Near-field vector analysis of plasmonic structures enhancement on infrared photodetectors

Abstract

In this work, we fabricated and compared two complimentary plasmonic structures: the metallic circular disc array and the 2 dimensional subwavelength hole array (2DSHA). The near-field electric-field (E-field) vector distributions of the two different plasmonic structures are analyzed. We also investigated the different plasmonic structure enhancements on quantum dots infrared photodetectors (QDIP). To fully ascertain the plasmonic enhancements in QDIPs, it is crucial to understand the E-field vector distributions in the plasmonic enhanced QDIP and identify their contributions. The E-field vertical extension of different plasmonic structures and their overlap with the quantum dot (QD) active regions are also simulated. Our studies indicate that the overlapping of the E-field vectors with the QD active region is critical to improve the QDIP performance. Detailed results and analysis will be discussed in the paper. We believe that the vector field analysis not only advances the knowledge of E-field components in plasmonic structures and their interaction with the QDs, but also provides the design guidance for high performance plasmonic enhanced optoelectronic devices.