Interfacial amplification for graphene-based position-sensitive-detectors

Abstract

Position-sensitive-detectors (PSDs) based on lateral photoeffect have been widely used in diverse applications1–9, including optical engineering, aerospace and military fields. With increasing demand in long distance, low energy consumption, and weak signal sensing systems, the poor responsivity of conventional PSDs has become a bottleneck limiting their applications, for example, silicon p–n or p–i–n junctions2–5, or other materials and architectures6–10. Herein, we present a high-performance graphene-based PSDs with revolu-tionary interfacial amplification mechanism. Signal amplification in the order of ~ 104 has been demonstrated by utilizing the ultrahigh mobility of graphene and long lifetime of photo-induced carriers at the interface of SiO2/Si. This would improve the detection limit of Si-based PSDs from μW to nW level, without sacrificing the spatial resolution and response speed. Such interfacial amplification mechanism is compatible with current Si technology and can be easily extended to other sensing systems11,12. Figure 1a shows the representative schematic and the working.