Synthesis, Molecular Formula and Thermal Stability of Hybrid Perovskites \( A_2SnBr_4 \) with \( A = C_4H_9NH_3^+ \) and \( C_5H_{11}NH_3^+ \) Selvi Anasha, Djulia Onggo and Muhamad A. Martoprawiro
Inorganic and Physical Chemistry Division, Faculty of Mathematics and Natural Sciences
Bandung Institute of Technology - ITB
Abstract
Hybrid perovskites are typical of smart materials that have been widely developed and applied as a photodetector material, solar cells and LED (Light Emitting Diode). 2D hybrid perovskites with the formula \( A_2MX_4 \) is formed by organic cation \( (A^+) \) and inorganic anion \( [MX_4]^{2-} \) usually uses divalent metal elements such as lead (Pb). Pb-based perovskite has good electronic properties but has high toxicity to the health and environments. In this research, we prepared lead-free hybrid perovskites \( A_2SnBr_4 \) with \( A^+ \) are butylammonium \( (C_4H_9NH_3^+) \) and amylammonium \( (C_5H_{11}NH_3^+) \). The synthesis was carried out by one-pot reaction of the reactants in the form of SnO, HBr, amine compounds and \( H_3PO_2 \) at room and elevated temperature \( 90^oC \). The yellow crystalline product was obtained under ambient light and green under ultraviolet light. Based on the elemental analysis, the products have the molecular formula of \( (C_4H_9NH_3)_2SnBr_4.HBr \) and \( (C_5H_{11}NH_3)_2SnBr_4.HBr \) with a reasonable yield of 54-72%. The thermal stability of butylammonium tetrabromotin(II) is \( 185^oC \) lower than amylammonium tetrabromotin(II) compound, \( 198^oC. \)
Keywords: hybrid perovskites, \( (C_4H_9NH_3)_2SnBr_4.HBr, \) \( (C_5H_{11}NH_3)_2SnBr_4.HBr, \) one pot reaction, thermal stability
