Design of InAs nanosheet arrays with ultrawide polarization-independent high absorption for infrared photodetection

InAs nanowires have been considered as good candidates for infrared photodetection. However, one-dimensional geometry of a nanowire makes it unsuitable for broadband light absorption. In this work, we propose and design InAs nanosheet arrays to achieve polarization-independent, angle-insensitive, and ultrawide infrared absorption. Simulations demonstrate that two-dimensional InAs nanosheets can support multiple resonance modes, thus leading to a strong and broadband absorption from visible light to mid-wave infrared. Moreover, we can tune polarization-dependent property in InAs nanosheets to be polarization-insensitive by forming a nanosheet based clover-like and snowflake-like nanostructures. We further optimized the design of InAs nanosheet arrays based on such structures and achieved high absorption (up to 99.6%) covering a broad wavelength range from 500 to 3200 nm. These absorption properties are much superior to their nanowire and planar film counterparts, making it attractive for infrared photodetection applications. The architecture of such nanostructures can provide a promising route for the development of high-performance room-temperature broadband infrared photodetectors.