An efficient broadband white-light photodetector: Combining visible-light-active ferroelectrics with 2D conductive intermediary RGO

Abstract

Hitherto, “smart” functional bismuth ferrite (BFO) has triggered intensive research to develop novel visible-light photodetectors to substitute silicon-based detectors. However, current BFO-based detectors still fall short of the requirements for white-light (WL) detection due to unsatisfactory sensitivity and response speed. In pursuit of simple and efficient BFO-based device paradigm, we propose an effective strategy to fill empty space among metallic silver electrode dot-matrix with continuous transparent conductive material by decorating reduced graphene oxide (RGO) nanosheets on top of semiconducting layer. The hybrid device structures, BFO/RGO/Ag and BFO/NiO/RGO/Ag, are systematically explored in comparison to pure BFO. The RGO sheet stands out as qualified transparent conductive intermediary to disrupt the potential barrier caused by ubiquitous metal-semiconductor contact. It is the synergistic action of RGO facilitating charge collection and heterostructure pattern of BFO/NiO that eventually contribute to boost optical-electrical response performances of BFO/NiO/RGO structure. Accordingly, the optimized response time constants of photocurrent rising and decay are lowered down to 16.01 ms and 11.76 ms, respectively. Such response speed can exceed most of BFO-based counterparts especially in the WL-detection. Consequently, we deliver a green and facile approach to push forward the high-speed WL photoelectric detection by combining visible-light-active ferroelectrics BFO with two-dimensional conductive RGO.