Performance assessment of Gr/Si/Gr UV-photodetector: Design and optimization of graphene interdigitated electrodes

摘要

In this paper, a new p-Si-MSM-UV-photodetector (PD) based on graphene interdigitated electrodes (GrIE) is proposed to achieve the dual role of enhanced time response and superior responsivity. An overall performance comparison between the proposed GrIE/p-Si-based MSM PD design and the conventional Au/p-Si structure is carried out using new comprehensive analytical models. The obtained results indicate the outstanding capability of the proposed design for improving the MSM PD performance. Such enhancement can be attributed to the suppressed degradation related-shadowing effects, where the use of graphene transparent electrodes open up the route for improving the device optical behavior. In order to address the trade-off between speed and photoresponse properties, a new Figure of Merit (FoM) parameter that combines both performance criteria is proposed. The impact of GrIE geometrical parameters on the device FoM is also analyzed. Moreover, Particle Swarm Optimization (PSO) approach is proposed to boost up the device performance. It is found that the optimized GrIE/p-Si design pinpoints a new path toward simultaneously reaching a high responsivity (770 mA/W) with reduced time response (3 mu s). Therefore, the proposed design methodology not only outperforms the conventional Au/p-Si PD, but also enables bridging the gap between high-speed and ultrasensitive properties, making it suitable for high-performance sensing applications using 2D materials.