Upconversion nanoparticles induce the reduction of graphene oxide for nanoscale optical writing

Nanoscale optical writing enables high-density optical data storage. However, current techniques usually require high laser beam intensity with high energy consumption and short device lifetime. Upconversion nanoparticles (UCNPs) have shown great potential for high-density optical data storage due to their exceptional luminescence emissions. In addition, UCNPs have enabled low-power STED microscopy. We show that UCNPs can induce the reduction of graphene oxide (GO) at the nanoscale. Dual-beam super-resolution irradiation was used to write features in UCNP-conjugated GO with lateral feature size at the nanoscale and inhibition intensity of <15 MW/cm^2. This approach might offers a convenient and energy-efficient solution for the storage demands in the Data Age.