Plastic electronics is a concept that emerged forty years ago, with the discovery of electrically conductive polymers. Ten years later, the first electronic devices using organic solids in place of the ubiquitous inorganic semiconductors were realised. The best achievement of plastic electronics is constituted by Organic Light-Emitting Diodes (OLEDs) that equip the display of many smartphones, and even TV sets. The objective of this course is to provide a comprehensive overview of the physics of plastic electronic devices. After taking this course, the student should be able to demonstrate theoretical knowledge on the following subjects: Concept of organic semiconductors; Charge carrier transport in polymeric and organic semiconductors; Optical properties of organic semiconductors; Charge injection from metals to organic solids; Operating mode of the main plastic electronic devices: Organic light-emitting diodes (OLEDs), organic photovoltaic cells (OPVs) and organic field-effect transistors (OFETs).