). https://doi.org/10.1038/nenergy.2015.12
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