Mandana Jalali, Hamid Nadgaran, Daniel Erni,
Volume 11, Issue 2 (International Journal of Optics and Photonics (IJOP) Vol 11, No 2, Summer-Fall 2017)
Abstract
In this paper a novel anti-reflection (AR) coating based on silicon nano-bars is designed and its impact on the performance of crystalline silicon (c-Si) thin-film solar cells is extensively studied. Silicon nano-bars with optimized size and period are embedded on top of the active layer, under a 100nm Si3N4 layer. As a result of the proposed layer stack, an inhomogeneous intermediate layer with effective refractive index amid the two layers is formed and a graded refractive index AR coating is achieved, which has a substantial effect on broad, omnidirectional reduction of the reflection spectra. To validate our claim, the proposed structure as well as four conventional AR coatings are simulated and through the numerical analysis of both the spectral response of the reflection factor and the silicon active layer absorption spectra, it is shown that the proposed design outperforms conventional already existing AR coatings, and in addition provides a strong coupling of the incident light to the active layer, while improving the overall efficiency of the thin-film solar cell.
Maliheh Ranjbaran, Maryam Rezaei, Sattar Jalali, Mobina Sadat Maroufi,
Volume 17, Issue 2 (Summer-Fall 2023)
Abstract
Cataracts, along with presbyopia, is a common age-related vision problem that can indeed make it challenging to achieve clear vision. Multifocal intraocular lenses (IOLs) have emerged as a promising treatment option to improve vision in individuals with cataracts and presbyopia. With their unique design, these lenses provide adequate vision at multiple distances and reduce the dependency on glasses. In this study, we utilized the Liou-Brennan model in Zemax software to simulate a healthy eye and then introduced cataracts with presbyopia to the model. Subsequently, we applied treatment in the form of multifocal intraocular lenses. The improvements in the patient's vision were indicated using spot diagrams and modulation transfer function for three different viewing distances: far, intermediate, and near at three different entrance pupil diameters.
