Ultraviolet photodetector using pn junction formed by transferrable hollow n-TiO nano-spheres monolayer.

We report an ultraviolet (UV) photodetector with a universally transferable monolayer film with ordered hollow TiO spheres on p-GaN. After forming a TiO monolayer film by unidirectional rubbing of hollow TiO spheres on a polydimethylsiloxane (PDMS) supporting plate, we used a 5% polyvinyl alcohol (PVA) aqueous solution to transfer the film onto the target substrate. The PVA/TiO monolayer film was detached from the PDMS film and transferred to the p-GaN/AlO substrate.