Optics and Photonics Society of Iran

In this paper a novel anti-reflection coating based on silicon nano-bars is designed and compared to conventional anti-reflection coatings. Silicon nano-bars with optimized size and period are designed and embeded on the active layer on top of which a 100nm Si3N4 layer is coated. As a result the proposed layer stack, an intermediate layer with refractive index amid the two layers is formed and a graded refractive index anti-reflection coating is achieved which has a substantial effect on reduction of reflection spectra. Such structure effects reflection even at 45̊ illumination angle. To validate our claim, the proposed structure as well as four conventional anti-reflection coating is simulated and through computation of reflection factor and silicon absorption spectra, it is shown that our structure outperform the already existed anti-reflection coatings and additionally strongly couples the incident light to the active layer.