Introduction to Space Charge Effects in Semiconductors

This short Introduction into Space Charge E?ects in Semiconductors is designed for teaching the basics to undergraduates and show how space charges are created in semiconductors and what e?ect they have on the el- tric?eldandthe energybanddistributioninsuchmaterials,andconsequently on the current–voltage characteristics in semiconducting devices. Such space charge e?ects were described previously in numerous books, fromtheclassicsofSpenkeandShockleytothemorerecentonesofSeegerand others.Butmanymoredetailedinformationwereonlyavailableintheoriginal literatureandsomeofthemnotatall.Itseemstobeimportanttocollectallin a comprehensive Text that can be presented to students in Physics, Electrical Engineering, and Material Science to create the fundamental knowledge that is now essential for further development of more sophisticated semiconductor devices and solar cells. This book will go through every aspect of space charge e?ects and - scribe them from simple elementaries to the basics of semiconductor devices, systematically and in progressing detail. For simplicity we have chosen this description for a one-dimensional se- conductorthatpermitsasimpledemonstrationoftheresultsgraphicallywi- out requiring sometimes confusing perspective rendering. In order to clarify the principles involved, the book starts with a hy- thetical model, by assuming simple space charge distributions and deriving their e?ects on ?eld and potential distributions, using the Poisson equation. Itemphasizestheimportantsignrelationsoftheinterreactingvariables,space charge, ?eld, and potential (band edges). It then expands into simple semiconductor models that contain an abrupt nn-junction and gives an example of important space chargelimited currents, + as observed in nn -junctions.