This book deals with some emerging semiconductor devices and their applications in terms of electronic circuits. The basic concept plays a key role in development of any new electronic devices and circuits. The implementation of complex integrated circuits becomes easier with understanding of basic concepts of solid state devices and its circuit behavior. The book covers the latest trends in development of advanced electronic devices and applications for undergraduate, graduate and post graduate level courses. It combines the right blend of theory and practice to present a simplified and methodical way to develop researchers' understanding of the clarity between theoretical, practical and simulated results in the analysis of solid state devices, circuit characteristics and other important issues based on their applications. The book also covers the broad applications of electronic devices in biomedical and low power portable smart IOT systems. This book is well organized into 13 chapters. Chapters 1 to 4 cover design of low power FET devices compatible to technology scaling trends meeting required performance enhancement in terms of power, delay and speed. Chapter 5 and 6 are focused on analog application of CMOS technology. Chapter 7 describes power MOSFET design with advance materials for lowest possible on-resistance resulting into enhance performance. Chapter 8 deals with biomedical application of advance electronic devices introducing new materials and structure. Chapter 9 introduces a neuromorphic model and real-time simulation for the study of biological neuron model in the human body on circuit level. Chapter 10 and 11 presents the applications of sensors growing over a wide range of sensing targets along with advance sensing technology for human-computer interaction. Chapter 12 and 13 describe optoelectronic devices like photodetectors, optical sensors and solar cells etc.