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Updated: Feb 25, 2026

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films
Published on: September 8, 2017
Broadband-Emitting 2 D Hybrid Organic-Inorganic Perovskite Based on Cyclohexane-bis(methylamonium) Cation
Ishita Neogi1, Annalisa Bruno1,2, Damodaran Bahulayan1
1Energy Research Institute, Nanyang Technological University, Research Techno Plaza, X-Frontier Block, Level 5, 50 Nanyang Drive, 637553, Singapore, Singapore.
Abstract:
A new broadband-emitting 2 D hybrid organic-inorganic perovskite (CyBMA)PbBr4 based on highly flexible cis-1,3-bis(methylaminohydrobromide)cyclohexane (CyBMABr) core has been designed, synthesized, and investigated, highlighting the effects of stereoisomerism of the templating cation on the formation and properties of the resulting perovskite. The new 2 D material has high exciton binding energy of 340 meV and a broad emission spanning from 380 to 750 nm, incorporating a prominent excitonic band and a less intense broad peak at room temperature. Significant changes in the photoluminescence (PL) spectrum were observed at lower temperatures, showing remarkable enhancement in the intensity of the broadband at the cost of excitonic emission. Temperature-dependent PL mapping indicates the effective role of only a narrow band of excitonic absorption in the generation of the active channel for emission. Based on the evidences obtained from the photophysical investigations, we attributed the evolution of the broad B-band of (CyBMA)PbBr4 to excitonic self-trapped states.
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