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F. Matteocci

Publications and source records attributed to F. Matteocci.

2 recordsLinked to original sources

Thin single-crystal perovskite detector for high-energy charged particles

The organometal halide perovskites (OMHP) semi-conductors have shown recently a strong potential as radiation detectors, beside the well-known success in photovoltaics and as photo-detectors. Many studies have been published on X-rays detection, and a few studies about detection of alpha, beta-particles and protons. Less literature is present for high energy charged particles. OMHP-based devices for tracking and real-time monitoring for high energy particles may offer many advantages. OMHPs can be directly grown on pixelated electronics, even on curved substrates, without the need of complex and expensive bump-bonding procedures. Moreover, OMHPs have shown self-healing features after radiation exposure, which makes them attractive for high-flux applications. In this paper we report a device based on a thin single OMHP crystal, about 150 mum thick, directly grown on a patterned substrate through dewetting technique, able to detect high-energy charged particles in a high dynamic range of incident fluxes. A dedicated electronics circuit has been developed to match the expected time characteristics of the OMHP crystals. This is the first demonstration of thin OMHP single crystals being able to detect high energy charged particles of hundreds of MeV.

physics.ins-det

Effect of FABr Over-Stoichiometry on the Morphology and Optoelectronic Properties of Wide-Bandgap FAPbBr_3 Films

In this study, we investigate the impact of formamidinium bromide (FABr) over-stoichiometry in the precursor solution on the optoelectronic properties and morphology of the resulting films of formamidinium lead bromide (FAPbBr_3). Optical characterization, including steady-state absorption, photoluminescence (PL), and femtosecond transient absorption spectroscopy, reveals a systematic blueshift in emission energy with increasing FABr content, attributed to the passivation of bromine vacancies and to the reduction of defect-assisted recombination. Power-dependent PL confirms this interpretation: the stoichiometric film exhibits a PL band due to donor-acceptor pair (DAP) recombination as identified by the typical excitation-dependent blueshift, whereas FABr-enriched samples show no evidence of DAP emission, indicating effective defect passivation. Additionally, morphological characterization shows a reduction in grain size with increasing FABr excess, indicating a trade-off between improved electronic quality and enhanced structural disorder. The film synthesized with a 5% excess of FABr provides the optimal balance, yielding the highest power conversion efficiency (6.26%), average visible transmittance (61.6%), and light utilization efficiency (3.85%). These results demonstrate that fine-tuning the precursor stoichiometry through controlled FABr addition represents a simple yet effective strategy to enhance the optoelectronic quality and performance of semitransparent perovskite solar cells.

cond-mat.mtrl-sci