Formamidinium halide salts as precursors of carbon nitrides

13 figures, 6 tables.-- Supplementary information available.
Pyrolysis of formamidinium halide salts (FAI, FABr) results in a new type of amorphous carbon nitride materials with a mass fraction of 40–50% nitrogen content. Pyrolysis temperature drives final chemical composition, morphology, optical and electrical properties of the material independently of the halide precursor and identifying triazine ring, instead of typical heptazine unit, as the main building block of this material. We elaborated a temperature dependent mechanism of formation for these materials and foresee its potential value as native passivation layer in the field of perovskite solar cells.
E.J.J-P acknowledges the funding support from MCIN/AEI/10.13039/501100011033 and European Union NextGenerationEU/PRTR (project grants PID2019-107893RB-I00 and EIN2020-112315, respectively). M.H. acknowledges the funding support from MCIN/AEI/10.13039/501100011033 for the Ramón y Cajal fellowship (RYC-2018-025222-I) and the project PID2019-108247RA-I00. R.A. acknowledges funding from the Spanish MICINN (project grant PID2019-104739 GB-100/AEI/10.13039/501100011033). RA also acknowledge to Government of Aragon (project DGA E13-20R (FEDER, EU)) and European Union H2020 program “ESTEEM3” (823717). A.A-C acknowledges financial support from Spanish MCIN/AEI/10.13039/501100011033 under project PID2019-104272RB-C51/AEI/10.13039/501100011033 and the Diputación General de Aragón under project T03_20R (Grupo Reconocido).