This investigation into the optoelectronic properties of the mixed halide 2D perovskite material PEA2PbCl1Br3 has yielded significant insights into the complex mechanisms governing their performance in PeLEDs. The introduction of TmPyPB as an additional electron transport layer enhances charge carrier confinement and reduces non-radiative losses, as evidenced by both optical measurements and electronic device analysis. Our work culminates in the successful demonstration of solution processed PeLEDs with ultraviolet emission below 400 nm, surpassing the spectral limitations of previously reported devices while achieving reasonable EQE values. These findings not only highlight the potential of 2D perovskites in next-generation optoelectronics but also pave the way for further exploration into novel device architectures and material compositions, with the ultimate goal of realizing highly efficient, stable, and commercially viable ultraviolet electroluminescent devices.