Fast response ZnO/PVA nanocomposite-based photodiodes modified by graphene quantum dots

Abstract

In this paper, a new class of the polymer-based photodetectors is introduced. Poly (vinyl alcohol) is used as the host polymer and ZnO@graphene quantum dots utilized as the filler of the polymer matrix. The specifications of the fabricated photodiodes are improved by exploiting the unique characteristics of graphene quantum dots (GQD). The manufactured photodiode, based on ZnO@GQD/PVA nanocomposite, indicates short rise time of 0.06 s and responsivity of 46.5 AW−1. The enhanced responsivity and transient time compared to ZnO/PVA photodetectors, are attributed to the graphene quantum dot encapsulation. Also, it achieves lower dark current and higher signal to noise ratio due to the creation of a Schottky barrier at the interface of ZnO@GQD core-shell structure. Moreover, the photoluminescence emission of prepared thin films using GQD is significantly increased in the blue and ultraviolet spectral range to make it a potential candidate for the light emitting devices.