Tunnelling and Negative Resistance Phenomena in Semiconductors presents a critical review of tunneling theory and shows how this leads to the negative resistance phenomena in pn junctions. The physics, technology, and circuitry of semiconductor negative resistance devices are surveyed. The book challenges the conventional assumptions of tunneling theory and proposes an alternative approach that allows the possibility of a change in energy during tunneling. It also introduces the reader to the manufacture, operation, and applications of semiconductor negative resistance devices. Comprised of five chapters, this volume begins by presenting a logical physical interpretation of the wavefunction with its so-called ill-behaved nature and considering other consequences of the energy distribution effect. The next chapter is devoted to the tunneling effect through tunnel diodes along with other properties of this device. The circuitry and technology of tunnel diodes as well as backward and Zener diodes are then examined, along with negative conductance devices that are used as microwave sources. The final chapter is concerned with negative conductance switching devices. This book is intended for students and practitioners in the fields of physics and electronics.