دانشگاه کاشان مهندسی و مدیریت انرژی 2345-2951 15 3 2026 02 20 Ultra-Broadband Light Trapping in Thin-Film Silicon Solar Cells Using Optimized Slanted Tooth-Shaped Gratings به دام انداختن نور در سلول‌های خورشیدی سیلیکونی فیلم نازک با استفاده از شبکه‌های شیاردار دندانه‌دار بهینه‌شده 115355 10.22052/eem.2026.258112.1154 FA عارف پیربداقی دانشجوی دکتری رشته نانو الکترونیک دانشگاه کاشان محمود نیکوفرد نانوالکترونیک/پژوهشکده نانو/دانشگاه کاشان/کاشان Journal Article 2025 12 19 This superior performance originates from the advanced broadband light-trapping mechanism provided by the meticulously engineered slanted grating geometry with a 300 nm period, which substantially amplifies photon absorption while preserving outstanding electrical properties. These results establish a clear and practical route toward realizing cost-effective, ultrahigh-efficiency thin-film silicon solar cells for next-generation scalable photovoltaic applications.The global imperative to transition towards sustainable energy systems, driven by the critical need to combat climate change and meet escalating energy demands, has positioned solar photovoltaics (PV) as a cornerstone technology for the future energy landscape [1-3]. Solar energy possesses exceptional potential with theoretical capabilities exceeding 10²³ watts, while associated costs have experienced a remarkable 90% reduction over the past decade [4,5]. Within the photovoltaic domain, silicon solar cells maintain overwhelming market dominance with over 95% share, leveraging fundamental advantages including abundant raw material availability as the second most abundant element in Earth's crust, long-term stability exceeding 25 years, and mature processing technologies [6,7]. Recent advances have pushed silicon heterojunction solar cells to certified efficiencies of 26.81% with fill factors up to 86.59% on industry-grade silicon wafers [8], demonstrating continuous progress in conversion efficiency. This paper reports the design and optimization of an ultrahigh-efficiency thin-film silicon solar cell featuring broadband light trapping through a precisely engineered slanted grating architecture. The device, with a periodicity of 300 nm, consists of a 100 nm aluminum (Al) back reflector, a 110 nm p-type silicon active layer incorporating slanted grating structures, and a 45 nm n-type silicon capping layer. Comprehensive optical and electrical characterizations were conducted using Lumerical FDTD and CHARGE solvers, respectively. Beginning with a planar baseline configuration, remarkable performance improvement was realized by introducing slanted grating teeth and meticulously optimizing critical geometric parameters—namely the inter-tooth gap spacing, tooth height, and slant angle. The optimized configuration achieves an inter-tooth gap of 260 nm, tooth height of 90 nm, and slant angle of 40°, yielding an impressive average optical absorption of 84% across the solar spectrum. The electrical characteristics are equally remarkable, demonstrating a short-circuit current density of 44.41 mA/cm², open-circuit voltage of 0.580 V, power conversion efficiency of 20.58%, and fill factor of 0.798