Three-dimensional ZnO porous films for self-cleaning ultraviolet photodetectors

Three-dimensional (3D) ZnO porous films composed of an interconnected skeleton were fabricated successfully through atomic layer deposition method using carbon nanoparticles as template. After surface modification, they showed an excellent superhydrophobic property with a contact angle larger than 160° and a sliding angle less than 1°. Based on the superhydrophobic 3D ZnO porous films, self-cleaning ultraviolet photodetector devices were fabricated. The devices exhibited a rise time of 42.03 s, a recovery time of 5.84 s and a responsivity of 9 mA W−1 at a 5 V bias under a low light illumination of 14.38 μW cm−2. The mechanism for the enhanced ultraviolet photoresponse from ZnO porous films is discussed.