27th Symposium on Photonics and Optics (SPO 2026)

Element Mixing in Aziridinium based Hybrid Perovskites towards Tunable Optoelectronic Properties

Th3.1

5 Nov 2026, 13:35

30m

Online (Zoom)

Invited Talk Sustainable Materials and Technologies for Optoelectronics and Sensors Sustainable Materials and Technologies for Optoelectronics and Sensors

Speaker

Dr Illia Guralskyi (Taras Shevchenko National University of Kyiv)

Description

Hybrid organic-inorganic metal halide perovskites are promising semiconductors for photovoltaic and light-emitting applications owing to their compositional flexibility and tunable optoelectronic properties. In this presentation, aziridinium-based three-dimensional perovskites are discussed as a versatile platform for band-gap engineering through halide substitution and B-site metal alloying.
Three series were studied: mixed bromide–iodide (AzrH)PbBr_xI_3-x, mixed chloride–bromide (AzrH)PbBr_xCl_3-x, and mixed lead–tin (AzrH)Pb_xSn_1-xBr₃ perovskites, where AzrH denotes the aziridinium cation. Their structural and optical properties were investigated using single-crystal and powder X-ray diffraction, diffuse reflectance spectroscopy, and photoluminescence measurements, complemented by density functional theory (DFT) calculations.
All investigated systems demonstrate substantial compositional control over their structural and electronic properties. Halide substitution preserves the cubic perovskite framework while modifying lattice parameters and optical band gaps. In the mixed bromide-iodide series, the band gap can be tuned from 1.57 to 2.23 eV. The chloride-bromide compounds exhibit systematic band-gap variation accompanied by composition-dependent photoluminescence, with emission maxima shifting from 445 to 504 nm as the bromide content increases. In both systems, preferential incorporation of one halide relative to its precursor proportion highlights the importance of verifying the final material composition. Complementarily, Pb–Sn alloying enables effective band-gap reduction from 2.41 eV for (AzrH)SnBr₃ to 1.95 eV for the equimolar composition, demonstrating pronounced band-gap bowing associated with interactions between Pb- and Sn-derived electronic states. The mixed-metal compounds retain a cubic structure at room temperature across the investigated composition range, while exhibiting composition-dependent temperature-induced phase transitions.
These findings establish aziridinium-based perovskites as a versatile materials platform for tailoring semiconductor properties through complementary anion and cation-site engineering. The demonstrated control over crystal structure, optical absorption, and emission provides a foundation for developing hybrid perovskites with targeted properties for next-generation optoelectronic applications.