Single-step fabricated disordered pyramidal nanostructures for large-scale broadband visible light absorber with high-temperature stability

While the advances in material science have led to excellent absorption and bandwidth for visible light absorbers, the sophisticated and time-consuming fabrication in micro and nano scales makes it the bottleneck of large-scale manufacturing. Without complex structural patterning, an absorber consisting of a single layer of chromium film is fabricated on a 4-inch silicon wafer by single-step physical vapor deposition. Benefiting from disordered pyramidal nanostructures, this absorber achieves beyond 90% absorption in the range of 300 to 850 nm. Compared to the chromium film without nanostructures, it improves the absorption by more than 80%, and obtains a more uniform absorption with relative absorption bandwidth (RAB) of 96.3%. Simulated results demonstrate the excellent absorption is attributed to numerous disordered pyramidal nanostructures with rough texture and random gaps. This absorber shows the great potential of broadband absorption with angle insensitivity in visible region and sustainable light capture at high temperatures, and its fabrication is facile, low-cost, and compatible with mass production and CMOS process.