Figure 11
Micrograph of the wet-pit sample and a defect (silver) on the surface. Because the No.1~No.4 samples had different micro-nano hybrid structures, the reflectance showed different variation trends and the absorption had different values. The wet-pit line has a higher reflectance than the other five lines over the wavelength range from 700 nm to 1200 nm because the nanostructures on the pits did not grow well on the profile of the pits, as shown in Fig. 11. Nanostructures cannot be seen in the holes but can be seen at the surface, and the partial silicon (holes) can reflect more light energy than the rest of the silicon (top surface). Figure 11 also indicates a defect on the surface because the silver particles found there were not removed by the HNO3 solution. Silver particles hardly existed in tips but few in pits.
