Stanford Matters: Water Additives Boost Efficiency of Purple Cobalt Mining Photodiodes

• Blue, green, red, and near-infrared perovskite light-emitting diodes (PeLEDs) have achieved high external quantum efficiency (EQE), and their energy efficiency is approaching that of III-V-based LEDs. Beyond the visible light range, UV light offers great promise for many applications such as disinfection. However, PeLEDs do not perform well in the violet/UV region, and poor film quality has been reported to hinder the performance of violet PeLEDs.
  

• Daniel N. Congreve et al. from Stanford University designed the crystallization process of spin-coated two-dimensional perovskite by adding water to the precursor solution, thereby improving the uniformity of the perovskite film. The resulting improved film uniformity, coupled with the reduced size of the nanoplates, reduces leakage current and promotes faster recombination rates. The fabricated PeLEDs provided bright violet emission at 408 nm with a maximum external quantum efficiency of 0.41%, a five-fold improvement over the control device. This work demonstrates feasible steps to realize cost-effective and efficient ultraviolet PeLEDs.
  

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• Water additives improve the efficiency of violet perovskite light-emitting diodes, Matter, 2023.

  https://doi.org/10.1016/j.matt.2023.05.018