Sunny Fency, Chakkingal Parambil Priyakumari, Kalarikkal Nandakumar, Subila Kurukkal Balakrishnan
International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala, India.
Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, India.
Dalton Trans. 2025 May 20;54(20):8159-8168. doi: 10.1039/d5dt00325c.
Lead-free halide perovskites have been explored ardently for optoelectronic applications. Organic-inorganic hybrid halide perovskites have shown promise with novel optical properties, bandgap tuning and improved carrier dynamics, while introducing a quantum well structure. Herein, phenylethyl ammonium (PEA), an organic cation, was incorporated into cesium bismuth bromide (CBB) to enhance its multi-quantum well structure and synthesize organic-inorganic hybrid nanosheets of PEA-doped cesium bismuth bromide (PEA:CBB). Optimal doping conditions led to the formation of stable layered PEA:CBB hybrid nanosheets, evidenced by XRD and HRTEM analyses. DFT calculations revealed a minimum-energy structure in which PEA adopts a horizontal alignment between the inorganic slabs of CBB. The incorporation of PEA introduces new electronic states, resulting in extended luminescence tails and altered carrier lifetime. Third-order non-linear optical characterization of pristine and hybrid particles revealed that the multi-quantum well structure and additional trap states induced by PEA increase the two-photon absorption coefficient and reduce the optical limiting threshold of CBB. The present study indicates conceivable relevance of lead-free bismuth-based halide perovskites and their variants in optical limiting applications.
