“…21–28 However, the reported long-wavelength, i.e. , deep-red and near-infrared (NIR) LECs, which have great potential applications in bio-imaging, telecommunication, night-vision displays, and chemical sensing, commonly showed low device efficiencies, 29–61 hindering their commercialization. In these reported studies, deep-red LECs based on phosphor-sensitized fluorescence 29,30 outperform other types of deep-red LECs, i.e.…”