Aromatic Additives Boost the Terahertz Properties of Mixed Halide Perovskite Single Crystals.

Mixed halide perovskite (MHP) materials are promising candidates for photonic applications, owing to their tunable bandgap and pronounced optoelectronic properties. However, phase segregation in these materials severely impacts their scalability. The additive engineering (AE) strategy in the growth of most perovskite crystals (PSCs) has proven more effective. Current work focused toward enhancing the stability of 6.67% Cl-doped methylammonium lead(II) bromide single crystals (MHSCs) using aromatic nitrogen-based additives. Modified MHSCs showed enhanced terahertz (THz) radiation transmission and reflection. Moreover, the evidence from powder X-ray diffraction (p-XRD), X-ray photoelectron spectroscopy (XPS), and THz transmission in modified MHSCs revealed the mitigated phase segregation in modified MHSCs.