In this paper, we describe the formation of colloidal Si/Ge semiconductor nano-particles by electrochemical etching of Ge quantum dots (GEDOT), Silicon Germanium graded layers (GRADE) and Silicon Germanium multi-quantum well (MQW) structures which are prepared on Silicon wafers using low pressure chemical vapor deposition (LPCVD) technique. The formation of Si/Ge nano-particles is verified by transmission electron microscope (TEM) images and photoluminescence (PL) measurements. The Si/Ge nano-particles obtained from GEDOT and GRADE structures, gave blue emissions, upon 250 nm, and 300 nm UV excitations. However, the nano-particles obtained from the MQW structure did exhibit various color emissions (orange, blue, green and red) upon excitation with 250 nm, 360 nm, 380 nm and 400 nm wavelength light. (C) 2012 Elsevier B.V. All rights reserved.