000145242 001__ 145242 000145242 005__ 20241015122513.0 000145242 0247_ $$2doi$$a10.1039/c9ta06058h 000145242 0248_ $$2sideral$$a116263 000145242 037__ $$aART-2019-116263 000145242 041__ $$aeng 000145242 100__ $$0(orcid)0000-0001-6040-1920$$aJuarez-Perez, Emilio J.$$uUniversidad de Zaragoza 000145242 245__ $$aThermal degradation of formamidinium based lead halide perovskites into sym-triazine and hydrogen cyanide observed by coupled thermogravimetry-mass spectrometry analysis 000145242 260__ $$c2019 000145242 5060_ $$aAccess copy available to the general public$$fUnrestricted 000145242 5203_ $$aThe thermal stability and decomposition products of formamidinium, a widely used organic cation in perovskite solar cell formulation, were investigated. The thermal degradation experiments of formamidinium-based perovskites and their halide precursors were carried out under helium atmosphere and vacuum at a constant heating rate of 20 degrees C min(-1). In addition, pulsed heating steps were employed under illumination/dark conditions to simulate a more realistic working temperature condition for photovoltaic devices. The identification of gas decomposition products was based on the quadrupole mass spectrometry technique. The released amounts of sym-triazine, formamidine, and hydrogen cyanide (HCN) were observed to highly depend on the temperature. For the experimental conditions used in this study, sym-triazine was obtained as the thermal product of degradation at temperatures above 95 degrees C. Below this temperature, only formamidine and HCN generation routes were observed. The energy pathways of formamidinium thermal degradation under photovoltaic working temperature conditions were further assessed by density functional theory calculations. The results indicated that formamidinium was more resilient to thermal degradation and the release of irreversible decomposition products compared to methylammonium because of a larger enthalpy and activation energy obtained for the decomposition reactions. The HCN instantaneous concentration observed during the low temperature heating tests and the estimations of the maximum release of HCN achievable per meter-square of an FA based perovskite based solar cell were compared to acute exposure guideline levels of airborne HCN concentration. 000145242 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/ 000145242 590__ $$a11.301$$b2019 000145242 591__ $$aCHEMISTRY, PHYSICAL$$b17 / 159 = 0.107$$c2019$$dQ1$$eT1 000145242 591__ $$aMATERIALS SCIENCE, MULTIDISCIPLINARY$$b24 / 314 = 0.076$$c2019$$dQ1$$eT1 000145242 591__ $$aENERGY & FUELS$$b8 / 112 = 0.071$$c2019$$dQ1$$eT1 000145242 592__ $$a3.432$$b2019 000145242 593__ $$aChemistry (miscellaneous)$$c2019$$dQ1 000145242 593__ $$aRenewable Energy, Sustainability and the Environment$$c2019$$dQ1 000145242 593__ $$aMaterials Science (miscellaneous)$$c2019$$dQ1 000145242 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000145242 700__ $$aOno, Luis K. 000145242 700__ $$aQi, Yabing 000145242 7102_ $$15005$$2555$$aUniversidad de Zaragoza$$bDpto. Ing.Quím.Tecnol.Med.Amb.$$cÁrea Ingeniería Química 000145242 773__ $$g7, 28 (2019), 16912-16919$$pJ. mater. chem. A$$tJournal of Materials Chemistry A$$x2050-7488 000145242 8564_ $$s837992$$uhttps://zaguan.unizar.es/record/145242/files/texto_completo.pdf$$yPostprint 000145242 8564_ $$s2051248$$uhttps://zaguan.unizar.es/record/145242/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000145242 909CO $$ooai:zaguan.unizar.es:145242$$particulos$$pdriver 000145242 951__ $$a2024-10-15-10:50:35 000145242 980__ $$aARTICLE