1、中文中文 4600 字，字，2800 英文单词，英文单词，1.5 万英文字符万英文字符 附附 录录 附录附录 A:外文资料翻译外文资料翻译原文部分原文部分 Semiconductor A semiconductor is a solid material that has electrical conductivity between those of a conductor and an insulator; it can vary over that wide range either permanently or dynamically.1 Semiconductors are impo
2、rtant in electronic technology. Semiconductor devices, electronic components made of semiconductor materials, are essential in modern consumer electronics, including computers, mobile phones, and digital audio players. Silicon is used to create most semiconductors commercially, but dozens of other m
3、aterials are used. Bragg reflection in a diffuse lattice A second way starts with free electrons waves. When fading in an electrostatic potential due to the cores, due to Bragg reflection some waves are reflected and cannot penetrate the bulk, that is a band gap opens. In this description it is not
4、clear, while the number of electrons fills up exactly all states below the gap. Energy level splitting due to spin state Pauli exclusion A third description starts with two atoms. The split states form a covalent bond where two electrons with spin up and spin down are mostly in between the two atoms
5、. Adding more atoms now is supposed not to lead to splitting, but to more bonds. This is the way silicon is typically drawn. The band gap is now formed by lifting one electron from the lower electron level into the upper level. This level is known to be anti-bonding, but bulk silicon has not been se
6、en to lose atoms as easy as electrons are wandering through it. Also this model is most unsuitable to explain how in graded hetero-junction the band gap can vary smoothly. Energy bands and electrical conduction Like in other solids, the electrons in semiconductors can have energies only within certain bands (ie. ranges of levels of energy) between the energy of the ground state, corresponding to electrons tightly bound to the atomic nuclei of the material, and the free electron energy,
