Fabrication of microstructures on silicon by multiple beam holographic method using nanosecond laser pulses

Micron-sized grating structures (MGS) and sub-micron sized dot arrays (DA) were generated on silicon target by multiple shots of interfering nanosecond laser beams. The mechanism to form MGS and DA were analyzed and it is found that the obtained structures have a negative shape of the interference pattern. The most major size of the periodic structure is 500 nm. The optical properties of these nanostructures are also investigated. The silicon DAs function as both absorber and antireflection layers, which offer a promising approach to enhance the solar cell energy conversion efficiency.