Self organization is a natural way of arranging the things. All the forces in nature have a tendency to arrange the things in a well patterned and ordered way. The devices fabricated by self organization of nanoparticles show very interesting electrical and optical characteristics which can be controlled by precisely changing the structure of layer stacks and properties of the materials used. In this book the multilayer devices fabricated by layer-by-layer self assembly process using colloidal Au(~20nm) and ZnS(~30nm) nanoparticles are discussed. A remarkable improvement in the electrical and optical properties of deposited layers can be brought by controlling the pH of the colloidal solutions and deposited films using buffer solutions during the assembly process. This book also covers the complex conduction phenomena in these devices by discussing the similarities between the onset voltage and current values of different sized array structures. The experimental results in this book may act a guideline for engineers and scientists in the field of Microelectronics for exploring future fabrication techniques of electronic circuits and devices.