Metal halide perovskites possess desirable optical, material, and electrical properties which have had substantial impact on next-generation optoelectronics. However, given the toxicity of lead, alternative lead-free perovskite semiconductors are needed. By fully replacing lead with rare-earth elements, one can simultaneously address toxicity concerns and achieve comparable optoelectronic performance. Here, we demonstrate the synthesis of two-dimensional europium halide perovskite nanoplatelets governed by the formula L2EuX4 where L is an organic ligand and X is a halide anion. The structure, morphology, and composition of the nanoplatelets are confirmed by XRD, AFM, and XPS. Deep blue-emitting PEA2EuBr4 perovskite nanoplatelets are synthesized in both the solution- and solid-states with photoluminescence emission centered at 446 nm and CIE color coordinates of (0.1515, 0.0327) and (0.1515, 0.0342), respectively. Additionally, near-ultraviolet PEA2EuCl4 perovskite nanoplatelets are synthesized in both the solution- and solid-states with photoluminescence emission centered at 400 nm and 401 nm, respectively. Overall, europium halide perovskite nanoplatelets offer a lead-free alternative for deep blue, violet, and near-ultraviolet light emission \unicodex2013 charting new pathways for optoelectronics in this energy regime.
@article{arxiv.2511.10873,
title = {Lead-Free Europium Halide Perovskite Nanoplatelets},
author = {Sebastian Fernández and Divine Mbachu and Manchen Hu and Han Cui and William Michaels and Pournima Narayanan and Tyler K. Colenbrander and Qi Zhou and Da Lin and Ona Segura Lecina and Guosong Hong and Daniel N. Congreve},
journal= {arXiv preprint arXiv:2511.10873},
year = {2025}
}