Surfaces and Interfaces
- 3.2k Downloads
The preparation of clean surfaces requires special techniques and ultrahigh vacuum. In such surfaces, ions undergo relaxation and reconstruction. Surfaces and interfaces reflect and refract Bloch waves; in addition, bound states may appear in their vicinity. These so-called surface states may refer to individual electrons or to collective oscillations such as surface phonons or surface plasmons. As the size of the devices is entering deeper into the nanoregime, the importance of the latter is rapidly increasing. The concept of the work function is introduced and methods for its measurement are presented together with a simple approximate formula for its calculation. The p–n homojunction in the absence or in the presence of an external voltage is examined in some details. This junction can act as a rectifier and as a light emitting diode; under illumination acts as a battery. The metal-semiconductor junction called Schottky barrier behaves in a similar way as the p–n junction. The field effect transistor is briefly presented.
KeywordsWork Function Minority Carrier Depletion Region External Voltage Bloch Wave
Unable to display preview. Download preview PDF.
- In the book by Ashcroft and Mermin [SS75]: See pp. 354-364 for the work function and its measurements; pp. 367–371 for electronic surface states; and pp. 590–613 for p–n junctions.Google Scholar
- For semiconductor and other solid state devices, consult the books by R. Dalven, Introduction to Applied Solid State Physics, 2nd ed. Plenum Press, New York, 1990 and by S.M. Sze, Physics of Semiconductor Devices, 2nd ed., Wiley, New York, 1981 [Se121].Google Scholar