Three-dimensional (3D) and two-dimensional (2D) lead iodide-based perovskite materials: A comparison of material stability and ammonia gas sensitivity

Abstract

Despite enormous attention on lead halide perovskite, the stability of material is of major concern that is in critical needs of attention. Lead iodide-based CH3NH3PbI3 (3D) perovskite (MIP) and (H2C=C(CH3)CO2CH2CH2NH3)2PbI2Cl2 (2D) perovskite (AMP) were synthesised and investigated for different days under various storage conditions. After few days, the original surface morphology of both samples changed and small scattered particles were found. RMS (roughness) of MIP decreased from 51.78 to 18.00 nm, while AMP showed otherwise (from 37.70 to 95.52 nm). The increase in roughness favours the diffusion of ammonia gas molecules into perovskite and consequently increases gas response properties. Based on roughness, FWHM, crystallite size, crystallinity and lattice strain parameters, it can be concluded that 2D AMP exhibited better sensing properties than 3D MIP although the finding shows superior stability of 3D over 2D due to the self-crystallization of 3D perovskite materials.