This course is designed to introduce important semiconductor optoelectronic devices and applications, such as light emitting diode (LED), solid state Laser, photo-detector, and solar cell, etc. It provides students with fundamental knowledge in optoelectronics as well as critical device design engineering. Developed on top of the fundamental knowledge covered in 18-310, the course begins with discussion on basic optics and device physics; it then focuses on operational principle, design engineering, and important applications of the devices. Special topics on novel nanoscale electronics and optoelectronics including nanowire, nano-particle light emitting and photovoltaic devices will also be discussed. In addition, an introduction to low-cost, flexible organic devices, e.g. display and solar cells will be presented.