Upconverted Hot Electrons and Solvated Electrons from Mn-Doped Semiconductor Nanocrystals for Photochemistry: Perspective

Hot electrons photogenerated in semiconductor nanocrystals enable powerful redox reactivity due to their large excess energy and their capability for long-range transfer over high energy barriers. Among various strategies for hot electron generation, Mn-mediated Auger upconversion in Mn-doped semiconductor nanocrystals has emerged as a particularly effective method. This process generates hot electrons with large excess energies, a fraction of which can even exceed the vacuum level, enabling their emission as free electrons into the vacuum or their injection into surrounding liquid media to form reactive solvated electrons. These unique properties of the upconverted hot electrons open new pathways for driving thermodynamically and kinetically demanding reactions in various liquid media. This Perspective discusses recent advances in Mn-mediated hot electron upconversion, diverse chemical transformations enabled by upconverted hot electrons, and the important issues that need to be addressed to harness the full potential of upconverted hot electron-driven photochemistry.