Surface silicon nanostructure for enhancement of blue light absorption

Abstract

To enhance blue light absorption, a nanohole-array was designed and fabricated on the surface of silicon. The absorptivity of the silicon/nanohole-array composite structure was simulated with the finite-difference time-domain method. The result showed that, when the air filling factor f = 0.45, the period P = 400 nm, and the hole depth d = 0.5 μm, the absorptivity of the silicon was greater than 0.85 in the blue band and the average light absorption gain was about 0.61. A nanohole-array was fabricated with these structural parameters. The experimental results showed that the blue absorptivity of the silicon was greater than 0.91 and the average light absorption gain was about 0.63. For incident light at an angle of 60°, the absorptivity was greater than 0.73 in the blue band. The research demonstrated that the blue light could be absorbed at the deeper position of Si through the nanohole-array. This research may serve as a reference for the design and fabrication of silicon optoelectronic devices with high blue light quantum efficiency.