“Black silicon” is a novel type of material, which can absorb incident sun light by approximately 98 %, generating more current than ordinary Si (60%). Usually “black silicon” consists of needle like spikes. If a light is shone on such a surface, it repeatedly bounces back and forth between the spikes in a way that most of it never comes back out again. Black Si” is an excellent material for solar cells. It absorbs light more effectively, generating hundreds times more current than conventional Si. Besides, this material could also be used to make infrared detectors, a new application for Si. The aim of the study is to elaborate a new controllable method of “black Si” formation on a Si wafer by Nd:YAG laser radiation.