Two-dimensional (2D) hybrid perovskites have emerged as a promising class of optoelectronic materials, offering an extraordinary combination of photophysical tunability, mechanical flexibility, and enhanced environmental stability over their 3D counterparts. Among these, fluorinated layered perovskites such as (4-fluorophenethylammonium)₂PbI₄ (F-PEAI) have shown remarkable potential for photodetection. By exploiting their stability in ambient conditions and compatibility with atmospheric fabrication, we have developed planar photodetectors achieving responsivities exceeding 1100 A/W, detectivities in the 10¹⁷ Jones regime, and ultrawide linear dynamic ranges (up to 228 dB), and ultra-fast time response rivalling that of commercial 2 GHz Si photodiodes all without the need for complex passivation layers or atomically flat substrates. These devices can be fabricated on flexible platforms and are fully functional even on curved surfaces, making them uniquely suited for wearable and flexible technologies [1]. Coating them with bio-derived materials such as beeswax further enhances their environmental resilience and biocompatibility, enabling operation in aqueous and contaminated media and opening new possibilities in health monitoring and medical diagnostics [2].

A critical barrier to advancing these technologies lies in understanding and mitigating the role of defect states and charge carrier dynamics in multi-functional devices. We have introduced Threshold Voltage Transient Spectroscopy (TVTS) as a novel in situ method to characterise sub-gap traps and their dynamics within fully functional 2D perovskite devices operating as both field-effect transistors and high-gain photodetectors. This technique is non-invasive, i.e. it does not affect the operation of the devices, and it reveals the interplay between trap states and carrier transport under realistic working conditions, offering key insights at any given temperature without the need for detailed Arrhenius plots.  Finally, I will present recent advances on lead-free perovskite photodetectors based on antimony halide compounds, synthesized via wafer-scale magnetron sputtering. These devices deliver strong UV–visible performance and responsivity up to 3.3 A/W with high dynamic range and detectivity, providing a sustainable and scalable pathway toward non-toxic perovskite optoelectronics.