Light trapping enhancement via structure design

Light trapping is of great importance in many applications including photodetectors and solar cells. Silicon-based structures and hybrid devices were designed and studied to reduce reflection, thus enhance light trapping. The typical pillar array was analyzed concerning the pillar radius and distance between pillars first. The result showed that light reflection could be reduced from the range of 0.35-0.45 to the range of 0-0.3 with wavelength from 400 to 700 nm. What should be noted is that optimal size for light trapping changed when wavelength varied. Furthermore, hybrid structure was designed to increase light trapping. The results showed that the structure with random quantum dots (QDs) covering pillar array coated with two-dimensional (2D) material is an effective way to confine the light reflection under 0.1, thus promoting light trapping.