Detecting ionising radiation is vital for medical imaging, cancer therapy, and environmental monitoring, with expanding relevance in military and space technologies. Traditional scintillators such as CsI:Tl and LYSO:Ce require resource-intensive production often with toxic components, while organic scintillators like anthracene or stilbene offer fast responses but lower efficiencies. Metal halide perovskites have emerged as promising alternatives, combining large attenuation coefficients, high photoluminescence quantum yields, and short decay times. Their structural and chemical tailorability allows tuning of luminescent properties, leading to low-dimensional derivatives with tuneable emission, large Stokes shifts, and nanosecond lifetimes. This thesis presents a comprehensive investigation into the one-dimensional Rb2AgX3 (X = Cl, Br) metal halides, centred on advancing their development for applications in X-ray detection. The work explores an array of scalable, solution-based synthesis methods across multiple material formats from bulk single crystal and polycrystalline to colloidal nanocrystals, elucidating the relationships between structural control, compositional purity, and ultimately scintillation performance. Initial efforts focused on refining single-crystal and polycrystalline synthesis strategies, with the latter achieving the first reported phase-pure synthesis of both halide analogues via an optimised anti-solvent engineering route. Optical and radioluminescence measurements revealed characteristic excitonic behaviour and halide-specific emission pathways with Rb2AgCl3 displaying superior emission intensities, whereas the bromide consistently elicited a stronger X-ray induced response across crystal forms. These halide-dependent behaviours underscore the tunability of the Rb2AgX3 system and suggest distinct optimisation pathways for ionising radiation detection. The present work identifies halide-specific development targets, revealing compositional or structural routes for enhancing X-ray absorption in Rb2AgCl3 and defect engineering strategies for improving radiative efficiency of Rb2AgBr3. Subsequently, work investigated post-synthetic treatments of polycrystalline Rb2AgX3 where uniaxial pressure combined with low-temperature thermal processing were applied as strategies to enhance scintillation performance. Improvements in material densification, optical clarity and X-ray response were achieved whilst maintaining material thicknesses of > 250 µm. These findings underscore the importance of microstructural control in enhancing defect-mediated emission and scintillation efficiencies. To overcome processing limitations of bulk materials and enhance compatibility with device integration, development pivoted towards collodial Rb2AgX3 nanocrystals, enabling effective polymer encapsulation. The final research phase examined the viability of Rb2AgX3 nanocrystal synthesis for incorporation into polymeric matrices to form transparent nanocomposite scintillators that combined environmental protection with mechanical flexibility. Optimisation of a hot-injection method examined the influence of reaction conditions, ligand chemistry, and purification on nanocrystal quality. Their integration into PMMA and PDMS matrices was studied to minimise aggregation and preserve characteristic emission, delivering preliminary v work into future nanocomposite development. Collectively, this work establishes Rb2AgCl3 and Rb2AgBr3 as viable, lead-free scintillator materials which offer scalable processing routes, tunable optical properties, and promising X-ray performance. The findings advance the broader field of low-dimensional metal halide materials and open avenues for further material optimisation and device integration in scintillator applications.