Surface Plasmon-Enhanced Nano-photodetector for Green Light Detection

Light manipulation is vitally important for one- dimensional semiconductor nanostructure-based photodetec- tors which have great potential in future optoelectronic cir- cuits, imaging technique, and light-wave communication. In this paper, we reported a plasmonic gold nanoparticle (AuNP)-decorated nano-photodetectorforgreen light sensing. It is found that the as-fabricated device exhibits obvious in- crease in light absorption in the range from 400 to 550 nm, after functionalization of plasmonic AuNPs. Further device performance analysis reveals that the photocurrent of the plas- monic photodetector was increased by more than sevenfold, compared with that without coating. What is more, both responsivity and detectivity are found to increase as well. According to theoretical simulation based on the finite ele- ment method (FEM), the observed enhancement in device performance can be attributed to the surface plasmon- induced direct electron injection from the metal nanoparticles to the semiconductor nanostructures.