Yb3+/Er3+ Co-doped CsPbCl3 nanocrystals for 1.54-μm light-emitting diodes

Lanthanide-doped perovskite nanocrystals (NCs) have emerged as attractive emitters operating at telecommunication wavelengths. Nevertheless, achieving efficient lanthanide incorporation generally demands high synthesis temperatures (>240 °C), which complicates control over NC size and uniformity. In this work, we revealed that by replacing excess Pb 2+ with lanthanide halides, Ostwald ripening was effectively suppressed, resulting in precise size tuning and enhanced doping. This versatile lanthanide halide–mediated strategy yields highly monodisperse Yb/Er-codoped CsPbCl 3 NCs that exhibit a record photoluminescence quantum yield (21.2%) at 1.54 μm among colloidal perovskite systems. A light-emitting diode (PeLED) was fabricated, showing nearly pure 1.54 μm emission, achieving the peak external quantum efficiency (EQE) of 0.464% under low driving voltage of 2.7 V. In conclusion, the development of 1.54-μm Er-PeLEDs presents new prospects for integrated light sources.