Role of metal layer in improving the UV-photodetector performance of TiO2/Metal/TiO2/Si structure

In this paper, a new metallic thin film engineering aspect is proposed to achieve superior absorption for TiO2/Metal/TiO2 on Silicon substrate UV-based photodetectors (PDs). The overall device optical performance comparison with three dissimilar metallic layers (Au, Ti, and Ag) is performed numerically using accurate solutions of Maxwell׳s equations. A comprehensive study of the device optical parameters such as the integral absorption, reflection, and rejection ratio is carried out, in order to reveal the device optical performance for UV optical interconnects and environment monitoring applications. We find that the optical performance are considerably improved as compared to the conventional design, where the proposed design offers superior integral absorption and lower total reflection with an acceptable rejection ratio in comparison with those provided by the conventional one. These improvements suggest the opportunity for optimizing the proposed design using particle swarm optimization (PSO) approach for achieving higher optical performance, where excellent capability is recorded in enhancing the device optical behavior. The obtained results make the proposed device very efficient for compatible CMOS modern technology.