Universal transfer printing of micelle templated nanoparticles using plasma functionalized graphene.

Nanostructure incorporation into devices plays a key role in improving performance, yet processes for preparing 2D arrays of colloidal nanoparticles tend not to be universally suitable, particularly for soft and oxygen sensitive substrates for organic and perovskite based electronics. Here, we show a method of transferring reverse micelle deposited (RMD) nanoparticles (perovskite and metal oxide) on top of an organic layer, using a functionalized graphene carrier layer for transfer printing. As the technique can be applied universally to RMD nanoparticles, we used magnetic (γ-Fe2O3) and luminescent (methylammonium lead bromide (MAPBr3)) nanoparticles to validate the transfer printing methodology. The strong photoluminescence from the MAPBr3 under UV illumination and high intrinsic field of the γ-Fe2O3 as measured by magnetic force microscopy (MFM), coupled with Raman measurements of the graphene layer, confirm that all components survive the transfer printing process with little loss of properties. Such an approach to introducing uniform 2D arrays of nanoparticles onto sensitive substrates opens up new avenues to tune device interfacial properties.