The strategic fluorination of organic spacers in 2D tin-halide perovskites has emerged as a compelling approach to improving the stability and optoelectronic performance of lead-free materials, yet the interpretation of these effects is often complicated by rapid, morphology-driven crystallization associated with traditional spin-coating methods [1]. In this work, we investigate nanoplatelets (submicrometric in thickness and > 10 µm of lateral size) of 4-fluoro-phenethylammonium tin iodide, (4F-PEA)₂SnI₄, made by the hot injection method. Leveraging the inherently low solubility of these tin-halide perovskites in n-octane, well-defined polycrystalline films 10-20 µm thick were formed for optical characterization [2]. In the temperature range of 25–300 K, steady-state photoluminescence (PL) and Time Resolved PL (TRPL) measurements were conducted, along with PL excitation spectra at 25 and 300 K. From the PL spectra, it is evident that the spectrum is predominantly composed of two components, each peaking at 1.894 and 1.931 eV (655 and 642 nm) at 25 K. Based on PLE spectra and micro-PL imaging conducted at 80 K and room temperature, it has been determined that the low-energy PL contribution originates from exciton recombination at the center of the nanoplatelets, while the high-energy PL contribution is attributed to exciton recombination spatially localized at their contour edge [3]. From the TRPL measurements, we deduce decay times of approximately 400 and 240 ps at the high and low PL peak energies. These results are consistent with two different exciton populations: one with a two-dimensional character (located at the center of the nanoplatelet) and the second with lower dimensionality (situated at the nanoplatelet edge) [4]. Furthermore, amplified spontaneous emission (ASE) in backscattering geometry was investigated in similar films of nanoplatelets using a sub-ns pulsed laser at 532 nm with a repetition rate of 1 kHz. This investigation provides valuable information regarding the high radiative emission efficiency of these nanoplatelets. ASE is observed at the low energy side of the PL spectrum, approximately at 666 nm, where absorption is negligible. The threshold average power of ASE is 4 µW [5]. Notably, ASE is observed up to a temperature exceeding 100 K, further indicating the relatively high structural quality and reduced presence of nonradiative centers in these nanoplatelets, comparable to the state-of-the-art results in Ruddlesden-Popper perovskite phases, both lead and lead-free.