“…The lanthanides doped inorganic upconversion (UC) materials with excellent optical properties have significant applications in wide fields, for example, temperature sensing [ 1 ], solar light conversion [ 2 ], optical sensors [ 3 ], or security applications [ 4 ], bioimaging [ 5 ], optical heating [ 6 ], optogenetics [ 7 ], nanoscopy [ 8 ], nanoscale optical writing [ 9 ], etc. Inorganic phosphors, compared with organic dyes or quantum dots, have several advantages, including a longer excited state lifetime, sharp emission bandwidths, and cheaper and more environmentally friendly synthesis [ 4 ].…”