Single-Step Preparation of Graphene Oxide Transparent Electrode by PECVD and its Application in a Fast-Response UV-A-Selective Pyrophototronic Device

Graphene oxide (GO) is a promising material which is a potential candidate as a transparent electrode for various applications. GO is synthesized by plasma-enhanced chemical vapour deposition on glass substrate in a single-step process without the use of any catalyst or post-transfer treatment. To exploit the versatility of GO as a transparent electrode, a self-powered ultraviolet (UV) light detection device is fabricated, and the usefulness of GO as a transparent electrode is demonstrated. A p-n junction is fabricated by depositing ZnO and NiO over the GO film. ZnO thin film is used as a working material for a UV sensing device whose non-centrosymmetric atomic arrangement in the hexagonal lattice makes it pyroelectric and useful for pyrophototronic device. The fabricated pyrophototronic device works on a selective UV-A band of the electromagnetic spectrum from 360 nm to 400 nm, with a sharp peak at 375 nm. The responsivity of the device is measured as 0.41 mA/W at 375 nm. The response of the device is very fast with a response time of 484 mu s.