A new laser method is elaborated for nanocones’ formation on a surface of such semiconductors as: elementary semiconductors Si and Ge and semiconductor solid solutions - Si1-x Gex /Si and Cd1-x ZnxTe. Strong change of the optical, mechanical and electrical properties of the semiconductors after irradiation by Nd:YAG laser are explained by the presence of Quantum Confinement Effect (QCE) in nanocones where radius is equal to or smaller than Bohr’ effective radius of electron, hole or exciton. “Blue shift” of photoluminescence spectra (Fig.1) and “red shift” of phonon LO line in Raman spectrum are explained by exciton and phonon QCE in nanocones, correspondently. Asymmetry of the photoluminescence band in the spectrum of Si nanocones is explained by 1D graded band gap structure. Experimental data on nanocones formation on a surface of Si, Ge and their solid solution and CdZnTe crystal and their optical properties are presented. Two-stage mechanism of nanocones’ formation on a surface of the semiconductors is proposed [1]. The first stage of the mechanism is characterized by the formation of a thin strained top layer, due to redistribution of point defects in temperature-gradient field induced by laser radiation. The second stage is characterized by mechanical plastic deformation of the stained top layer leading to arising of nanocones due to heating up of the top layer. Formation of nanocones can be applied for design of third generation solar cells, Si white light emitting diode, photodetector with selective or “bolometer” type spectral sensitivity and Si tip for field electron emitting with low work function