Rapid pace of electronic technology evolution and current economic climate compel a merger of such technical areas as low-power digital electronics, microwave power circuits, optoelectronics, etc., which collectively have become the foundation of today's electronic technology. This Workshop aims at encouraging active cross-fertilization of the different ""species"" in this electronic planet. The WOFE2015 had gather experts from academia, industry, and government agencies to review the recent exciting breakthroughs and their underlying physical mechanisms. This Monographs includes ten invited articles; cover topics ranging from Ultra-thin silicon nanowire solar cells, to hydrogen generation under illumination of GaN-based structures and from ultrafast response of nanoscale device structures to Power device optimization.