Broadband plasmonic absorption of C-shape groove array for hot-electron detection

In this paper, a C-shape groove array on gold/silicon/aluminum layers is proposed and numerically inves-tigated. The mode coupling of plasmon resonances in the same structure leads to a broadband absorption. We found that a simulated broadband absorption (from 1390 nm to 1507 nm) above 90% was obtained by controlling the geometric parameters. Furthermore, the origin of the broadband absorption is studied, and the enhanced effects for hot electron detection is investigated. Different from other reported results, our proposed structure can bring a broadband absorption in a simple structure, and can be an easy manufacturing method for the hot-electron detection.