Book excerpt: This book covers evolution, concept and applications of modern semiconductor devices such as tunnel field effect transistors (TFETs), vertical super-thin body MOSFETs, ion sensing FETs (ISFETs), non-conventional solar cells, opto-electro mechanical devices and thin film transistors (TFTs). Comprising of theory, experimentation and applications of devices, the chapters describe state-of-art methods and techniques which shall be highly assistive in having an overall perspective on emerging technologies and working on a research area. The book is aimed at the scholars, enthusiasts and researchers who are currently working on devices in the contemporary era of semiconductor devices. Additionally, the chapters are lucid and descriptive and carry the potential of serving as a reference book for scholars in their undergraduate studies, who are looking ahead for a prospective career in semiconductor devices.